Alloy systems are generally categorized by the major element, i.e., the host element, such as iron, aluminum, nickel, and titanium, for instance, where one element is the major element, and the others are minor elements. For example, steels are mainly made of iron and aluminum alloys are mainly made of aluminum. Bronze consists primarily of copper and about 12% tin. Brass is a copper-based alloy having zinc.
Broadly, the present disclosure relates to metal powders, wires and other forms (e.g., elongated forms) having a variety of cross-sectional shapes, such as extruded tubes and bars, for use in additive manufacturing, welding, cladding and other metal deposition techniques, and multi-component alloy products made from such materials (e.g., by via additive manufacturing and/or welding). The composition(s) and/or physical properties of the metal powders or wires may be tailored. In turn, additive manufacturing may be used to produce tailored multi-alloy product materials.
As used herein, “multi-component alloy product” and the like means a product with a metal matrix, where at least four different elements make up the matrix, and where the multi-component product comprises 5-35 at. % of the at least four elements. In one embodiment, at least five different elements make up the matrix, and the multi-component product comprises 5-35 at. % of the at least five elements. In one embodiment, at least six different elements make up the matrix, and the multi-component product comprises 5-35 at. % of the at least six elements. In one embodiment, at least seven different elements make up the matrix, and the multi-component product comprises 5-35 at. % of the at least seven elements. In one embodiment, at least eight different elements make up the matrix, and the multi-component product comprises 5-35 at. % of the at least eight elements. As described below, additives may also be used relative to the matrix of the multi-component alloy product.
As noted above, the present disclosure relates to metal powders, wires and other forms (e.g., elongated forms) having a variety of cross-sectional shapes, such as extruded tubes and bars, for use in additive manufacturing, welding, cladding and other metal deposition techniques, and multi-component alloy products made from such materials (e.g., by via additive manufacturing and/or welding). The composition(s) and/or physical properties of the metal powders or wires may be tailored. In turn, additive manufacturing may be used to produce tailored multi-alloy product materials.
The new multi-component alloy (“MCA”) products are generally produced via a method that facilitates selective heating of powders or wires to temperatures above the liquidus temperature of the particular multi-component alloy product to be formed, thereby forming a molten pool followed by rapid solidification of the molten pool. The rapid solidification facilitates maintaining various alloying elements in solid solution. In one embodiment, the new multi-component alloy products are produced via additive manufacturing techniques. Additive manufacturing techniques facilitate the selective heating of powders or wires above the liquidus temperature of the particular multi-component alloy, thereby forming a molten pool followed by rapid solidification of the molten pool
As used herein, “additive manufacturing” means “a process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies”, as defined in ASTM F2792-12a entitled “Standard Terminology for Additively Manufacturing Technologies”. The multi-component alloy products described herein may be manufactured via any appropriate additive manufacturing technique described in this ASTM standard, such as binder jetting, directed energy deposition, material extrusion, material jetting, powder bed fusion, or sheet lamination, among others. In one embodiment, an additive manufacturing process includes depositing successive layers of one or more powders and then selectively melting and/or sintering the powders to create, layer-by-layer, a multi-component alloy product. In one embodiment, an additive manufacturing processes uses one or more of Selective Laser Sintering (SLS), Selective Laser Melting (SLM), and Electron Beam Melting (EBM), among others. In one embodiment, an additive manufacturing process uses an EOSINT M 280 Direct Metal Laser Sintering (DMLS) additive manufacturing system, or comparable system, available from EOS GmbH (Robert-Stirling-Ring 1, 82152 Krailling/Munich, Germany).
In one embodiment, a method comprises (a) dispersing a powder in a bed, (b) selectively heating a portion of the powder (e.g., via a laser) to a temperature above the liquidus temperature of the particular multi-component alloy product to be formed, (c) forming a molten pool and (d) cooling the molten pool at a cooling rate of at least 1000° C. per second. In one embodiment, the cooling rate is at least 10,000° C. per second. In another embodiment, the cooling rate is at least 100,000° C. per second. In another embodiment, the cooling rate is at least 1,000,000° C. per second. Steps (a)-(d) may be repeated as necessary until the multi-component alloy product is completed.
As used herein, “metal powder” means a material comprising a plurality of metal particles, optionally with some non-metal particles. The metal particles of the metal powder may be all the same type of metal particles, or may be a blend of metal particles, optionally with non-metal particles, as described below. The metal particles of the metal powder may have pre-selected physical properties and/or pre-selected composition(s), thereby facilitating production of tailored multi-component alloy products. The metal powders may be used in a metal powder bed to produce a tailored multi-component alloy product via additive manufacturing. Similarly, any non-metal particles of the metal powder may have pre-selected physical properties and/or pre-selected composition(s), thereby facilitating production of tailored multi-component alloy products. The non-metal powders may be used in a metal powder bed to produce a tailored multi-component alloy product via additive manufacturing
As used herein, “metal particle” means a particle comprising at least one metal. The metal particles may be one-metal particles, multiple metal particles, and metal-non-metal (M-NM) particles, as described below. The metal particles may be produced, for example, via gas atomization.
As used herein, a “particle” means a minute fragment of matter having a size suitable for use in the powder of the powder bed (e.g., a size of from 5 microns to 100 microns). Particles may be produced, for example, via gas atomization.
For purposes of the present patent application, a “metal” is one of the following elements: aluminum (Al), silicon (Si), lithium (Li), any useful element of the alkaline earth metals, any useful element of the transition metals, any useful element of the post-transition metals, and any useful element of the rare earth elements.
As used herein, useful elements of the alkaline earth metals are beryllium (Be), magnesium (Mg), calcium (Ca), and strontium (Sr).
As used herein, useful elements of the transition metals are any of the metals shown in Table 1, below.
As used herein, useful elements of the post-transition metals are any of the metals shown in Table 2, below.
As used herein, useful elements of the rare earth elements are scandium, yttrium and any of the fifteen lanthanides elements. The lanthanides are the fifteen metallic chemical elements with atomic numbers 57 through 71, from lanthanum through lutetium.
As used herein non-metal particles are particles essentially free of metals. As used herein “essentially free of metals” means that the particles do not include any metals, except as an impurity. Non-metal particles include, for example, boron nitride (BN) and boron carbine (BC) particles, carbon-based polymer particles (e.g., short or long chained hydrocarbons (branched or unbranched)), carbon nanotube particles, and graphene particles, among others. The non-metal materials may also be in non-particulate form to assist in production or finalization of the multi-component alloy product.
In one embodiment, at least some of the metal particles of the metal powder consists essentially of a single metal (“one-metal particles”). The one-metal particles may consist essentially of any one metal useful in producing a multi-component alloy, such as any of the metals defined above.
In another embodiment, at least some of the metal particles of the metal powder include multiple metals (“multiple-metal particles”). For instance, a multiple-metal particle may comprise two or more of any of the metals listed in the definition of metals, above.
In one embodiment, at least some of the metal particles of the metal powder are metal-nonmetal (M-NM) particles. Metal-nonmetal (M-NM) particles include at least one metal with at least one non-metal. Examples of non-metal elements include oxygen, carbon, nitrogen and boron. Examples of M-NM particles include metal oxide particles (e.g., Al2O3), metal carbide particles (e.g., TiC, SiC), metal nitride particles (e.g., Si3N4), metal borides (e.g., TiB2), and combinations thereof
The metal particles and/or the non-metal particles of the metal powder may have tailored physical properties. For example, the particle size, the particle size distribution of the powder, and/or the shape of the particles may be pre-selected. In one embodiment, one or more physical properties of at least some of the particles are tailored in order to control at least one of the density (e.g., bulk density and/or tap density), the flowability of the metal powder, and/or the percent void volume of the metal powder bed (e.g., the percent porosity of the metal powder bed). For example, by adjusting the particle size distribution of the particles, voids in the powder bed may be restricted, thereby decreasing the percent void volume of the powder bed. In turn, multi-component alloy products having an actual density close to the theoretical density may be produced. In this regard, the metal powder may comprise a blend of powders having different size distributions. For example, the metal powder may comprise a blend of a first metal powder having a first particle size distribution and a second metal powder having a second particle size distribution, wherein the first and second particle size distributions are different. The metal powder may further comprise a third metal powder having a third particle size distribution, a fourth metal powder having a fourth particle size distribution, and so on. Thus, size distribution characteristics such as median particle size, average particle size, and standard deviation of particle size, among others, may be tailored via the blending of different metal powders having different particle size distributions. In one embodiment, a final multi-component alloy product realizes a density within 98% of the product's theoretical density. In another embodiment, a final multi-component alloy product realizes a density within 98.5% of the product's theoretical density. In yet another embodiment, a final multi-component alloy product realizes a density within 99.0% of the product's theoretical density. In another embodiment, a final multi-component alloy product realizes a density within 99.5% of the product's theoretical density. In yet another embodiment, a final multi-component alloy product realizes a density within 99.7%, or higher, of the product's theoretical density.
The metal powder may comprise any combination of one-metal particles, multiple-metal particles, M-NM particles and/or non-metal particles to produce the tailored multi-component alloy product, and, optionally, with any pre-selected physical property. For example, the metal powder may comprise a blend of a first type of metal particle with a second type of particle (metal or non-metal), wherein the first type of metal particle is a different type than the second type (compositionally different, physically different or both). The metal powder may further comprise a third type of particle (metal or non-metal), a fourth type of particle (metal or non-metal), and so on. As described in further detail below, the metal powder may be the same metal powder throughout the additive manufacturing of the multi-component alloy product, or the metal powder may be varied during the additive manufacturing process.
As noted above, additive manufacturing may be used to create, layer-by-layer, a multi-component alloy product. In one embodiment, a metal powder bed is used to create a multi-component alloy product (e.g., a tailored multi-component alloy product). As used herein a “metal powder bed” means a bed comprising a metal powder. During additive manufacturing, particles of different compositions may melt (e.g., rapidly melt) and then solidify (e.g., in the absence of homogenous mixing). Thus, multi-component alloy products having a homogenous or non-homogeneous microstructure may be produced.
One approach for producing a tailored additively manufactured product using a metal powder bed arrangement is illustrated in
Powder spreader (160) is connected to a control system (not shown) and is operable to move from the powder reservoir (121) to the build reservoir (151), thereby supplying preselected amount(s) of powder feedstock (122) to the build reservoir (151). The powder feedstock (122) may be a multi-component alloy feedstock, and may include at least four different elements (e.g., metals), where each of the at least four different elements make-up 5-35 at. % of the powder feedstock. In the illustrated embodiment, the powder spreader (160) is a roller and is configured to roll along a distribution surface (140) of the system to gather a preselected volume (128) of powder feedstock (122) and move this preselected volume (128) of powder feedstock (122) to the build reservoir (151) (e.g., by pushing/rolling the powder feedstock). For instance, platform (123) may be moved to the appropriate vertical position, wherein a preselected volume (128) of the powder feedstock (122) lies above the distribution surface (140). Correspondingly, the build platform (153) of the build space (110) may be lowered to accommodate the a preselected volume (128) of the powder feedstock (122). As powder spreader (160) moves from an entrance side (the left-hand side in
After the powder spreader (160) has distributed the gathered volume of powder (128) to the build reservoir (151), the powder spreader (160) may then be moved away from the build reservoir (151), such as to a neutral position, or a position upstream (to the left of in
Upon conclusion of the adhesive spraying step, the build platform (153) may be lowered, the powder supply platform (123) may be raised, and the process repeated, with multiple gathered volumes (128) being serially provided to the build reservoir (151) via powder spreader (160), until a multi-layer, tailored 3-D multi-component alloy part (150) is completed. As needed, a heater (not illustrated) may be used between one or more spray operations to cure (e.g., partially cure) any powder sprayed with adhesive. The final tailored 3-D multi-component alloy part may then be removed from the build space (110), wherein excess powder (152) (not having being substantively sprayed by the adhesive) is removed, leaving only the final “green” tailored 3-D multi-component alloy part (150). The final green tailored 3-D multi-component alloy part (150) may then be heated in a furnace or other suitable heating apparatus, thereby sintering the part and/or removing volatile component(s) (e.g., from the adhesive supply) from the part. In one embodiment, the final tailored 3-D multi-component alloy part (150) comprises a homogenous or near homogenous distribution of the metal powder feedstock (e.g., as shown in
As described above, the powder spreader (160) may move the gathered volume (128) of metal powder feedstock (122) to the build reservoir (151) via distribution surface (140). In another embodiment, at least one of the build space (110) and the powder supply (120) are operable to move in the lateral direction (e.g., in the X-direction) such that one or more outer surfaces of the build space (110) and powder supply (120) are in contact. In turn, powder spreader (160) may move the preselected volume (128) of the metal powder feedstock (122) to the build reservoir (151) directly and in the absence of any intervening surfaces between the build reservoir (151) and the powder reservoir (121).
As noted, the powder supply (120) includes an adjustable device (124) which is adjustable (via a control system, not shown) to move the platform (123) up and down within the powder reservoir (151). In one embodiment, the adjustable device (124) is in the form of a screw or other suitable mechanical apparatus. In another embodiment, the adjustable device (124) is a hydraulic device. Likewise, the adjustable device (154) of the build space may be a mechanical apparatus (e.g., a screw) or a hydraulic device.
As noted above, the powder reservoir (121) includes a metal powder feedstock (122), wherein at least some metal is present. This powder feedstock (122) may include one-metal particles, multiple-metal particles, M-NM particles, non-metal particles, and combinations thereof, wherein at least one of the one-metal particles, multiple-metal particles, and/or M-NM particles is present. Thus, tailored 3-D multi-component alloy products may be produced. In one approach, the powder feedstock (122) includes a sufficient amount of the one-metal particles, multiple-metal particles, M-NM particles, non-metal particles, and combinations thereof to make a dispersion-strengthened multi-component alloy. In one embodiment, the dispersion-strengthened multi-component alloy is an oxide dispersion strengthened multi-component alloy (e.g., containing a sufficient amount of oxides to dispersion strengthen the multi-component alloy product, but generally not greater than 10 wt. % oxides). In this regard, the metal powder feedstock (122) may include M-O particles, where M is a metal and O is oxygen. Suitable M-O particles include Y2O3, Al2O3, TiO2, and La2O3, among others.
In one embodiment, the build space (110), includes a heating apparatus (not shown), which may intentionally heat one or more portions of the build reservoir (151) of the build space (110), or powders or lased objects contained therein. In one embodiment, the heating apparatus heats a bottom portion of the build reservoir (151). In another embodiment, the heating apparatus heats one or more side portions of the build reservoir (151). In another embodiment, the heating apparatus heats at least portions of the bottom and sides of the build reservoir (151). The heating apparatus may be useful, for instance, to control the cooling rate and/or relax residual stress(es) during cooling of the lased 3-D multi-component alloy part (150′). Thus, higher yields may be realized for some multi-component alloy products. In one embodiment, controlled heating and/or cooling are used to produce controlled local thermal gradients within one or more portions of the lased 3-D multi-component alloy part (150′). The controlled local thermal gradients may facilitate, for instance, tailored textures or tailored microstructures within the final lased 3-D multi-component alloy part (150′). The system of
In another approach, and referring now to
As another example, the first powder spreader (160a) may only partially provide the first feedstock (122a) to the build reservoir (151) specifically and intentionally leaving a gap. Subsequently, the second powder spreader (160b) may provide the second feedstock (122b) to the build reservoir (151), at least partially filling the gap. The laser (188) may be utilized at any suitable time(s) relative to these first and second rolling operations. In turn, multi-region 3-D multi-component alloy products may be produced with a first portion (400) being laterally adjacent to the second portion (500) (e.g., as shown in
The first and second powder feedstocks (122a, 122b) may have the same compositions (e.g., for speed/efficiency purposes), but generally have different compositions. In one approach, the first feedstock (122a) comprises a first composition blend and the second feedstock (122b) comprises a second composition blend, different than the first composition. At least one of the first and second powder feedstocks (122a, 122b) include a sufficient amount of metal to make a multi-powder blend, the multi-powder blend having at least four different elements, each of the at least four different elements making up 5-35 at. % of the MCA powder blend. Thus, tailored 3-D multi-component alloy products may be produced. Any combinations of first and second feedstocks (122a, 122b) can be used to produce tailored 3-D multi-component alloy products, such as any of the multi-component alloy products illustrated in
As with the approaches of
The system (201) of
A powder spreader 260 may be operable to move between (to and from) a first position (202a) and a second position (202b), the first position being upstream of the first powder supply (220-1), and the second position (202b) being downstream of either the last powder supply (220-n) or the build space (210). As powder spreader (260) moves from the first position (202a) towards the second position (202b), it will gather the appropriate volume of first feedstock (222-1) from the first powder supply (220-1), the appropriate volume of second feedstock (220-2) from the second powder supply (222-2), and so forth, thereby producing a gathered volume (228). The volumes and compositions of the first through final feedstocks (220-1 to 220-n) can be tailored and controlled for each rolling cycle to facilitate production of tailored 3-D multi-component alloy products, or portions thereof.
For instance, the first powder supply (220-1) may include a first metal powder (e.g., a one-metal powder) as its feedstock (222-1), and the second powder supply (220-2) may include a second metal powder (e.g., a multi-metal powder) as its feedstock (222-2). As powder spreader (260) moves from upstream of the first powder supply (220-1), along distribution surface (240), to downstream of the second powder supply (220-2), the powder spreader (260) may gather the first and second volumes of metal powders (222-1, 222-2), thereby producing a tailored powder blend (228) downstream of the second powder supply (220-2). As powder spreader (260) moves towards build reservoir (251), the first and second powders may mix (e.g., by tumbling, by applying vibration to upper surface (240), e.g., via optional vibratory apparatus 275), or by other mixing/stirring apparatus). Subsequent powder feedstocks (222-3 (not shown) to 222-n) may be utilized or avoided (e.g., by closing the top of the powder supply(ies)) as powder spreader (260) moves towards the second position (202b). Ultimately, a final powder feedstock (222=2221+2+ . . . N) may be provided for additive manufacturing, such as for use in powder bed build space (210). A laser (188) may then be used, as described above relative to
The flexibility of the system (201) facilitates the in-situ production of any of the products illustrated in
As an alternative, the system (201) may be controlled such that powder spreader (260) only gathers materials from the appropriate powder supplies (220-2 to 220-n) to produce the desired material layers. For instance, the powder spreader (260) may be controlled to avoid the appropriate powder supplies (e.g., moving non-linearly to avoid). As another example, the powder supplies (220-1 to 220-n) may include selectively operable lids or closures, such that the system (201) can remove any appropriate powder supplies (220-1 to 220-n) from communicating with the powder spreader (260) for any appropriate cycle by selectively closing such lids or closures.
The powder spreader (260) may be controlled via a suitable control system to move from the first position (202a) to the second position (202b), or any positions therebetween. For instance, after a cycle, the powder spreader (260) may return to a position downstream of the first powder supply (220-1), and upstream of the second powder supply (220-2) to facilitate gathering of the appropriate volume of the second feedstock (222-2), avoiding the first feedstock (222-1) altogether. Further, the powder spreader (260) may be moved in a linear or non-linear fashion, as appropriate to gather the appropriate amounts of the feedstocks (222-1 to 222-n) for the additive manufacturing operation. Also, multiple rollers can be used to move and/or blend the feedstocks (222-1 to 222-n). Finally, while more than two powder supplies (222-1 to 222-n) are illustrated in
The additive manufacturing apparatus and systems described in
As one specific example, and with reference now to
The final tailored multi-component alloy product may alternatively comprise at least two separately produced distinct regions. In one embodiment, different metal powder bed types may be used to produce a multi-component alloy product. For instance, a first metal powder bed may comprise a first metal powder and a second metal powder bed may comprise a second metal powder, different than the first metal powder. The first metal powder bed may be used to produce a first layer or portion of a multi-component alloy product, and the second metal powder bed may be used to produce a second layer or portion of the multi-component alloy product. For instance, and with reference now to
In one aspect, the first metal powder consists of one-metal particles. The first metal powder may be used in a first metal powder bed layer to produce a first region (400) of a tailored multi-component alloy body. Subsequently, a second metal powder may be used as a second metal powder bed layer to produce a second region (500) of a tailored multi-component alloy body (e.g., as per
In another aspect, the first metal powder consists of multiple-metal particles. The first metal powder may be used in a first metal powder bed layer to produce a first region (400) of a tailored multi-component alloy body. Subsequently, a second metal powder may be used as a second metal powder bed layer to produce a second region (500) of a tailored multi-component alloy body (e.g., as per
In another aspect, the first metal powder consists of M-NM particles. The first metal powder may be used in a first metal powder bed layer to produce a first region (400) of a tailored multi-component alloy body. Subsequently, a second metal powder may be used as a second metal powder bed layer to produce a second region (500) of a tailored multi-component alloy body (e.g., as per
In another aspect, the first metal powder consists of a mixture of one-metal particles and multiple-metal particles. The first metal powder may be used in a first metal powder bed layer to produce a first region (400) of a tailored multi-component alloy body. Subsequently, a second metal powder may be used as a second metal powder bed layer to produce a second region (500) of a tailored multi-component alloy body (e.g., as per
In another aspect, the first metal powder consists of a mixture of one-metal particles and M-NM particles. The first metal powder may be used in a first metal powder bed layer to produce a first region (400) of a tailored multi-component alloy body. Subsequently, a second metal powder may be used as a second metal powder bed layer to produce a second region (500) of a tailored multi-component alloy body (e.g., as per
In another aspect, the first metal powder consists of a mixture of one-metal particles, multiple-metal particles and M-NM particles. The first metal powder may be used in a first metal powder bed layer to produce a first region (400) of a tailored multi-component alloy body. Subsequently, a second metal powder may be used as a second metal powder bed layer to produce a second region (500) of a tailored multi-component alloy body (e.g., as per
In another aspect, the first metal powder consists of a mixture of multiple-metal particles and M-NM particles. The first metal powder may be used in a first metal powder bed layer to produce a first region (400) of a tailored multi-component alloy body. Subsequently, a second metal powder may be used as a second metal powder bed layer to produce a second region (500) of a tailored multi-component alloy body (e.g., as per
Thus, the systems and apparatus of
The powders used to in the additive manufacturing processes described herein may be produced by atomizing a material (e.g., an ingot) of the appropriate material into powders of the appropriate dimensions relative to the additive manufacturing process to be used.
After or during production, an additively manufactured product may be deformed (e.g., by one or more of rolling, extruding, forging, stretching, compressing). The final deformed product may realize, for instance, improved properties due to the tailored regions of the multi-component alloy product.
Referring now to
With continued reference to
The working step (30) generally involves hot working and/or cold working an intermediate product form. The hot working and/or cold working may include rolling, extrusion or forging of the material, for instance. The working (30) may occur before and/or after any dissolving step (20). For instance, after the conclusion of a dissolving step (20), the material may be allowed to cool to ambient temperature, and then reheated to an appropriate temperature for hot working. Alternatively, the material may be cold worked at around ambient temperatures. In some embodiments, the material may be hot worked, cooled to ambient, and then cold worked. In yet other embodiments, the hot working may commence after a soak of a dissolving step (20) so that reheating of the product is not required for hot working.
The working step (30) may result in precipitation of second phase particles. In this regard, any number of post-working dissolving steps (20) can be utilized, as appropriate, to dissolve at least some of the undissolved second phase particles that may have formed due to the working step (30).
After any appropriate dissolving (20) and working (30) steps, the final product form may be precipitation hardened (40). The precipitation hardening (40) may include heating the final product form above a solvus temperature for a time sufficient to dissolve at least some particles precipitated due to the working, and then rapidly cooling the final product form. The precipitation hardening (40) may further include subjecting the product to a target temperature for a time sufficient to form precipitates (e.g., strengthening precipitates), and then cooling the product to ambient temperature, thereby realizing a final aged product having desired precipitates therein. As may be appreciated, at least some working (30) of the product may be completed after a precipitating (40) step. In one embodiment, a final aged product contains ≧0.5 vol. % of the desired precipitates (e.g., strengthening precipitates) and ≦0.5 vol. % of coarse second phase particles.
In one approach, electron beam (EB) or plasma arc techniques are utilized to produce at least a portion of the additively manufactured multi-component alloy body. Electron beam techniques may facilitate production of larger parts than readily produced via laser additive manufacturing techniques. For instance, and with reference now to
In one embodiment, and referring now to
In another embodiment, and referring now to
In another embodiment, and referring now to
Another example of a wire useful in producing multi-component alloy products is shown in
In the instance of a monolithic wire, the monolith may have an origin in a plurality of different materials of different composition. In a first approach, an alloy formed with the desired weight composition of each element is cast and formed into a wire, like wire 900. In another embodiment, wire 900 may be composed of a solid core of a first material, upon which is deposited one or more outer layers, such as second and third portions 904, 906. The outer portions 904, 906 may be coated on the core, e.g., by dipping the core 902 in a melt of the second material and allowing the second material to solidify around the core 902 forming the second portion 904, followed by a similar process for enrobing the second portion 904 with a third portion 906 by dipping in a melt of the third material. Alternatively, the second and third portions can be joined to the core by chemical or physical processes, such as electroplating or spray deposition. In one embodiment, the second and/or third portions 904, 906 may be separately formed of a malleable sheet or strip that is then bent around the core 902 as indicated by the dotted lines 904D and 906D indicating conjoined ends, representing a mechanical approach for forming the wire 900. The materials of the portions 902, 904, 906, 908 can be in various physical forms. In one example, the core 902 may be formed of powdered metal or metal particles, such as shavings that are closely compressed by the second and third portions 904, 906. In another example, the core may be a solidified mass of metal particles and a flux compound. In another example, the core may be a solid metal filament or extrusion. While four portions 902, 904, 906, 908 are shown in
The material compositions for the wire(s) may be selected for utility in welding, cladding and/or additive manufacture. With respect to welding and cladding, the composition may be selected to join dissimilar materials by providing a multi-component alloy that is compatible with both. The wire 900 may be formed from a plurality of portions, e.g., 902, 904 of materials with different compositions. These portions, e.g., 902, 904 could be denominated “pre-alloys” that when combined under processing parameters achievable with the desired welding equipment will form, in situ, the desired multi-component alloy for use in welding, cladding or additive manufacturing. For example, a first pre-alloy material may be the core portion 902 of the wire 900 and the second pre-alloy material may be the outer portion 904. The number of portions 902, 904, 906, 908 can be varied to achieve a given percent composition for the multi-component alloy. In one embodiment, different physical portions, e.g., 902 and 906 may be of the same material composition and different from the material composition of another portion, e.g., 906, 908 in order to achieve the target percent composition of the multi-composition alloy within geometric constraints imposed by wire 900 dimensions.
In another embodiment, not illustrated, an electron beam (EB) or plasma arc additive manufacturing apparatus may employ multiple different wires with corresponding multiple different radiation sources, each of the wires and sources being fed and activated, as appropriate to provide the appropriate multi-component alloy product having a metal matrix, the metal matrix having at least four different elements making-up the matrix, and where the multi-component product comprises 5-35 at. % of the at least four elements.
In another approach, a method may comprise (a) selectively spraying one or more metal powders (as defined above) towards a building substrate, (b) heating, via a radiation source, the metal powders, and optionally the building substrate, above the liquidus temperature of the particular multi-component alloy product to be formed, thereby forming a molten pool, (c) cooling the molten pool, thereby forming a solid portion of the multi-component alloy product, wherein the cooling comprises cooling at a cooling rate of at least 100° C. per second. In one embodiment, the cooling rate is at least 1000° C. per second. In another embodiment, the cooling rate is at least 10,000° C. per second. The cooling step (c) may be accomplished by moving the radiation source away from the molten pool and/or by moving the building substrate having the molten pool away from the radiation source. Steps (a)-(c) may be repeated as necessary until the multi-component alloy product is completed. The spraying step (a) may be accomplished via one or more nozzles, and the composition of the metal powders can be varied, as appropriate, to provide tailored final multi-component alloy products having a metal matrix, the metal matrix having at least four different elements making-up the matrix, and where the multi-component product comprises 5-35 at. % of the at least four elements. The composition of the metal powder being heated at any one time can be varied in real-time by using different powders in different nozzles and/or by varying the powder composition(s) provided to any one nozzle in real-time. The work piece can be any suitable substrate. In one embodiment, the building substrate is, itself, a multi-component alloy product.
As noted above, welding may be used to produce multi-component alloy products. In one embodiment, the multi-component alloy product is produced by a melting operation applied to pre-cursor materials in the form of a plurality of metal components of different composition. The pre-cursor materials may be presented in juxtaposition relative to one another to allow simultaneous melting and mixing. In one example, the melting occurs in the course of electric arc welding, In another example, the melting may be conducted by a laser or an electron beam during additive manufacturing. The melting operation results in the plurality of metal components mixing in a molten state and forming a new alloy that is the multi-element product. The pre-cursor materials may be provided in the form of a plurality of physically separate forms, such as a plurality of elongated strands or fibers of metals or metal alloys of different composition or an elongated strand or a tube of a first composition and an adjacent powder of a second composition, e.g., contained within the tube or a strand having one or more clad layers. The pre-cursor materials may be formed into a structure, e.g., a twisted or braided cable or wire having multiple strands or fibers or a tube with an outer shell and a powder contained in the lumen thereof. The structure may then be handled to subject a portion thereof, e.g., a tip, to the melting operation, e.g., by using it as a welding electrode or as a feed stock for additive manufacturing. When so used, the structure and its component pre-cursor materials may be melted, e.g., in a continuous or discrete process to form a weld bead or a line or dots of material deposited for additive manufacture.
In one embodiment, the multi-component product is a weld body or filler interposed between and joined to a material or material to the welded, e.g., two bodies of the same or different material or a body of a single material with an aperture that the filler at least partially fills. In another embodiment, the filler exhibits a transition zone of changing composition relative to the material to which it is welded, such that the resultant combination could be considered the multi-component product.
While various embodiments of the new technology described herein have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the presently disclosed technology.
This patent application claims benefit of priority of U.S. Provisional Patent Application No. 62/336,920, filed May 16, 2016, and claims benefit of priority of U.S. Provisional Patent Application No. 62/385,887, filed Sep. 9, 2016, and claims benefit of priority of U.S. Provisional Patent Application No. 62/456,578, filed Feb. 8, 2017, each of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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62336920 | May 2016 | US | |
62385887 | Sep 2016 | US | |
62456578 | Feb 2017 | US |