CONNECTING ARTICLE AND METHOD FOR MANUFACTURING THE SAME, AND LASER DEVICE

A connecting article includes a non-metallic body and a bonding layer. The non-metallic body includes a non-metal. The bonding layer is bonded to the non-metallic body. The bonding layer includes the non-metal, a first alloy, and a second alloy. The present disclosure further provides a method for manufacturing the connecting article, and a laser device.

FIELD

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.

BACKGROUND

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.

DETAILED DESCRIPTION

FIGS. 4 and 5illustrate an embodiment of a connecting article100, which includes a non-metallic body10and a bonding layer40disposed on the non-metallic body10. The non-metallic body10includes a non-metal. The bonding layer40includes the non-metal, a first alloy30, and a second alloy22. The first alloy30and the second alloy22are different from each other.

The bonding layer40is formed by disposing the first alloy30and a composite layer20on the non-metallic body10, and then melting the first alloy30, at least a portion of the composite layer20, and at least a portion of the non-metallic body10by a laser treatment. The composite layer20includes the second alloy22and an oxide layer24disposed on the second alloy22.

Non-metal mean non-metallic materials, such as ceramics and plastics, having better surface wettability than glasses. When the non-metallic body10is made of glass, the composite layer20improves the connecting strength between the glass and the first alloy30. Specifically, when the first alloy30is melted to form a liquid alloy, a surface tension between the liquid alloy and the composite layer20is less than a surface tension between the liquid alloy and the non-metallic body10when the composite layer20is absent. Thus, the composite layer20improves the surface wettability of the non-metallic body10, thereby improving the connecting strength between the non-metallic body10and the first alloy30.

The second alloy22may be at least one of iron-based alloy, aluminum-based alloy, titanium-based alloy, and nickel-based alloy. Referring toFIG. 5, the oxide layer24is oxidized by a portion of the second alloy22. Specifically, the second alloy22is formed on the non-metallic body10through a metallization process. A portion of the second alloy22can be pre-oxidized to form the oxide layer24.

In an embodiment, the second alloy22is iron-based alloy. The oxide layer24is iron oxide, such as ferrous oxide (FeO), ferric oxide (Fe2O3), tetra Ferric oxide (Fe3O4), a mixture of FeO and Fe3O4, or a mixture of Fe3O4and Fe2O3. The composition of the oxide layer24also affects the surface wettability of the non-metallic body10and the first alloy30. The oxide layer24being made of a mixture of iron oxides has a greater influence on the connecting strength between the non-metallic body10and the first alloy30than the oxide layer24being made of a single iron oxide. When the oxide layer24is made of a mixture of iron oxides, the connecting strength between the non-metallic body10and the first alloy30is greater.

In addition, the amount of the iron oxide in the oxide layer24also affects the surface wettability of the non-metallic body10. For example, the lower the amount of Fe3O4and the higher the amount of Fe2O3in the oxide layer24, the better the surface wettability of the non-metallic body10.

The thickness of the composite layer20is in a range from 40 μm to 80 μm. If the thickness of the composite layer20is lower than 40 the strength of the composite layer20is insufficient. If the thickness of the composite layer20is over 80 μm, the laser energy cannot reach the non-metallic body10, and the first alloy30cannot react with the composite layer20and the first alloy30.

In an embodiment, the thickness of the oxide layer24is in a range from 2 μm to 10 μm. The thickness of the oxide layer24also affects the connecting strength of the non-metallic body10and the first alloy30. When the thickness of the oxide layer24is increased, the connecting strength of the non-metallic body10and the first alloy30first increases but then gradually decreases. In an embodiment, the oxide layer24having the thickness of 2 μm to 10 μm significantly increases the connecting strength of the non-metallic body10and the first alloy30.

FIG. 6illustrates an embodiment of a device200, which includes a body210and the connecting article100disposed on the body210. The device200may be an electronic device or a non-electronic device. The electronic device may include, but is not limited to, a mobile phone, a camera, and a computer. The non-electronic device may include, but is not limited to, a glass access control, a glass lamp, and a water glass.

In other embodiments, the device200may further include a metal element (not shown) disposed on the bonding layer40of the connecting article100. The metal element may be formed on the bonding layer40by3D printing. The metal element and the bonding layer40may be made of materials having similar physical and chemical properties.

FIG. 7illustrates an embodiment of a surface treatment equipment400. The surface treatment equipment400includes a surface treatment device420and a first controller410coupled to the surface treatment device420. The first controller410can control the surface treatment device420to perform a surface treatment on the non-metallic body10. In an embodiment, the non-metallic body10includes a surface12(shown inFIGS. 1-4). The first controller410controls the surface treatment device420to form the composite layer20on the surface12of the non-metallic body10.

The first controller410can control the surface treatment device420to change the processing procedure, thereby controlling the thickness of the composite layer20within the range from 40 μm to 80 μm. For example, the thickness of the composite layer20can be controlled to be 40 μm, 60 μm, or 80 μm.

Furthermore, the surface treatment device420can be at least one of a vacuum coating device, a magnetic particle sputtering device, a thermal spraying device, and a cold spraying device.

FIG. 8illustrates another embodiment of the surface treatment equipment400, which further includes a heat treatment furnace430coupled to the first controller410. The heat treatment furnace430oxidizes the composite layer20formed on the non-metallic body10.

The first controller410can control the heat treatment furnace430to change the heating temperature and heating period, thereby controlling the thickness of the oxide layer24within the range from 2 μm to 10 μm. For example, the thickness of the oxide layer24can be controlled to be 2 μm, 6 μm, 8 μm, or 10 μm.

FIG. 9illustrates an embodiment of a laser device300configured to connect the non-metallic body10and the first alloy30together. The laser device300includes a laser source320and a second controller310coupled to the laser source320. The second controller310controls the laser source320to emit laser beams50(shown inFIG. 5). In the embodiment, the second controller310controls the laser source320to emit the laser beams50to the non-metallic body10containing the composite layer20and the first alloy30, which melts the first alloy30, at least a portion of the composite layer20, and at least a portion of the non-metallic body10.

The laser device300further includes a cavity (not shown), a beam expander330, and a scanner340. The cavity can receive an object. The beam expander330is connected to the laser source320, and can adjust a diameter and a divergence angle of the laser beams50from the laser source320. The scanner340is connected to the beam expander330, and can apply the laser beams50from the beam expander330onto the object, thereby treating the surface of the object. In the embodiment, the laser source320is a fiber laser source. The object to be processed is the non-metallic body10containing the composite layer20and the first alloy30.

The second controller310stores information as to a set of light emission paths. The second controller310can control the laser beams50to 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.

FIG. 12illustrates an embodiment of a method for manufacturing the connecting article100, the method can begin at block S1.

At block S1, referring toFIG. 1, the non-metallic body10is provided. The non-metallic body10has the surface12. The non-metallic body10includes, but is not limited to, ceramics, glass, plastics, and polymers. The thickness of the non-metallic body10is such that the non-metallic body10is completely melted under a laser treatment. In an embodiment, the thickness of the non-metallic body10is in a range from 40 μm to 200 μm.

At block S2, referring toFIG. 2, the composite layer20is disposed on the surface12of the non-metallic body10through a surface treatment process. The surface treatment process may need to be performed multiple times on the surface12. The surface treatment process may also be performed by dividing the surface12into various regions and separately treating different regions. Referring toFIG. 5, the composite layer20includes the second alloy22and the oxide layer24. The oxide layer24is partially oxidized by the second alloy22. Specifically, the second alloy22is first disposed on the non-metallic body10by a metallization process. The non-metallic body10containing the second alloy22is loaded into the heat treatment furnace430, which oxidizes a portion of the second alloy22to form the oxide layer24. The composite layer20improves the surface wettability of the non-metallic body10, thereby improving the connecting strength of the non-metallic body10and the first alloy30.

At block S3, referring toFIG. 3, the first alloy30is disposed on the composite layer20. The first alloy30is in form of powders laid on the composite layer20. When absorbing laser energy, the first alloy30is melted. The first alloy30and the composite layer20have similar physical and chemical properties, such as thermal expansion coefficient, thermal conductivity, and electrical conductivity. In an embodiment, the second alloy22is iron-based alloy, the first alloy30is stainless steel to match the iron-based alloy.

In an embodiment, the first alloy30has 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 article100, thereby ensuring the quality of the connecting article100.

Furthermore, the particle size of the first alloy30is in a range from 15 μm to 53 μm. The first alloy30with 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 alloy30with a small particle size is more uniformly distributed on the composite layer20, ensuring the quality of the connecting article100. When the first alloy30has a small particle size, gaps between the powders are also small, and a high packing density is obtained. Thus, the connecting article100has a high density, which improves the strength and the surface quality of the connecting article100. However, when the particle size of the first alloy30is too small, the powders of the first alloy30tend to adhere to each other, decreasing the powder flowability of the first alloy30. Thus, uneven powder spreadability is the result, which affects the quality of the connecting article100.

In an embodiment, the first alloy30includes 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 alloy30combines 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 toFIGS. 4 and 5, the laser beams50are emitted toward the first alloy30, which melt the first alloy30, at least a portion of the composite layer20, and at least a portion of the non-metallic body10, thereby connecting the non-metallic body10and the first alloy30together. The process of emitting the laser beams50toward the first alloy30and the melting the first alloy30, at least a portion of the composite layer20, and at least a portion of the non-metallic body10is selective laser melting (SLM).

Referring toFIG. 5, the non-metallic body10, the composite layer20, and the first alloy30are divided into three regions, that is, region I, region II, and region III in that order. Region III shows the non-metallic body10, the composite layer20, and the first alloy30before the laser treatment. When irradiated by the laser beams50, the first alloy30, at least a portion of the composite layer20, and at least a portion of the non-metallic body10are melted to form a tiny molten pool60, as shown in region II. After the laser treatment, the molten material in the molten pool60is solidified to form the bonding layer40. The bonding layer40is connected to a remaining portion of the non-metallic body10which remains unmelted to form the connecting article100, as shown in region I.

Furthermore, by controlling the energy density of the laser beams50through the second controller310, the depth and the width of the molten pool60can be controlled. In an embodiment, the power of the laser source320is in a range from 160 W to 220 W. The scanning speed of the laser beams50is in a range from 800 mm/s to 1200 mm/s. The depth of the molten pool60is 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 body10are 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 body10is silicate glass. The second alloy22is iron-based alloy. The first alloy30is stainless steel. When irradiated by the laser beams50in an inert gas (such as argon) atmosphere, the silicon and oxygen elements in the silicate glass, and the iron element in the composite layer20and the first alloy30, react to form a new phase Fe2SiO4, which is the key factor for tightly connecting the glass and the first alloy30. 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 alloy30are oxidized. The physical and chemical properties of the glass and the first alloy30are quite different, but the composite layer20plays a key role in the connection between the composite layer20and the non-metallic body10. By controlling the thickness and the composition of the composite layer20, the connecting article100with a high quality can be obtained.

In an embodiment, block S3and block S4can be repeated a number of times (for example, 10 times to 20 times). That is, the first alloy30is disposed on the composite layer20, and the SLM process is performed. Then, the first alloy30is again disposed on the composite layer20and another SLM process is performed. Finally, the first alloy30, at least a portion of the composite layer20, and at least a portion of the non-metallic body10are integrally connected.

Furthermore, the laser beams50can 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 beams50through more than one light emission path reduces the residual stress.

Referring toFIGS. 10 and 11, the SLM process is performed through “checkerboard” light emission paths. That is, the surface to be processed (that is, the surface12) is divided into multiple regions spaced from each other, such as multiple square regions of 5 mm*5 mm for example. Different regions are irradiated by the laser beams50one by one. Referring toFIG. 10, the bonding layer40is first formed on the entire surface12. The bonding layer40can be formed by disposing the first alloy30on the entire surface12, and irradiating the first alloy30on each region by the laser beams50through a first light emission path. The angle between the first light emission paths on adjacent regions is 90 degrees. The “checkerboard” light emission paths reduce residual stress in the connecting article100, and prevent the melted material from separating from the unmelted non-metallic body10due to stresses arising during solidification.

Then, referring toFIG. 11, another bonding layer40is formed on the previous bonding layer40. The another bonding layer40can be formed by disposing the first alloy30again on the entire surface12, and irradiating the first alloy30on each region by the laser beams50through a second light emission path. The angle θ between the first light emission path and the second light emission path on the same regions is in a range from 40 degrees to 80 degrees. When the angle θ is less than 40 degrees or greater than 80 degrees, the scanning directions of the laser beams50for forming the bonding layers40on the same region are too close, which generates concentrations of stress. On the other hand, when the angle θ is in the range from 40 degrees to 80 degrees, the stresses are uniformly distributed, and the total residual stress is at a minimum. Thus, the smallest possible deformation of the connecting article100can be obtained. The density of the connecting article100reaches more than 99.9%. The bonding strength can also be increased. In operation, after forming the bonding layer40through the first light emission path, the second light emission path in the same region can be rotated by an angle θ based on the first light emission path. The angle θ can also be selected from 45 degrees, 50 degrees, 37 degrees, 70 degrees, and so on.

The method improves the surface wettability of the non-metallic body10by providing the composite layer20on the non-metallic body10during the bonding process. The connecting strength between the non-metallic body10and the first alloy30can also be increased. The materials of the composite layer20and the first alloy30are not limited, so the bonding layer40can 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.

Comparative Example 1

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.

Comparative Example 2

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.

Comparative Example 3

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 article100has 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 layer20is almost equal to the thickness of the second alloy22plus the thickness of the oxide layer24.