Patent Application
20150343526
The present disclosure is generally related to a plunger in an injection molding or die casting machine, and, more specifically, the application of ultrasonic vibrations to molten material in the injection molding or die casting machine.
In injection molding and die casting, alloy(s) in a molten state is/are injected into a mold. Two issues may sometimes occur during the process. One is the lack of thermal homogeneity of the molten alloy. A second is the surface quality and filling characteristics of the alloy as it flows into the mold.
Some molten amorphous alloys are non-Newtonian fluids, meaning that under strain, the viscosity decreases. When melting such materials in an injection molding system, uniform temperatures in ranges appropriate to the meltable material should be implemented and maintained in order to produce quality molded parts.
A proposed solution according to embodiments herein for melting and molding materials includes applying ultrasonic vibrations to melting and/or molten material (e.g., metals or metal alloys) in an injection molding or die casting machine. The ultrasonic vibrations may be applied via a plunger tip, for example, and/or the mold, and/or the vessel or shot sleeve, and/or the melting chamber.
In one aspect of this disclosure, there is provided a plunger of an injection molding or die casting machine. The plunger has a plunger body and a plunger tip associated with the plunger body. The plunger tip has an end surface configured to directly contact a molten material used in injection molding in the injection molding or die casting machine. Also provided is a connector that is connected to an ultrasonic vibration generator that is associated with the injection molding or die casting machine. At least the end surface of the plunger tip is configured to vibrate at ultrasonic vibrations applied via the ultrasonic vibration generator and through the connector during injection of the molten material.
In another aspect of this disclosure, there is provided an injection molding or die casting machine comprising an ultrasonic vibration generator that is configured to apply ultrasonic vibrations during melting and injection of the molten material.
In yet another aspect of this disclosure, there is provided a method. The method is a method of injection molding a meltable material in an injection molding or die casting machine comprising a plunger, an ultrasonic transducer, a vessel configured to receive the meltable material for melting therein; and a mold for molding the molten material, wherein the plunger comprises a plunger body and a plunger tip configured to directly contact a molten material in the vessel and move the molten material from the vessel and to inject the molten material into the mold, and wherein the ultrasonic transducer is configured to apply ultrasonic vibrations to at least the plunger tip. The method includes: applying ultrasonic vibrations to at least the plunger tip of the plunger via the ultrasonic transducer; melting the meltable material into a molten state in the vessel; and forcing the molten material from the vessel and into the mold using the plunger. At least the plunger tip applies ultrasonic vibrations to the material during both the melting and the forcing of the material.
Also, in accordance with embodiments, the material for melting comprises a BMG feedstock, and a BMG part may be formed.
Other aspects and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.
All publications, patents, and patent applications cited in this Specification are hereby incorporated by reference in their entirety.
The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “a polymer resin” means one polymer resin or more than one polymer resin. Any ranges cited herein are inclusive. The terms “substantially” and “about” used throughout this Specification are used to describe and account for small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%.
Bulk-solidifying amorphous alloys, or bulk metallic glasses (“BMG”), are a recently developed class of metallic materials. These alloys may be solidified and cooled at relatively slow rates, and they retain the amorphous, non-crystalline (i.e., glassy) state at room temperature. Amorphous alloys have many superior properties than their crystalline counterparts. However, if the cooling rate is not sufficiently high, crystals may form inside the alloy during cooling, so that the benefits of the amorphous state can be lost. For example, one challenge with the fabrication of bulk amorphous alloy parts is partial crystallization of the parts due to either slow cooling or impurities in the raw alloy material. As a high degree of amorphicity (and, conversely, a low degree of crystallinity) is desirable in BMG parts, there is a need to develop methods for casting BMG parts having controlled amount of amorphicity.
Even though there is no liquid/crystallization transformation for a bulk solidifying amorphous metal, a “melting temperature” Tm may be defined as the thermodynamic liquidus temperature of the corresponding crystalline phase. Under this regime, the viscosity of bulk-solidifying amorphous alloys at the melting temperature could lie in the range of about 0.1 poise to about 10,000 poise, and even sometimes under 0.01 poise. A lower viscosity at the “melting temperature” would provide faster and complete filling of intricate portions of the shell/mold with a bulk solidifying amorphous metal for forming the BMG parts. Furthermore, the cooling rate of the molten metal to form a BMG part has to such that the time-temperature profile during cooling does not traverse through the nose-shaped region bounding the crystallized region in the TTT diagram of
The supercooled liquid region, the temperature region between Tg and Tx is a manifestation of the extraordinary stability against crystallization of bulk solidification alloys. In this temperature region the bulk solidifying alloy can exist as a high viscous liquid. The viscosity of the bulk solidifying alloy in the supercooled liquid region can vary between 1012 Pa s at the glass transition temperature down to 105 Pa s at the crystallization temperature, the high temperature limit of the supercooled liquid region. Liquids with such viscosities can undergo substantial plastic strain under an applied pressure. The embodiments herein make use of the large plastic formability in the supercooled liquid region as a forming and separating method.
One needs to clarify something about Tx. Technically, the nose-shaped curve shown in the TTT diagram describes Tx as a function of temperature and time. Thus, regardless of the trajectory that one takes while heating or cooling a metal alloy, when one hits the TTT curve, one has reached Tx. In
The schematic TTT diagram of
Typical differential scanning calorimeter (DSC) heating curves of bulk-solidifying amorphous alloys taken at a heating rate of 20 C./min describe, for the most part, a particular trajectory across the TTT data where one would likely see a Tg at a certain temperature, a Tx when the DSC heating ramp crosses the TTT crystallization onset, and eventually melting peaks when the same trajectory crosses the temperature range for melting. If one heats a bulk-solidifying amorphous alloy at a rapid heating rate as shown by the ramp up portion of trajectories (2), (3) and (4) in
The term “phase” herein can refer to one that can be found in a thermodynamic phase diagram. A phase is a region of space (e.g., a thermodynamic system) throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, index of refraction, chemical composition and lattice periodicity. A simple description of a phase is a region of material that is chemically uniform, physically distinct, and/or mechanically separable. For example, in a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, and the humid air over the water is a third phase. The glass of the jar is another separate phase. A phase can refer to a solid solution, which can be a binary, tertiary, quaternary, or more, solution, or a compound, such as an intermetallic compound. As another example, an amorphous phase is distinct from a crystalline phase.
The term “metal” refers to an electropositive chemical element. The term “element” in this Specification refers generally to an element that can be found in a Periodic Table. Physically, a metal atom in the ground state contains a partially filled band with an empty state close to an occupied state. The term “transition metal” is any of the metallic elements within Groups 3 to 12 in the Periodic Table that have an incomplete inner electron shell and that serve as transitional links between the most and the least electropositive in a series of elements. Transition metals are characterized by multiple valences, colored compounds, and the ability to form stable complex ions. The term “nonmetal” refers to a chemical element that does not have the capacity to lose electrons and form a positive ion.
Depending on the application, any suitable nonmetal elements, or their combinations, can be used. The alloy (or “alloy composition”) can include multiple nonmetal elements, such as at least two, at least three, at least four, or more, nonmetal elements. A nonmetal element can be any element that is found in Groups 13-17 in the Periodic Table. For example, a nonmetal element can be any one of F, Cl, Br, I, At, O, S, Se, Te, Po, N, P, As, Sb, Bi, C, Si, Ge, Sn, Pb, and B. Occasionally, a nonmetal element can also refer to certain metalloids (e.g., B, Si, Ge, As, Sb, Te, and Po) in Groups 13-17. In one embodiment, the nonmetal elements can include B, Si, C, P, or combinations thereof. Accordingly, for example, the alloy can include a boride, a carbide, or both.
A transition metal element can be any of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, rutherfordium, dubnium, seaborgium, bohrium, hassium, meitnerium, ununnilium, unununium, and ununbium. In one embodiment, a BMG containing a transition metal element can have at least one of Sc, Y, La, Ac, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, and Hg. Depending on the application, any suitable transitional metal elements, or their combinations, can be used. The alloy composition can include multiple transitional metal elements, such as at least two, at least three, at least four, or more, transitional metal elements.
The presently described alloy or alloy “sample” or “specimen” alloy can have any shape or size. For example, the alloy can have a shape of a particulate, which can have a shape such as spherical, ellipsoid, wire-like, rod-like, sheet-like, flake-like, or an irregular shape. The particulate can have any size. For example, it can have an average diameter of between about 1 micron and about 100 microns, such as between about 5 microns and about 80 microns, such as between about 10 microns and about 60 microns, such as between about 15 microns and about 50 microns, such as between about 15 microns and about 45 microns, such as between about 20 microns and about 40 microns, such as between about 25 microns and about 35 microns. For example, in one embodiment, the average diameter of the particulate is between about 25 microns and about 44 microns. In some embodiments, smaller particulates, such as those in the nanometer range, or larger particulates, such as those bigger than 100 microns, can be used.
The alloy sample or specimen can also be of a much larger dimension. For example, it can be a bulk structural component, such as an ingot, housing/casing of an electronic device or even a portion of a structural component that has dimensions in the millimeter, centimeter, or meter range.
The term “solid solution” refers to a solid form of a solution. The term “solution” refers to a mixture of two or more substances, which may be solids, liquids, gases, or a combination of these. The mixture can be homogeneous or heterogeneous. The term “mixture” is a composition of two or more substances that are combined with each other and are generally capable of being separated. Generally, the two or more substances are not chemically combined with each other.
In some embodiments, the alloy composition described herein can be fully alloyed. In one embodiment, an “alloy” refers to a homogeneous mixture or solid solution of two or more metals, the atoms of one replacing or occupying interstitial positions between the atoms of the other; for example, brass is an alloy of zinc and copper. An alloy, in contrast to a composite, can refer to a partial or complete solid solution of one or more elements in a metal matrix, such as one or more compounds in a metallic matrix. The term alloy herein can refer to both a complete solid solution alloy that can give single solid phase microstructure and a partial solution that can give two or more phases. An alloy composition described herein can refer to one comprising an alloy or one comprising an alloy-containing composite.
Thus, a fully alloyed alloy can have a homogenous distribution of the constituents, be it a solid solution phase, a compound phase, or both. The term “fully alloyed” used herein can account for minor variations within the error tolerance. For example, it can refer to at least 90% alloyed, such as at least 95% alloyed, such as at least 99% alloyed, such as at least 99.5% alloyed, such as at least 99.9% alloyed. The percentage herein can refer to either volume percent or weight percentage, depending on the context. These percentages can be balanced by impurities, which can be in terms of composition or phases that are not a part of the alloy.
An “amorphous” or “non-crystalline solid” is a solid that lacks lattice periodicity, which is characteristic of a crystal. As used herein, an “amorphous solid” includes “glass” which is an amorphous solid that softens and transforms into a liquid-like state upon heating through the glass transition. Generally, amorphous materials lack the long-range order characteristic of a crystal, though they can possess some short-range order at the atomic length scale due to the nature of chemical bonding. The distinction between amorphous solids and crystalline solids can be made based on lattice periodicity as determined by structural characterization techniques such as x-ray diffraction and transmission electron microscopy.
The terms “order” and “disorder” designate the presence or absence of some symmetry or correlation in a many-particle system. The terms “long-range order” and “short-range order” distinguish order in materials based on length scales.
The strictest form of order in a solid is lattice periodicity: a certain pattern (the arrangement of atoms in a unit cell) is repeated again and again to form a translationally invariant tiling of space. This is the defining property of a crystal. Possible symmetries have been classified in 14 Bravais lattices and 230 space groups.
Lattice periodicity implies long-range order. If only one unit cell is known, then by virtue of the translational symmetry it is possible to accurately predict all atomic positions at arbitrary distances. The converse is generally true, except, for example, in quasi-crystals that have perfectly deterministic tilings but do not possess lattice periodicity.
Long-range order characterizes physical systems in which remote portions of the same sample exhibit correlated behavior. This can be expressed as a correlation function, namely the spin-spin correlation function: G(x, x′)=s(x), s(x′)
.
In the above function, s is the spin quantum number and x is the distance function within the particular system. This function is equal to unity when x=x′ and decreases as the distance |x-x′| increases. Typically, it decays exponentially to zero at large distances, and the system is considered to be disordered. If, however, the correlation function decays to a constant value at large |x-x′|, then the system can be said to possess long-range order. If it decays to zero as a power of the distance, then it can be called quasi-long-range order. Note that what constitutes a large value of |x-x′| is relative.
A system can be said to present quenched disorder when some parameters defining its behavior are random variables that do not evolve with time (i.e., they are quenched or frozen)—e.g., spin glasses. It is opposite to annealed disorder, where the random variables are allowed to evolve themselves. Embodiments herein include systems comprising quenched disorder.
The alloy described herein can be crystalline, partially crystalline, amorphous, or substantially amorphous. For example, the alloy sample/specimen can include at least some crystallinity, with grains/crystals having sizes in the nanometer and/or micrometer ranges. Alternatively, the alloy can be substantially amorphous, such as fully amorphous. In one embodiment, the alloy composition is at least substantially not amorphous, such as being substantially crystalline, such as being entirely crystalline.
In one embodiment, the presence of a crystal or a plurality of crystals in an otherwise amorphous alloy can be construed as a “crystalline phase” therein. The degree of crystallinity (or “crystallinity” for short in some embodiments) of an alloy can refer to the amount of the crystalline phase present in the alloy. The degree can refer to, for example, a fraction of crystals present in the alloy. The fraction can refer to volume fraction or weight fraction, depending on the context. A measure of how “amorphous” an amorphous alloy is can be amorphicity. Amorphicity can be measured in terms of a degree of crystallinity. For example, in one embodiment, an alloy having a low degree of crystallinity can be said to have a high degree of amorphicity. In one embodiment, for example, an alloy having 60 vol % crystalline phase can have a 40 vol % amorphous phase.
An “amorphous alloy” is an alloy having an amorphous content of more than 50% by volume, preferably more than 90% by volume of amorphous content, more preferably more than 95% by volume of amorphous content, and most preferably more than 99% to almost 100% by volume of amorphous content. Note that, as described above, an alloy high in amorphicity is equivalently low in degree of crystallinity. An “amorphous metal” is an amorphous metal material with a disordered atomic-scale structure. In contrast to most metals, which are crystalline and therefore have a highly ordered arrangement of atoms, amorphous alloys are non-crystalline. Materials in which such a disordered structure is produced directly from the liquid state during cooling are sometimes referred to as “glasses.” Accordingly, amorphous metals are commonly referred to as “metallic glasses” or “glassy metals.” In one embodiment, a bulk metallic glass (“BMG”) can refer to an alloy, of which the microstructure is at least partially amorphous. However, there are several ways besides extremely rapid cooling to produce amorphous metals, including physical vapor deposition, solid-state reaction, ion irradiation, melt spinning, and mechanical alloying. Amorphous alloys can be a single class of materials, regardless of how they are prepared.
Amorphous metals can be produced through a variety of quick-cooling methods. For instance, amorphous metals can be produced by sputtering molten metal onto a spinning metal disk. The rapid cooling, on the order of millions of degrees a second, can be too fast for crystals to form, and the material is thus “locked in” a glassy state. Also, amorphous metals/alloys can be produced with critical cooling rates low enough to allow formation of amorphous structures in thick layers—e.g., bulk metallic glasses.
The terms “bulk metallic glass” (“BMG”), bulk amorphous alloy (“BAA”), and bulk solidifying amorphous alloy are used interchangeably herein. They refer to amorphous alloys having the smallest dimension at least in the millimeter range. For example, the dimension can be at least about 0.5 mm, such as at least about 1 mm, such as at least about 2 mm, such as at least about 4 mm, such as at least about 5 mm, such as at least about 6 mm, such as at least about 8 mm, such as at least about 10 mm, such as at least about 12 mm. Depending on the geometry, the dimension can refer to the diameter, radius, thickness, width, length, etc. A BMG can also be a metallic glass having at least one dimension in the centimeter range, such as at least about 1.0 cm, such as at least about 2.0 cm, such as at least about 5.0 cm, such as at least about 10.0 cm. In some embodiments, a BMG can have at least one dimension at least in the meter range. A BMG can take any of the shapes or forms described above, as related to a metallic glass. Accordingly, a BMG described herein in some embodiments can be different from a thin film made by a conventional deposition technique in one important aspect—the former can be of a much larger dimension than the latter.
Amorphous metals can be an alloy rather than a pure metal. The alloys may contain atoms of significantly different sizes, leading to low free volume (and therefore having viscosity up to orders of magnitude higher than other metals and alloys) in a molten state. The viscosity prevents the atoms from moving enough to form an ordered lattice. The material structure may result in low shrinkage during cooling and resistance to plastic deformation. The absence of grain boundaries, the weak spots of crystalline materials in some cases, may, for example, lead to better resistance to wear and corrosion. In one embodiment, amorphous metals, while technically glasses, may also be much tougher and less brittle than oxide glasses and ceramics.
Thermal conductivity of amorphous materials may be lower than that of their crystalline counterparts. To achieve formation of an amorphous structure even during slower cooling, the alloy may be made of three or more components, leading to complex crystal units with higher potential energy and lower probability of formation. The formation of amorphous alloy can depend on several factors: the composition of the components of the alloy; the atomic radius of the components (preferably with a significant difference of over 12% to achieve high packing density and low free volume); and the negative heat of mixing the combination of components, inhibiting crystal nucleation and prolonging the time the molten metal stays in a supercooled state. However, as the formation of an amorphous alloy is based on many different variables, it can be difficult to make a prior determination of whether an alloy composition would form an amorphous alloy.
Amorphous alloys, for example, of boron, silicon, phosphorus, and other glass formers with magnetic metals (iron, cobalt, nickel) may be magnetic, with low coercivity and high electrical resistance. The high resistance leads to low losses by eddy currents when subjected to alternating magnetic fields, a property useful, for example, as transformer magnetic cores.
Amorphous alloys may have a variety of potentially useful properties. In particular, they tend to be stronger than crystalline alloys of similar chemical composition, and they can sustain larger reversible (“elastic”) deformations than crystalline alloys. Amorphous metals derive their strength directly from their non-crystalline structure, which can have none of the defects (such as dislocations) that limit the strength of crystalline alloys. For example, one modern amorphous metal, known as Vitreloy™, has a tensile strength that is almost twice that of high-grade titanium. In some embodiments, metallic glasses at room temperature are not ductile and tend to fail suddenly when loaded in tension, which limits the material applicability in reliability-critical applications, as the impending failure is not evident. Therefore, to overcome this challenge, metal matrix composite materials having a metallic glass matrix containing dendritic particles or fibers of a ductile crystalline metal can be used. Alternatively, a BMG low in element(s) that tend to cause embitterment (e.g., Ni) can be used. For example, a Ni-free BMG can be used to improve the ductility of the BMG.
Another useful property of bulk amorphous alloys is that they can be true glasses; in other words, they can soften and flow upon heating. This can allow for easy processing, such as by injection molding, in much the same way as polymers. As a result, amorphous alloys can be used for making sports equipment, medical devices, electronic components and equipment, and thin films. Thin films of amorphous metals can be deposited as protective coatings via a high velocity oxygen fuel technique.
A material can have an amorphous phase, a crystalline phase, or both. The amorphous and crystalline phases can have the same chemical composition and differ only in the microstructure—i.e., one amorphous and the other crystalline. Microstructure in one embodiment refers to the structure of a material as revealed by a microscope at 25× magnification or higher. Alternatively, the two phases can have different chemical compositions and microstructures. For example, a composition can be partially amorphous, substantially amorphous, or completely amorphous.
As described above, the degree of amorphicity (and conversely the degree of crystallinity) can be measured by fraction of crystals present in the alloy. The degree can refer to volume fraction of weight fraction of the crystalline phase present in the alloy. A partially amorphous composition can refer to a composition of at least about 5 vol % of which is of an amorphous phase, such as at least about 10 vol %, such as at least about 20 vol %, such as at least about 40 vol %, such as at least about 60 vol %, such as at least about 80 vol %, such as at least about 90 vol %. The terms “substantially” and “about” have been defined elsewhere in this application. Accordingly, a composition that is at least substantially amorphous can refer to one of which at least about 90 vol % is amorphous, such as at least about 95 vol %, such as at least about 98 vol %, such as at least about 99 vol %, such as at least about 99.5 vol %, such as at least about 99.8 vol %, such as at least about 99.9 vol %. In one embodiment, a substantially amorphous composition can have some incidental, insignificant amount of crystalline phase present therein.
In one embodiment, an amorphous alloy composition can be homogeneous with respect to the amorphous phase. A substance that is uniform in composition is homogeneous. This is in contrast to a substance that is heterogeneous. The term “composition” refers to the chemical composition and/or microstructure in the substance. A substance is homogeneous when a volume of the substance is divided in half and both halves have substantially the same composition. For example, a particulate suspension is homogeneous when a volume of the particulate suspension is divided in half and both halves have substantially the same volume of particles. However, it might be possible to see the individual particles under a microscope. Another example of a homogeneous substance is air where different ingredients therein are equally suspended, though the particles, gases and liquids in air can be analyzed separately or separated from air.
A composition that is homogeneous with respect to an amorphous alloy can refer to one having an amorphous phase substantially uniformly distributed throughout its microstructure. In other words, the composition macroscopically includes a substantially uniformly distributed amorphous alloy throughout the composition. In an alternative embodiment, the composition can be of a composite, having an amorphous phase having therein a non-amorphous phase. The non-amorphous phase can be a crystal or a plurality of crystals. The crystals can be in the form of particulates of any shape, such as spherical, ellipsoid, wire-like, rod-like, sheet-like, flake-like, or an irregular shape. In one embodiment, it can have a dendritic form. For example, an at least partially amorphous composite composition can have a crystalline phase in the shape of dendrites dispersed in an amorphous phase matrix; the dispersion can be uniform or non-uniform, and the amorphous phase and the crystalline phase can have the same or a different chemical composition. In one embodiment, they have substantially the same chemical composition. In another embodiment, the crystalline phase can be more ductile than the BMG phase.
The methods described herein can be applicable to any type of amorphous alloy. Similarly, the amorphous alloy described herein as a constituent of a composition or article can be of any type. The amorphous alloy can include the element Zr, Hf, Ti, Cu, Ni, Pt, Pd, Fe, Mg, Au, La, Ag, Al, Mo, Nb, Be, or combinations thereof. Namely, the alloy can include any combination of these elements in its chemical formula or chemical composition. The elements can be present at different weight or volume percentages. For example, an iron “based” alloy can refer to an alloy having a non-insignificant weight percentage of iron present therein, the weight percent can be, for example, at least about 20 wt %, such as at least about 40 wt %, such as at least about 50 wt %, such as at least about 60 wt %, such as at least about 80 wt %. Alternatively, in one embodiment, the above-described percentages can be volume percentages, instead of weight percentages. Accordingly, an amorphous alloy can be zirconium-based, titanium-based, platinum-based, palladium-based, gold-based, silver-based, copper-based, iron-based, nickel-based, aluminum-based, molybdenum-based, and the like. The alloy can also be free of any of the aforementioned elements to suit a particular purpose. For example, in some embodiments, the alloy, or the composition including the alloy, can be substantially free of nickel, aluminum, titanium, beryllium, or combinations thereof. In one embodiment, the alloy or the composite is completely free of nickel, aluminum, titanium, beryllium, or combinations thereof.
For example, the amorphous alloy can have the formula (Zr, Ti)a(Ni, Cu, Fe)b(Be, Al, Si, B)c, wherein a, b, and c each represents a weight or atomic percentage. In one embodiment, a is in the range of from 30 to 75, b is in the range of from 5 to 60, and c is in the range of from 0 to 50 in atomic percentages. Alternatively, the amorphous alloy can have the formula (Zr, Ti)a(Ni, Cu)b(Be)c, wherein a, b, and c each represents a weight or atomic percentage. In one embodiment, a is in the range of from 40 to 75, b is in the range of from 5 to 50, and c is in the range of from 5 to 50 in atomic percentages. The alloy can also have the formula (Zr, Ti)b(Ni, Cu)b(Be)c, wherein a, b, and c each represents a weight or atomic percentage. In one embodiment, a is in the range of from 45 to 65, b is in the range of from 7.5 to 35, and c is in the range of from 10 to 37.5 in atomic percentages. Alternatively, the alloy can have the formula (Zr)a(Nb, Ti)b(Ni, Cu)c(Al)d, wherein a, b, c, and d each represents a weight or atomic percentage. In one embodiment, a is in the range of from 45 to 65, b is in the range of from 0 to 10, c is in the range of from 20 to 40 and d is in the range of from 7.5 to 15 in atomic percentages. One exemplary embodiment of the aforedescribed alloy system is a Zr—Ti—Ni—Cu—Be based amorphous alloy under the trade name Vitreloy™, such as Vitreloy-1 and Vitreloy-101, as fabricated by Liquidmetal Technologies, CA, USA. Some examples of amorphous alloys of the different systems are provided in Table 1 and Table 2.
Other exemplary ferrous metal-based alloys include compositions such as those disclosed in U.S. Patent Application Publication Nos. 2007/0079907 and 2008/0305387. These compositions include the Fe(Mn, Co, Ni, Cu) (C, Si, B, P, Al) system, wherein the Fe content is from 60 to 75 atomic percentage, the total of (Mn, Co, Ni, Cu) is in the range of from 5 to 25 atomic percentage, and the total of (C, Si, B, P, Al) is in the range of from 8 to 20 atomic percentage, as well as the exemplary composition Fe48Cr15Mo14Y2C15B6. They also include the alloy systems described by Fe—Cr—Mo—(Y,Ln)-C—B, Co—Cr—Mo-Ln-C—B, Fe—Mn—Cr—Mo—(Y,Ln)-C—B, (Fe, Cr, Co)—(Mo,Mn)—(C,B)—Y, Fe—(Co,Ni)—(Zr,Nb,Ta)—(Mo,W)—B, Fe—(Al,Ga)—(P,C,B,Si,Ge), Fe—(Co, Cr,Mo,Ga,Sb)—P—B—C, (Fe, Co)—B—Si—Nb alloys, and Fe—(Cr—Mo)—(C,B)—Tm, where Ln denotes a lanthanide element and Tm denotes a transition metal element. Furthermore, the amorphous alloy can also be one of the exemplary compositions Fe80P12.5C5B2.5, Fe80P11C5B2.5Si1.5, Fe74.5Mo5.5P12.5C5B2.5, Fe74.5Mo5.5P11C5B2.5Si1.5, Fe70Mo5Ni5P12.5C5B2.5, Fe70Mo5Ni5P11C5B2.5Si1.5, Fe68Mo5Ni5Cr2P12.5C5B2.5, and Fe68Mo5Ni5Cr2P11C5B2.5Si1.5, described in U.S. Patent Application Publication No. 2010/0300148.
The amorphous alloys can also be ferrous alloys, such as (Fe, Ni, Co) based alloys. Examples of such compositions are disclosed in U.S. Pat. Nos. 6,325,868; 5,288,344; 5,368,659; 5,618,359; and 5,735,975, Inoue et al., Appl. Phys. Lett., Volume 71, p 464 (1997), Shen et al., Mater. Trans., JIM, Volume 42, p 2136 (2001), and Japanese Patent Application No. 200126277 (Pub. No. 2001303218 A). One exemplary composition is Fe72Al5Ga2P11C6B4. Another example is Fe72Al7Zr10Mo5W2B15. Another iron-based alloy system that can be used in the coating herein is disclosed in U.S. Patent Application Publication No. 2010/0084052, wherein the amorphous metal contains, for example, manganese (1 to 3 atomic %), yttrium (0.1 to 10 atomic %), and silicon (0.3 to 3.1 atomic %) in the range of composition given in parentheses; and that contains the following elements in the specified range of composition given in parentheses: chromium (15 to 20 atomic %), molybdenum (2 to 15 atomic %), tungsten (1 to 3 atomic %), boron (5 to 16 atomic %), carbon (3 to 16 atomic %), and the balance iron.
The amorphous alloy can also be one of the Pt— or Pd— based alloys described by U.S. Patent Application Publication Nos. 2008/0135136, 2009/0162629, and 2010/0230012. Exemplary compositions include Pd44.48Cu32.35Co4.05P19.11, Pd77.5Ag6Si9P7.5, and Pt74.7Cu1.5Ag0.3P18B4Si1.5.
The aforedescribed amorphous alloy systems can further include additional elements, such as additional transition metal elements, including Nb, Cr, V, and Co. The additional elements can be present at less than or equal to about 30 wt %, such as less than or equal to about 20 wt %, such as less than or equal to about 10 wt %, such as less than or equal to about 5 wt %. In one embodiment, the additional, optional element is at least one of cobalt, manganese, zirconium, tantalum, niobium, tungsten, yttrium, titanium, vanadium and hafnium to form carbides and further improve wear and corrosion resistance. Further optional elements may include phosphorous, germanium and arsenic, totaling up to about 2%, and preferably less than 1%, to reduce melting point. Otherwise incidental impurities should be less than about 2% and preferably 0.5%.
In some embodiments, a composition having an amorphous alloy can include a small amount of impurities. The impurity elements can be intentionally added to modify the properties of the composition, such as improving the mechanical properties (e.g., hardness, strength, fracture mechanism, etc.) and/or improving the corrosion resistance. Alternatively, the impurities can be present as inevitable, incidental impurities, such as those obtained as a byproduct of processing and manufacturing. The impurities can be less than or equal to about 10 wt %, such as about 5 wt %, such as about 2 wt %, such as about 1 wt %, such as about 0.5 wt %, such as about 0.1 wt %. In some embodiments, these percentages can be volume percentages instead of weight percentages. In one embodiment, the alloy sample/composition consists essentially of the amorphous alloy (with only a small incidental amount of impurities). In another embodiment, the composition includes the amorphous alloy (with no observable trace of impurities).
In one embodiment, the final parts exceeded the critical casting thickness of the bulk solidifying amorphous alloys.
In embodiments herein, the existence of a supercooled liquid region in which the bulk-solidifying amorphous alloy can exist as a high viscous liquid allows for superplastic forming. Large plastic deformations can be obtained. The ability to undergo large plastic deformation in the supercooled liquid region is used for the forming and/or cutting process. As oppose to solids, the liquid bulk solidifying alloy deforms locally which drastically lowers the required energy for cutting and forming. The ease of cutting and forming depends on the temperature of the alloy, the mold, and the cutting tool. As higher is the temperature, the lower is the viscosity, and consequently easier is the cutting and forming.
Embodiments herein can utilize a thermoplastic-forming process with amorphous alloys carried out between Tg and Tx, for example. Herein, Tx and Tg are determined from standard DSC measurements at typical heating rates (e.g. 20° C./min) as the onset of crystallization temperature and the onset of glass transition temperature.
The amorphous alloy components can have the critical casting thickness and the final part can have thickness that is thicker than the critical casting thickness. Moreover, the time and temperature of the heating and shaping operation is selected such that the elastic strain limit of the amorphous alloy could be substantially preserved to be not less than 1.0%, and preferably not being less than 1.5%. In the context of the embodiments herein, temperatures around glass transition means the forming temperatures can be below glass transition, at or around glass transition, and above glass transition temperature, but preferably at temperatures below the crystallization temperature TX. The cooling step is carried out at rates similar to the heating rates at the heating step, and preferably at rates greater than the heating rates at the heating step. The cooling step is also achieved preferably while the forming and shaping loads are still maintained.
The embodiments herein can be valuable in the fabrication of electronic devices using a BMG. An electronic device herein can refer to any electronic device known in the art. For example, it can be a telephone, such as a cell phone, and a land-line phone, or any communication device, such as a smart phone, including, for example an iPhone™, and an electronic email sending/receiving device. It can be a part of a display, such as a digital display, a TV monitor, an electronic-book reader, a portable web-browser (e.g., iPad™), and a computer monitor. It can also be an entertainment device, including a portable DVD player, conventional DVD player, Blu-Ray disk player, video game console, music player, such as a portable music player (e.g., iPod™), etc. It can also be a part of a device that provides control, such as controlling the streaming of images, videos, sounds (e.g., Apple TV™), or it can be a remote control for an electronic device. It can be a part of a computer or its accessories, such as the hard drive tower housing or casing, laptop housing, laptop keyboard, laptop track pad, desktop keyboard, mouse, and speaker. The article can also be applied to a device such as a watch or a clock.
As previously noted, molten amorphous alloys like Vitreloy™ by Liquidmetal Technologies, are non-Newtonian fluids, meaning that under strain, the viscosity decreases. Ultrasonic vibrations increase the strain at multiple points throughout the fluid during the injection cycle. Ultrasonic vibrations also break the surface tension.
According to embodiments herein, an injection molding or die casting machine has an associated ultrasonic vibration generator that is configured to apply ultrasonic vibrations during melting and/or injection of the molten material (e.g., molten alloy). The ultrasonic vibrations may be applied to molten material via the plunger tip of the plunger in the injection molding or die casting machine, and/or the mold and/or the vessel, for example. The ultrasonic vibration may be applied during plunger tip movement so that the molten material vibrates ultrasonically during melting and injection. A connector may be connected to the ultrasonic vibration generator and the plunger. Channels may be provided in the plunger tip and/or vessel to accommodate a cooling fluid during melting and injection.
In accordance with various embodiments, there is provided a plunger of an injection molding or die casting machine. The plunger has a plunger body and a plunger tip associated with the plunger body. The plunger tip has an end surface configured to directly contact a molten material used in injection molding in the injection molding or die casting machine. Also provided is a connector that is connected to an ultrasonic vibration generator that is associated with the injection molding or die casting machine. At least the end surface of the plunger tip is configured to vibrate at ultrasonic vibrations applied via the ultrasonic vibration generator and through the connector during injection of the molten material.
In accordance with various embodiments, there is provided an injection molding or die casting machine comprising an ultrasonic vibration generator that is configured to apply ultrasonic vibrations during melting and injection of the molten material.
In accordance with various embodiments, there is provided a method. The method is a method of injection molding a meltable material in an injection molding or die casting machine comprising a plunger, an ultrasonic transducer, a vessel configured to receive the meltable material for melting therein; and a mold for molding the molten material, wherein the plunger comprises a plunger body and a plunger tip configured to directly contact a molten material in the vessel and move the molten material from the vessel and to inject the molten material into the mold, and wherein the ultrasonic transducer is configured to apply ultrasonic vibrations to at least the plunger tip. The method includes: applying ultrasonic vibrations to at least the plunger tip of the plunger via the ultrasonic transducer; melting the meltable material into a molten state in the vessel; and forcing the molten material from the vessel and into the mold using the plunger. At least the plunger tip applies ultrasonic vibrations to the material during both the melting and the forcing of the material.
Also, in accordance with embodiments, the material for melting comprises a BMG feedstock, and a BMG part may be formed.
The methods, techniques, and devices illustrated herein are not intended to be limited to the illustrated embodiments. As disclosed herein, an apparatus or a system (or a device or a machine) is configured to perform melting of and injection molding of material(s) (such as amorphous alloys). The apparatus is configured to process such materials or alloys by melting at higher melting temperatures before injecting the molten material into a mold for molding. As further described below, parts of the apparatus are positioned in-line with each other. In accordance with some embodiments, parts of the apparatus (or access thereto) are aligned on a horizontal axis. The following embodiments are for illustrative purposes only and are not meant to be limiting.
In injection molding and die casting, alloy(s) in a molten state is/are injected into a mold. Two issues may sometimes occur during the process. One is the lack of thermal homogeneity of the molten alloy. A second is the surface quality and filling characteristics of the alloy as it flows into the mold, e.g., the molten alloy may freeze or crystallize as it fills the mold. The former may be improved by this disclosure because of the stirring effect of the ultrasonic vibrations. The latter may be improved by this disclosure because of improved shear thinning effects. That is, the melt or molten alloy flows more smoothly when ultrasonic vibrations are applied to at least the plunger tip of the plunger as disclosed herein, resulting in a slip stick effect, where ultrasonic vibrations are transmitted through the material rather than it sticking onto a surface or surfaces of the machine. Accordingly, freezing or crystallizing of the molten alloy during filling of the mold can be substantially reduced and/or substantially prevented by implementing the device and method of this disclosure. Further, defects such as surface defects, film works, gloss, etc. can be reduced or eliminated.
Application of ultrasonic vibrations increases the strain at multiple points throughout a molten alloy during the injection cycle. Ultrasonic vibrations may also break the surface tension. As disclosed herein, the application of ultrasonic vibrations to a molten material or alloy by an ultrasonic generation device (e.g., transducer) associated with an injection molding or die casting machine improves the implementation process and the resultant molded product. Accordingly, this disclosure allows the molten alloy to flow faster into the mold (improving both fill and quality as the temperature gradient is crucial for the formation of a bulk metallic glass) in a machine, flow into smaller and sharper parts of the mold (typical filling radii are reduced), and prevent knit lines (a major surface defect that arises from two flow fronts from meeting) from forming, by allowing the flow fronts to mix. This disclosure also may be used to remove bubbles from the molten alloy (during melting and filling), and reduce shrinkage porosity. Further, utilizing vibrations as disclosed herein allows for improved and/or better contact of the molten material or alloy with the mold, resulting in an improved finished surface with less defects and less knit lines. Boundary effects and surface tensions effects in a cavity of a mold may also be improved by applying vibrations as disclosed herein.
These and other embodiments are discussed below with reference to
The injection molding or die casting machine 300 also has an ultrasonic vibration generator device 352 that is configured to apply ultrasonic vibrations to one or more parts of the machine 300 during melting and injection of the molten material 305. As understood by one of ordinary skill in the art, ultrasonic vibrations includes vibrations of frequencies greater than the upper limit of the audible range for humans—that is, greater than about 20 kilohertz (kHz).
In an embodiment, the range of ultrasonic vibrations for selection of an applied frequency (or frequencies) is about 20 kHz up to about several gigahertz. In one embodiment, the range of ultrasonic vibrations is about 20 kHz up to about 500 MHz (megahertz). In another embodiment, the range of ultrasonic vibrations is about 20 kHz up to about 200 MHz. In another embodiment, the range of ultrasonic vibrations is above about 200 MHz. In yet another embodiment, the range of ultrasonic vibrations is above about 2 MHz. In still yet another embodiment, the range of ultrasonic vibrations is about 20 kHz up to about 2 MHz. In one embodiment, the range of ultrasonic vibrations is about 20 kHz up to about 1 MHz.
The ultrasonic vibration generator 352 may include or comprise an ultrasonic transducer. An ultrasonic transducer is a device used to convert some other type of energy into an ultrasonic vibration. Ultrasonic vibrations may be created electronically, mechanically, magnetically, or piezoelectrically. Accordingly, the ultrasonic vibration generator device 352 may include a mechanical transducer, an electromechanical transducer, a magnetostrictive transducer, or a piezoelectric transducer.
In accordance with an embodiment, the ultrasonic vibration generator 352 is connected to the plunger 330. For example, in one embodiment, as noted in greater detail below, at least a plunger tip 334 is configured for ultrasonic vibration and movement relative to its plunger body. The ultrasonic vibration generator 352 may be connected to the plunger 330 via a connector 354 (further described below).
In an embodiment, the ultrasonic vibration generator is further and/or alternatively connected to the mold 340 and is configured to apply ultrasonic vibrations to the molten material 305 during injection into the mold 340. The ultrasonic vibration generator 352 may be connected to the mold 340 via a connector 362.
In an embodiment, the ultrasonic vibration generator is further and/or alternatively connected to the vessel 312 and is configured to apply ultrasonic vibrations to the meltable material during melting of the meltable material by the heat source 320. The ultrasonic vibration generator 352 may be connected to the vessel 312 via a connector 356.
In an embodiment, the ultrasonic vibration generator is further and/or alternatively connected to a portion of the melt zone 310, e.g., the heat source 320, and is configured to apply ultrasonic vibrations to the meltable material during melting of the meltable material by the heat source 320. The ultrasonic vibration generator 352 may be connected to the melt zone 310 and/or heat source 320 via a connector 358.
In an embodiment, the plunger tip 334 is removeably connected to the plunger body. For example, the plunger tip 334 may be connected to the plunger body by screw thread. In an embodiment, an end surface of the plunger body may be separated from the plunger tip 334 by a gap.
In an embodiment, the plunger 330 comprises a connector 354 that is connected to the ultrasonic vibration generator 352 associated with the injection molding or die casting machine 300. The connector 354 is schematically shown in
In an embodiment, at least the end surface of the plunger tip 334 is configured to vibrate at ultrasonic vibrations applied via the ultrasonic vibration generator 352 and through the connector 354 during injection of the molten material 305 into the mold 340.
The connector 354 may be an electronic connector, and the ultrasonic vibration generator 352 may be configured to create ultrasonic vibrations electronically. The connector 354 may be a mechanical connector, and the ultrasonic vibration generator 352 may be configured to create ultrasonic vibrations mechanically. The connector 354 may be a magnetic connector, and the ultrasonic vibration generator 352 may be configured to create ultrasonic vibrations magnetically. The connector 354 may be an electric connector, and the ultrasonic vibration generator may be configured to create ultrasonic vibrations piezoelectrically.
The plunger body is configured not to be in direct contact with the molten material during an injection molding cycle. The plunger tip 334 is configured to be in direct contact with the molten material during the injection molding cycle.
In an embodiment, the plunger 330 is temperature regulated. Because of the application of heat from the heat source, its proximity to the heat source, and contact with molten material, the plunger 330 or parts thereof are subject to melting. As such, tempering or cooling of the plunger 330 allows for its utilization before, during, and after melting of meltable material without damaging its body. In an injection molding machine, for example, the plunger often directly contacts the molten material and thus is exposed to high temperature. The plunger may be cooled by running coolant through channels in the plunger. The plunger 330 may include one or more channels 331 or cooling lines therein configured to accommodate a flow a gas, a fluid, or a liquid (e.g., water, oil, or other fluid) therein for regulating a temperature of the body and/or tip 334 of plunger 330 during, for example, melting of material in the vessel (e.g., to force cool the plunger 330). The channel(s) 331 assist in preventing excessive heating and melting of the body and/or tip 334 of the plunger 330 itself during application of the induction field (e.g., from the heat source 320). The channel(s) 331 may be connected to a cooling system 360 configured to induce flow of a gas or a liquid in the plunger 330. The channel(s) 316 may include one or more inlets and outlets for the fluid to flow there-through. The channel(s) 316 may be configured in any number of ways and are not meant to be limited. The number, positioning, shape, and/or direction of the channel(s) 331 should not be limited. The activation or application of cooling fluid through the channel(s) 331 is also not limited. The cooling liquid or fluid or gas from the cooling system 360 may be configured to flow through the channel(s) 331 during melting of the meltable material, after melting of the meltable material, when heat source 320 is powered, during a period of time power is supplied to the heat source, during movement of the molten material 305 towards and/or into the mold 340, or at any interval desired or necessary to regulate the temperature of the plunger 330 to a desired (e.g., lesser) temperature.
Melt zone 310 includes a melting mechanism configured to receive meltable material and to hold the material as it is heated to a molten state. The melting mechanism may be in the form of a vessel 312, for example, that has a body for receiving meltable material and configured to melt the material therein. Vessel 312 may have an inlet for inputting material (e.g., feedstock) into a receiving or melting portion 314 of its body. The body of the vessel has a length and can extend in a longitudinal and horizontal direction, as shown in
A vessel as used throughout this disclosure is a container or body made of a material employed for heating substances to high temperatures. The vessel also acts as, or may be, a shot sleeve for moving molten material towards a mold. It should be understood that the terms “shot sleeve” and “vessel” may be used interchangeably throughout this disclosure with reference to a device for receiving meltable material (e.g., BMG) and containing such material during melting when a heat source or field is applied to melt the meltable material. The device can allow for movement of the molten material after a melting process into a mold. Additionally, the vessel 312 may be an induction field concentrator. That is, vessel 312 may be designed and configured to locally concentrate a magnetic field (e.g., a secondary field resulting from induction source 320) to promote a reaction and thus melting of a material provided within the vessel 312.
In an embodiment, vessel 312 is a cold hearth melting device that is configured to be utilized for meltable material(s) while under a vacuum (e.g., applied by a vacuum device 336 or pump at a vacuum port).
In an embodiment, a body of the vessel and/or its melting portion 314 may include substantially rounded and/or smooth surfaces. For example, a surface of melting portion 314 may be formed in an arcuate, a round, or a circular shape. However, the shape and/or surfaces of the body are not meant to be limiting. The body may be an integral structure, or formed from separate parts that are joined or machined together.
The body of vessel 312 is configured to receive the plunger 330 therethrough in a horizontal direction to move the molten material. That is, in an embodiment, the melting mechanism is on the same axis as the plunger 330, and the body of the vessel or shot sleeve can be configured and/or sized to receive at least part of the plunger, e.g., the plunger tip 334, to substantially cover or enclose [at least the tip 334 of] the plunger 330 as it moves into and through the body (in either direction). Thus, plunger 330 can be configured to move molten material (during and/or after heating/melting) from the vessel by moving substantially through vessel 312, and pushing or forcing molten material into a mold 340. Referencing the illustrated embodiment of machine 300 in
To heat melt zone 310 and melt the meltable material received in vessel 312, machine 300 also includes a heat source that is used to heat and melt the meltable material. At least melting portion 314 of the vessel, if not substantially the entire body itself, is configured to be heated such that the material received therein is melted. Heating is accomplished using, for example, an induction source 320 positioned within melt zone 310 that is configured to melt the meltable material. In an embodiment, induction source 320 is positioned adjacent vessel 312. For example, induction source 320 may be in the form of a coil positioned in a helical manner substantially around a length of the vessel body. However, other configurations or patterns that are configured to melt material within the vessel 312 can be used. As such, vessel 312 may be configured to inductively melt a meltable material (e.g., an inserted ingot of metal alloy) within melting portion 314 by supplying a magnetic field to the meltable material resulting from power being applied heat source 320, using a power supply or source. Thus, the melt zone 310 can include an induction zone. Induction coil 320 is configured to heat up and melt any material that is contained by vessel 312 without melting and wetting vessel 312. Induction coil 320 emits radiofrequency (RF) waves towards vessel 312 which generates a magnetic field for melting the material therein. As shown, the body and coil 320 surrounding vessel 312 may be configured for positioning in a horizontal direction along a horizontal axis (e.g., X axis). In an embodiment, the induction coil 320 is positioned in a horizontal configuration such that its turns are positioned around and adjacent the vessel 312.
In an embodiment, the vessel 312 is a temperature regulated vessel. Because there are eddy currents (second magnetic field) circulating in the inner bore/inner surfaces of the vessel during application of an induction field, the body of the vessel itself is subject to melting. As such, tempering or cooling of the vessel 312 allows for its utilization before, during, and after melting of meltable material without damaging its body. Such a vessel 312 may include one or more temperature regulating channels 316 or cooling lines configured to flow a gas, a fluid, or a liquid (e.g., water, oil, or other fluid) therein for regulating a temperature of the body of vessel 312 during, for example, melting of material in the vessel (e.g., to force cool the vessel). Such a force-cooled vessel can also be provided on the same axis as the plunger 330. The channel(s) 316 assist in preventing excessive heating and melting of the body of the vessel 312 itself during application of the induction field (e.g., from induction coil 320). Regulating channel(s) 316 may be connected to a cooling system 360 configured to induce flow of a gas or a liquid in the vessel. The regulating channel(s) 316 may include one or more inlets and outlets for the fluid to flow there-through. An inlet and an outlet can be connected to one or more of the temperature regulating channels design to flow the fluid in, through, and out of the body. The inlets and outlets of the channels 316 may be configured in any number of ways and are not meant to be limited. For example, channel(s) 316 may be positioned relative to melting portion 314 such that material thereon is melted and the vessel temperature is regulated (i.e., heat is absorbed, and the vessel is cooled). Regulating channel(s) can be provided within the body of the vessel between an inner surface of its inner bore and its outer surface, and/or extending between a first end and a second end of its body. The number, positioning, shape, and/or direction of the regulating channel(s) should not be limited. The activation or application of cooling fluid through the channel(s) is also not limited. The cooling liquid or fluid may be configured to flow through the regulating channel(s) during melting of the meltable material, after melting of the meltable material, when induction source 320 is powered, during a period of time power is supplied to the induction source, during application of the induction field, when the heat source (induction source) 320 is off, or at any interval desired or necessary to regulate the temperature of the vessel to a desired (e.g., lesser) regulated temperature. Channels may be considered input channels and output channels. The number of input channels in the vessel can, but need not be, the same as the number of output channels.
The regulating channel(s) 316 may include one or more inlets and outlets for the liquid or fluid to flow into, therethrough, and out of the vessel. The inlets and outlets of the regulating channels may be configured in any number of ways and are not meant to be limited. Further, a direction of flow of fluid or liquid within the channel(s) is not limiting. For example, in an embodiment, the fluid may be configured to enter and exit each channel such that the liquid flows in one direction. In another embodiment, the liquid may be configured to flow in alternate directions, e.g., each adjacent line may include an alternating entrance and exit. The fluid or liquid can be configured to flow into one or more inlets, and then longitudinally along a first side of the body, for example, and flow longitudinally along a second side of the body in an opposite direction, in each of the channels 316, and out of one or more outlets. The direction of flow within each channel need not be the same. In addition, the regulating channels may be configured to have one or more entrances/exits that are configured to allow flow of the liquid between the channels. For example, in an embodiment wherein a vessel includes longitudinally extending regulating channels, one or more of the channels may include one or more lateral or extending line(s) that extend to another channel(s) or line(s) such that they are fluidly joined to each other. That is, the liquid can be configured to not only run longitudinally along the body, but also through and between connected channel(s).
The number, shape, positioning, flow within, and/or direction of the regulating channel(s) 316 in the vessel and/or the channel(s) 331 in the plunger as shown in
The meltable material can be received in the melt zone 310 in any number of forms. For example, the meltable material may be provided into the melt zone in the form of an ingot (solid state), a semi-solid state, a slurry that is preheated, powder, pellets, etc. In some embodiments, a loading port not shown) may be provided as part of the machine 300. The loading port can be a separate opening or area that is provided within the machine at any number of places.
The method of melting and molding material can be performed using a machine 300 having features such as those disclosed with reference to
To perform the method of molding the molten material, the machine 300 may be configured to inject material into a mold 340 in a substantially horizontal direction by moving its plunger 330 in a longitudinal and/or horizontal direction, for example. The plunger 330 may be configured to push a material for melting into the body, optionally hold material during the melting process within the vessel and the melt zone, and/or move the melted material from the melting portion 314, in a substantially horizontal direction, by traveling through the vessel 312 (e.g., from right to left, towards the mold 340). The vessel 312 is configured to accommodate movement of the tip 334 and body of the plunger 330 as it is moved and extended therethrough.
In accordance with an embodiment, after the material is melted in the vessel 312, plunger 330 may be used to force the molten material from the vessel 312 and into a mold 340 for molding into an object, a part or a piece. In instances wherein the meltable material is an alloy, such as an amorphous alloy, the mold 340 is configured to form a molded bulk amorphous alloy object, part, or piece. Mold 340 has an inlet for receiving molten material there-through. An output of the vessel 312 (e.g., second or back end that is used for injection) and an inlet of the mold 340 can be provided in-line and on a horizontal axis such that plunger 330 is moved in a horizontal direction through body of the vessel 312 to inject molten material into the mold 340 via its inlet.
Ultrasonic vibrations may be applied to the molten material during melting and/or during movement/injecting of the molten material 305 into the mold 340. In an embodiment, at least the plunger tip 334 applies ultrasonic vibrations to the material 305 during both the melting and the forcing of the material. The method may include only applying ultrasonic vibrations to the molten material 305 during the forcing of the molten material 305 into the mold 340. The method may include only applying ultrasonic vibrations to the meltable material 305 during the melting into a molten state.
Cooling fluid may flow through the channel(s) 331 of the plunger 330 and/or the channel(s) 316 of the shot sleeve 312 to regulate a temperature of the vessel 312 during the melting of the meltable material by flowing the cooling fluid therein and regulate a temperature of the plunger 330 by flowing the cooling fluid therein.
In an embodiment, the method includes stopping the applying of the ultrasonic vibrations by the ultrasonic vibration generation device 352, and ejecting molded material from the mold 340 (e.g., using the plunger 330).
The sequence of events during the injection mold of a part is called the injection molding cycle. The cycle begins when the mold closes, followed by the injection of the molten material into the mold. Once the mold is filled, a holding pressure is maintained to compensate for any material shrinkage. Once the part is sufficiently cool, the mold opens and the part is ejected.
As previously noted, systems such as machine 300 that are used to mold materials such as metals or alloys may implement a vacuum when forcing molten material into a mold or die cavity. The machine 300 can further include at least one vacuum source 336 or pump operatively connected thereto that is configured to apply vacuum pressure to at least vessel 312 in the melt zone 310 and to mold 340 via vacuum ports 332 and 333, shown in
In an embodiment, mold 340 is a vacuum mold that is an enclosed structure configured to regulate vacuum pressure therein when molding materials. For example, in an embodiment, vacuum mold 340 includes a first plate (also referred to as an “A” mold or “A” plate), a second plate (also referred to as a “B” mold or “B” plate) positioned adjacently (respectively) with respect to each other. The first plate and second plate generally each have a mold cavity associated therewith for molding melted material there-between. The mold cavities may include a part cavity for forming and molding a part, such as a BMG part, therein.
In an embodiment, the cavities of the mold 340 are configured to mold molten material received there-between via an optional injection sleeve or transfer sleeve 350 from the melt zone. Generally, the first plate of mold 340 may be connected to transfer sleeve 350. Transfer sleeve 350 (sometimes referred to as a shot sleeve, a cold sleeve or an injection sleeve in the art and herein) may be provided between melt zone 310 and mold 340. Transfer sleeve 350 has an opening that is configured to receive and allow transfer of the molten material there-through and into mold 340 (using plunger 330). Its opening may be provided in a horizontal direction along the horizontal axis (e.g., X axis). The transfer sleeve need not be a cold chamber. In an embodiment, at least plunger 330, vessel 312 (e.g., inner wall of its receiving or melting portion), and opening of the transfer sleeve 350 are provided in-line and on a horizontal axis, such that plunger 330 can be moved in a horizontal direction through the body of the vessel 312 in order to move the molten material from the vessel 312 and into (and subsequently through) the opening of transfer sleeve 350, and into mold 340. Transfer sleeve 350 may also be under vacuum pressure and/or enclosed in a vacuum chamber during melting and molding processes.
Molten material is pushed in a horizontal direction through transfer sleeve 350 and into the mold cavity(ies) via the inlet (e.g., in a first plate) and between the first and second plates. During molding of the material, the at least first and second plates are configured to substantially eliminate exposure of the material (e.g., amorphous alloy) there-between, e.g., to oxygen and nitrogen. Specifically, a vacuum is applied such that atmospheric air is substantially eliminated from within the plates and their cavities. A vacuum pressure is applied to an inside of vacuum mold 340 using at least one vacuum source that is connected via vacuum lines and ports 332 and 333. For example, the vacuum pressure or level on the system can be held between 1×10−1 to 1×104 Torr during the melting and subsequent molding cycle. In another embodiment, the vacuum level is maintained between 1×10−2 to about 1×10−4 Torr during the melting and molding process. Of course, other pressure levels or ranges may be used, such as 1×10−9 Torr to about 1×10−3 Torr, and/or 1×10−3 Torr to about 0.1 Torr. An ejector mechanism (not shown) is configured to eject molded (amorphous alloy) material (or the molded part) from the mold cavity between the first and second plates of mold 340. The ejection mechanism is associated with or connected to an actuation mechanism (not shown) that is configured to be actuated in order to eject the molded material or part (e.g., after first and second parts and are moved horizontally and relatively away from each other, after vacuum pressure between at least the plates is released).
Any number or types of molds may be employed in the machine 300. For example, any number of plates may be provided between and/or adjacent the first and second plates to form the mold. Molds known in the art as “A” series, “B” series, and/or “X” series molds, for example, may be implemented in the system/machine 300. The mold may be made from metal, such as steel or aluminum, and precision-machined to form the features of the desired part.
The mold can be cooled by passing a coolant (usually water) through a series of holes drilled through the mold plates and connected by hoses to form a continuous pathway. The coolant absorbs heat from the mold (which has absorbed heat from the molten material in the mold) and keeps the mold at a proper temperature to solidify the molten material.
A uniform heating of the material to be melted and maintenance of temperature of molten material in such a machine 300 assists in forming a uniform molded part. For explanatory purposes only, throughout this disclosure material to be melted is described and illustrated as being in the form of an ingot that is in the form of a solid state feedstock; however, it should be noted that the material to be melted may be received in system or machine 300 in a solid state, a semi-solid state, a slurry that is preheated, powder, pellets, etc., and that the form of the material is not limiting.
It should be noted that the body of vessel 312 in any of the embodiments disclosed herein may be formed from any number of materials (e.g., copper, silver), include one or more coatings or layers on any of the surfaces or parts thereof, and/or configurations or designs. For example, one or more surfaces may have recesses or grooves therein. The material(s) used to form a vessel body, the material(s) to be melted, and layer(s) of material are not meant to be limiting.
The body of the vessel 312 may be formed from or include one or more materials, including a combination of materials or alloys. For example, the vessel 312 may comprise a metal or a combination of metals, such as one selected from the group of: stainless steel (SS), copper, copper beryllium, copper chrome, amcolloy, sialon ceramic, yttria, zirconia, chrome, titanium, and stabilized ceramic coating. In an embodiment, vessel 312 is formed from a copper alloy. In an embodiment, the vessel 312 is formed from, or has coated thereon, one or more materials that are RF insensitive.
In an embodiment, one or more coatings or layers on one or more surfaces or parts of the vessel 312 are thermal insulators thermal barriers, or electrical conductors. For example, a coating can be applied to an inner sleeve of the vessel 312 using a plating technique. The coating(s) or layer(s) on surfaces or parts need not be consistent; that is, the area of application of a coating or layering material is not limited to covering an entire surface or limited to a particular thickness or pattern. Any number and/or types of methods may be used for applying a coating material to the vessel 312 and should not be limiting. In an embodiment, a coating or layer material may comprise at least one of the following group: ceramic, quartz, stainless steel, titanium, chrome, copper, silver, gold, diamond-like carbon, yttria, yttria oxide, and zirconia. Deposition of these types of materials can provide surface hardness and wear resistance while at the same time remain conductive for efficient heat transfer. Application of a coating with enhanced electrical conductivity to the disclosed vessel can increase the density of the eddy currents in the boat, and thereby increase the field strength inside the boat.
Similarly, the plunger 330 and/or its tip 334 may be formed from any number of materials and/or include one or more coatings or layers on its surfaces and/or in its channel(s) 331.
In an embodiment, the vibration generator device may be configured to apply ultrasonic vibrations at different frequencies depending on the in the method or part of the cycle. For example, ultrasonic vibrations may be applied at a first frequency during melting of a material, and ultrasonic vibrations may be applied at a second frequency that is different than the first frequency during filling of the material and/or injection of the molten material into the mold.
In one embodiment, the frequency at which ultrasonic vibrations are applied is dependent upon the part in the apparatus or system. For example, ultrasonic vibrations may be applied at a first frequency to the plunger tip, and ultrasonic vibrations at a second frequency that is different than the first frequency may be applied to the mold.
In yet another embodiment, the frequency of the ultrasonic vibrations may be tuned during the process or method. For example, the ultrasonic vibrations may be applied at a first frequency when molten alloy is first injected into a cavity of a mold, and then gradually adjusted (e.g., increased) as the cavity is filled (e.g., increased during the entire filling process, or increased upon a certain percentage being filled). In an embodiment, the application of ultrasonic vibrations may be tuned for the entire filling cycle or filling process.
Accordingly, this disclosure describes embodiments of applying ultrasonic vibrations to one or more parts of an injection molding or die casting device via an ultrasonic generation device, to improve the melting and/or molding processes of molten alloys.
Although not described in great detail, the disclosed injection system may include additional parts including, but not limited to, one or more sensors, e.g., temperature sensor, flow meters, etc. (e.g., to monitor temperature, cooling water flow, etc.), and/or one or more controllers. The material to be molded (and/or melted) using any of the embodiments of the injection system as disclosed herein may include any number of materials and should not be limited. In one embodiment, the material to be molded is an amorphous alloy, as described above.
In an embodiment, the type of vibrations applied to one or more parts of an injection molding or die casting device (e.g., a plunger) and the device used to apply such vibrations are based on a type of mold that is used. For example, the type of vibrations can be tuned for an individual mold.
The presently described apparatus and methods can be used to form various parts or articles, which can be used, for example, for Yankee dryer rolls; automotive and diesel engine piston rings; pump components such as shafts, sleeves, seals, impellers, casing areas, plungers; Wankel engine components such as housing, end plate; and machine elements such as cylinder liners, pistons, valve stems and hydraulic rams. In embodiments, apparatus and methods can be used to form housings or other parts of an electronic device, such as, for example, a part of the housing or casing of the device or an electrical interconnector thereof. The apparatus and methods can also be used to manufacture portions of any consumer electronic device, such as cell phones, desktop computers, laptop computers, and/or portable music players. As used herein, an “electronic device” can refer to any electronic device, such as consumer electronic device. For example, it can be a telephone, such as a cell phone, and/or a land-line phone, or any communication device, such as a smart phone, including, for example an iPhone™, and an electronic email sending/receiving device. It can be a part of a display, such as a digital display, a TV monitor, an electronic-book reader, a portable web-browser (e.g., iPad™), and a computer monitor. It can also be an entertainment device, including a portable DVD player, DVD player, Blu-Ray disk player, video game console, music player, such as a portable music player (e.g., iPod™), etc. It can also be a part of a device that provides control, such as controlling the streaming of images, videos, sounds (e.g., Apple TV™), or it can be a remote control for an electronic device. It can be a part of a computer or its accessories, such as the hard driver tower housing or casing, laptop housing, laptop keyboard, laptop track pad, desktop keyboard, mouse, and speaker. The coating can also be applied to a device such as a watch or a clock.
While the invention is described and illustrated here in the context of a limited number of embodiments, the invention may be embodied in many forms without departing from the spirit of the essential characteristics of the invention. The illustrated and described embodiments, including what is described in the abstract of the disclosure, are therefore to be considered in all respects as illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.
The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not target to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.
This application claims priority to U.S. Provisional Patent Application No. 62/005,539, filed May 30, 2014, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62005539 | May 2014 | US |
