Patent Application
20210053155
The subject matter relates to joining of heterogeneous materials, and more particularly, to a connecting article, a method for manufacturing the connecting article, and a laser device.
Nonmetals include glass, ceramics, and plastics. Such nonmetallic material may be required to be joined to metallic material in various fields.
Glass has low toughness and low impact resistance, and joining glass and metal together increases the toughness and the impact resistance. However, since thermal expansion coefficients of glass and metal are quite different, thermal and residual stresses are generated at an interface of glass and metal, often creating a fatal weakness.
Furthermore, the poor surface wettability of glass also increases the difficulty in joining, the same thing also happens between ceramics and metal.
The connection of plastic and metal is relatively easy. However, low manufacturing cost and high connecting strength between plastic and metal seem to be mutually exclusive. Therefore, there is room for improvement in the art.
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous components. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.
The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the like.
The bonding layer 40 is formed by disposing the first alloy 30 and a composite layer 20 on the non-metallic body 10, and then melting the first alloy 30, at least a portion of the composite layer 20, and at least a portion of the non-metallic body 10 by a laser treatment. The composite layer 20 includes the second alloy 22 and an oxide layer 24 disposed on the second alloy 22.
Non-metal mean non-metallic materials, such as ceramics and plastics, having better surface wettability than glasses. When the non-metallic body 10 is made of glass, the composite layer 20 improves the connecting strength between the glass and the first alloy 30. Specifically, when the first alloy 30 is melted to form a liquid alloy, a surface tension between the liquid alloy and the composite layer 20 is less than a surface tension between the liquid alloy and the non-metallic body 10 when the composite layer 20 is absent. Thus, the composite layer 20 improves the surface wettability of the non-metallic body 10, thereby improving the connecting strength between the non-metallic body 10 and the first alloy 30.
The second alloy 22 may be at least one of iron-based alloy, aluminum-based alloy, titanium-based alloy, and nickel-based alloy. Referring to
In an embodiment, the second alloy 22 is iron-based alloy. The oxide layer 24 is iron oxide, such as ferrous oxide (FeO), ferric oxide (Fe2O3), tetra Ferric oxide (Fe3O4), a mixture of FeO and Fe3O4, or a mixture of Fe3O4 and Fe2O3. The composition of the oxide layer 24 also affects the surface wettability of the non-metallic body 10 and the first alloy 30. The oxide layer 24 being made of a mixture of iron oxides has a greater influence on the connecting strength between the non-metallic body 10 and the first alloy 30 than the oxide layer 24 being made of a single iron oxide. When the oxide layer 24 is made of a mixture of iron oxides, the connecting strength between the non-metallic body 10 and the first alloy 30 is greater.
In addition, the amount of the iron oxide in the oxide layer 24 also affects the surface wettability of the non-metallic body 10. For example, the lower the amount of Fe3O4 and the higher the amount of Fe2O3 in the oxide layer 24, the better the surface wettability of the non-metallic body 10.
The thickness of the composite layer 20 is in a range from 40 μm to 80 μm. If the thickness of the composite layer 20 is lower than 40 the strength of the composite layer 20 is insufficient. If the thickness of the composite layer 20 is over 80 μm, the laser energy cannot reach the non-metallic body 10, and the first alloy 30 cannot react with the composite layer 20 and the first alloy 30.
In an embodiment, the thickness of the oxide layer 24 is in a range from 2 μm to 10 μm. The thickness of the oxide layer 24 also affects the connecting strength of the non-metallic body 10 and the first alloy 30. When the thickness of the oxide layer 24 is increased, the connecting strength of the non-metallic body 10 and the first alloy 30 first increases but then gradually decreases. In an embodiment, the oxide layer 24 having the thickness of 2 μm to 10 μm significantly increases the connecting strength of the non-metallic body 10 and the first alloy 30.
In other embodiments, the device 200 may further include a metal element (not shown) disposed on the bonding layer 40 of the connecting article 100. The metal element may be formed on the bonding layer 40 by 3D printing. The metal element and the bonding layer 40 may be made of materials having similar physical and chemical properties.
The first controller 410 can control the surface treatment device 420 to change the processing procedure, thereby controlling the thickness of the composite layer 20 within the range from 40 μm to 80 μm. For example, the thickness of the composite layer 20 can be controlled to be 40 μm, 60 μm, or 80 μm.
Furthermore, the surface treatment device 420 can be at least one of a vacuum coating device, a magnetic particle sputtering device, a thermal spraying device, and a cold spraying device.
The first controller 410 can control the heat treatment furnace 430 to change the heating temperature and heating period, thereby controlling the thickness of the oxide layer 24 within the range from 2 μm to 10 μm. For example, the thickness of the oxide layer 24 can be controlled to be 2 μm, 6 μm, 8 μm, or 10 μm.
The laser device 300 further includes a cavity (not shown), a beam expander 330, and a scanner 340. The cavity can receive an object. The beam expander 330 is connected to the laser source 320, and can adjust a diameter and a divergence angle of the laser beams 50 from the laser source 320. The scanner 340 is connected to the beam expander 330, and can apply the laser beams 50 from the beam expander 330 onto the object, thereby treating the surface of the object. In the embodiment, the laser source 320 is a fiber laser source. The object to be processed is the non-metallic body 10 containing the composite layer 20 and the first alloy 30.
The second controller 310 stores information as to a set of light emission paths. The second controller 310 can control the laser beams 50 to be emitted through at least one light emission path in the set. In an embodiment, the set of light emission paths includes a first light emission path and a second light emission path.
Furthermore, the set of light emission paths includes a first light emission path and a second light emission path, and an angle θ between the second light emission path and the first light emission path is in a range from 40 degrees to 80 degrees.
At block S1, referring to
At block S2, referring to
At block S3, referring to
In an embodiment, the first alloy 30 has high purity, high sphericity or quasi-sphericity degree, small particle size, good powder flowability, and good powder spreadability. The high sphericity increases the powder flowability and the powder spreadability, which improves the uniformity of density of the connecting article 100, thereby ensuring the quality of the connecting article 100.
Furthermore, the particle size of the first alloy 30 is in a range from 15 μm to 53 μm. The first alloy 30 with a small particle size has a larger specific surface area, absorbing more laser energy under the laser treatment and being easily melted. Moreover, the first alloy 30 with a small particle size is more uniformly distributed on the composite layer 20, ensuring the quality of the connecting article 100. When the first alloy 30 has a small particle size, gaps between the powders are also small, and a high packing density is obtained. Thus, the connecting article 100 has a high density, which improves the strength and the surface quality of the connecting article 100. However, when the particle size of the first alloy 30 is too small, the powders of the first alloy 30 tend to adhere to each other, decreasing the powder flowability of the first alloy 30. Thus, uneven powder spreadability is the result, which affects the quality of the connecting article 100.
In an embodiment, the first alloy 30 includes powders of at least two particle sizes, that is, fine powders (for example, having a particle size of 25 μm) and coarse powders (for example, having a particle size of 40 μm) mixed in a certain ratio. Thus, the first alloy 30 combines advantages of both of the fine powders and coarse powders. The particle sizes of the fine powders and the coarse powders, and the ratio of mix can be varied according to actual need.
At block S4, referring to
Referring to
Furthermore, by controlling the energy density of the laser beams 50 through the second controller 310, the depth and the width of the molten pool 60 can be controlled. In an embodiment, the power of the laser source 320 is in a range from 160 W to 220 W. The scanning speed of the laser beams 50 is in a range from 800 mm/s to 1200 mm/s. The depth of the molten pool 60 is in a range from 0.1 mm to 0.4 mm.
The entire melting and solidification process may be completed in a very short time. The laser spot has high power density, which causes the target spot on the surface of the object to rapidly increase in temperature. The structure and the viscosity of the non-metallic body 10 are also rapidly changed. After the laser treatment, the temperature decreases, and the molten material rapidly solidifies. The rapid heating and solidification reduce residual stress at the connecting interface.
In an embodiment, the non-metallic body 10 is silicate glass. The second alloy 22 is iron-based alloy. The first alloy 30 is stainless steel. When irradiated by the laser beams 50 in an inert gas (such as argon) atmosphere, the silicon and oxygen elements in the silicate glass, and the iron element in the composite layer 20 and the first alloy 30, react to form a new phase Fe2SiO4, which is the key factor for tightly connecting the glass and the first alloy 30. Moreover, the surface composition of the glass changes under the laser treatment, for example, Na2O, SiO2, Al2O3, and other substances in the glass are significantly reduced. The carbon and iron elements in the first alloy 30 are oxidized. The physical and chemical properties of the glass and the first alloy 30 are quite different, but the composite layer 20 plays a key role in the connection between the composite layer 20 and the non-metallic body 10. By controlling the thickness and the composition of the composite layer 20, the connecting article 100 with a high quality can be obtained.
In an embodiment, block S3 and block S4 can be repeated a number of times (for example, 10 times to 20 times). That is, the first alloy 30 is disposed on the composite layer 20, and the SLM process is performed. Then, the first alloy 30 is again disposed on the composite layer 20 and another SLM process is performed. Finally, the first alloy 30, at least a portion of the composite layer 20, and at least a portion of the non-metallic body 10 are integrally connected.
Furthermore, the laser beams 50 can be emitted through at least one light emission path. Although only one light emission path is necessary for the laser melting process, excessive residual stress may be generated, and emitting the laser beams 50 through more than one light emission path reduces the residual stress.
Referring to
Then, referring to
The method improves the surface wettability of the non-metallic body 10 by providing the composite layer 20 on the non-metallic body 10 during the bonding process. The connecting strength between the non-metallic body 10 and the first alloy 30 can also be increased. The materials of the composite layer 20 and the first alloy 30 are not limited, so the bonding layer 40 can be formed on different metal elements. The method is simple, which can be applied in various production processes.
A glass containing a composite layer was provided. A first alloy having a particle size of 15 μm to 53 μm was laid on the composite layer. The first alloy, a portion of the composite layer, and a portion of the glass was melted and then solidified to for the connecting article.
The difference from Example 1 is that the particle size of the first alloy is 5 μm to 15 μm. Other blocks are the same of Example 1.
The difference from Example 1 is that the particle diameter of the first alloy is 53 μm to 100 μm. Other blocks are the same of Example 1.
The difference from Example 1 is that the particle size of the first alloy is greater than 100 μm. Other blocks are the same of Example 1.
Table 1 shows manufacturing parameters and properties of the connecting articles of Example 1 and Comparative Examples 1-3. The properties include powder flowability, powder spreadability, density tested by cross-sectional metallographic analysis, surface roughness, and molded surface quality.
From Table 1, making comparisons between powders of Comparative Example 1 being too small (particle size of 5 μm to 15 μm) and the powders of Comparative Example 2 (particle size of 53 μm to 100 μm) and Comparative Example 3 (particle size of more than 100 μm) being too large, the powders of Example 1 (particle size of 15 μm to 53 μm) have the best powder flowability and spreadability. By combining fine powders and coarse powders, gaps of the coarse powders are infilled by the fine powders, as in Example 1, so that the connecting article 100 has the highest density, the highest strength, and the best surface quality.
In addition, the connecting articles of Examples 2-21 were prepared. The qualities of the connecting articles of Examples 2-21 are controlled by changing the parameters of SLM process (that is, the laser power and laser scanning speed). The depth and the width of the molten pool were changed by changing the parameters of SLM process. Then, the properties of the connecting articles of Examples 2-21 were tested, and the test results were shown in Table 2. In Examples 2-21, the particle size of the first alloy was 15 μm to 53 μm. The power of the fiber laser source was 500 W. The laser power was 80 W to 240 W. The diameter of the laser spot was 80 mm to 120 mm. The laser scanning speed was 400 mm/s to 1600 mm/s. The inert atmosphere was argon gas.
Moreover, connecting articles of Examples 22-33 and Comparative Examples 4-7 were prepared. The qualities of the connecting articles of Examples 22-33 and Comparative Examples 4-7 were controlled by controlling the thicknesses of the second alloy and the oxide layer of the composite layer. The particle size of the first alloy was 15 μm to 53 μm. The first alloy was stainless steel. The thickness of the glass was 2.0 mm-3.0 mm. The power of the fiber laser source was 500 W. The laser power was 200 W. The diameter of the laser spot was 80 mm to 120 mm. The scanning speed was 1200 mm/s. The glass containing the composite layer and the first alloy was heated to 200 degrees Celsius. The inert atmosphere was argon gas, including oxygen content of less than 100 ppm. Under laser energy, the first alloy, a portion of the composite layer, and a portion of the glass are quickly melted and solidified to obtain the connecting article. The properties of the connecting articles were tested, and the tested results were shown in Table 3. Furthermore, the thickness of the composite layer 20 is almost equal to the thickness of the second alloy 22 plus the thickness of the oxide layer 24.
Even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present exemplary embodiments, to the full extent indicated by the plain meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201910785043.8 | Aug 2019 | CN | national |
