A device and working method for SLM forming copper alloy on ceramic substrate

Abstract

The present application discloses a device for SLM forming copper alloy on a ceramic substrate and its working method. The device includes a forming cavity with a forming cylinder at the bottom; a forming device including a first telescopic rod and a forming base plate, the first telescopic rod driving the forming base plate to rise and fall in the forming cylinder, and the forming base plate is provided with a heating mechanism to heat the ceramic substrate; a powder spreading device for spreading copper powder on the ceramic substrate; a laser optical path and scanning device including an infrared laser, a green laser, and a scanning galvanometer, the lasers emitted by the infrared laser and the green laser are both directed to the scanning galvanometer, and the scanning galvanometer projects the laser onto the ceramic substrate. The present application heats the ceramic substrate through the forming base plate to reduce the temperature gradient difference between the ceramic substrate and the copper alloy powder; at the same time, the infrared laser is used to modify the surface of the ceramic substrate so that the first layer of copper alloy and the ceramic substrate form a ceramic-copper alloy composite layer, thereby ensuring the quality of the formed first layer.

Description

Technical Field

[0001] The present application relates to the field of laser additive manufacturing technology, and in particular to a device for SLM forming copper alloy on a ceramic substrate and a working method thereof. Background Art

[0002] Selective laser melting (SLM) is a major technology in laser additive manufacturing. Using a laser beam as the primary energy source, it scans specific areas of a powder bed based on 3D model slice data, melting and solidifying the metal powder into a part.

[0003] The laser selectively melts the powder and stacks it layer by layer to form it. During conventional forming, the forming cavity is filled with protective gases such as N2 or Ar. The forming cylinder first reduces the thickness of a layer, and then the powder laying vehicle lays a layer of powder on the powder bed. The laser scanning system is then turned on to scan the specified area of ​​the powder bed according to the slicing data, so that the powder absorbs energy, melts, and solidifies into parts. This cycle repeats until the part is formed.

[0004] However, when SLM forming copper alloys, due to their low laser absorptivity, high-power laser scanning rates are often used to increase the energy density absorbed by pure copper. However, this fundamentally fails to overcome the drawback of low laser absorptivity. Furthermore, the high electrical and thermal conductivity of copper and its alloys increases the heat transfer rate from the molten pool to the surrounding area during the forming process, leading to increased local thermal gradients. This in turn leads to common defects such as curling and delamination of part layers, as well as high porosity within the same layer. Furthermore, when forming copper alloy parts using ceramic substrates, the high temperature gradient between the substrate and the material, as well as the differences in substrate and powder material, results in poor adhesion between the substrate and the part, leading to defects such as warping and deformation at the bottom of the copper alloy part. This poor adhesion also directly contributes to the instability and unevenness of the molten pool. The low laser absorptivity and high thermal conductivity of copper alloys, as well as the poor adhesion between the substrate and the part, are detrimental to the practical application of SLM forming of copper alloys. Summary of the Invention

[0005] The purpose of this application is to solve at least one of the technical problems existing in the prior art, and to provide a device and a working method for SLM forming copper alloy on a ceramic substrate, which can increase the bonding strength between the first layer of the copper alloy and the ceramic substrate when forming the copper alloy, thereby reducing the risk of deformation of the copper alloy.

[0006] According to an embodiment of the first aspect of the present application, a device for SLM forming a copper alloy on a ceramic substrate is provided, comprising:

[0007] A molding cavity, wherein a molding cylinder is provided at the bottom of the molding cavity;

[0008] A forming device, the forming device comprising a first telescopic rod and a forming base plate, the forming base plate being mounted on an end of the first telescopic rod, the first telescopic rod driving the forming base plate to rise and fall in the forming cylinder, the forming base plate carrying a ceramic substrate, and the forming base plate being provided with a heating mechanism for heating the ceramic substrate;

[0009] A powder spreading device, the powder spreading device is used to spread copper alloy powder on the ceramic substrate;

[0010] A laser optical path and scanning device, comprising an infrared laser, a green laser, and a scanning galvanometer. The lasers emitted by the infrared laser and the green laser are directed toward the scanning galvanometer, which projects the lasers onto the ceramic substrate.

[0011] The laser light emitted by the infrared laser can modify the surface of the ceramic substrate, and the laser light emitted by the green laser can fuse the first layer of copper alloy with the modified surface of the ceramic substrate to form a ceramic-copper alloy composite layer.

[0012] According to the embodiment of the first aspect of the present application, further, the device for SLM forming copper alloy on a ceramic substrate also includes a temperature sensor, which is installed in the forming cavity and is used to detect the melting temperature of the copper alloy powder.

[0013] According to the embodiment of the first aspect of the present application, further, the device for SLM forming copper alloy on the ceramic substrate also includes a powder feeding device, and a powder cylinder is also provided at the bottom of the forming cavity. The powder feeding device includes a second telescopic rod and a powder cylinder bottom plate, and the powder cylinder bottom plate is installed at the end of the second telescopic rod. The second telescopic rod drives the powder cylinder bottom plate to rise and fall in the powder cylinder, and the powder cylinder bottom plate carries copper alloy powder; after the powder cylinder bottom plate pushes the copper alloy powder out of the powder cylinder, the powder spreading device spreads the copper alloy powder on the ceramic substrate.

[0014] According to the first aspect embodiment of the present application, further, the powder spreading device includes a slide rail and a powder spreading scraper, the slide rail is fixedly installed inside the molding cavity, the powder spreading scraper is slidably connected to the slide rail, and the powder spreading scraper scrapes the copper alloy powder onto the ceramic substrate.

[0015] According to the first embodiment of the present application, further, a powder dropping trough is provided at the bottom of the molding cavity, and the powder scraper can scrape excess copper alloy powder into the powder dropping trough for recovery.

[0016] According to the embodiment of the first aspect of the present application, further, the molding cavity is filled with protective gas.

[0017] According to the first aspect embodiment of the present application, further, the device for SLM forming copper alloy on a ceramic substrate also includes a protective gas circulation system, and an air inlet and an air outlet connected to the protective gas circulation system are opened in the forming cavity, and the protective gas circulation system is used to supply protective gas to the forming cavity.

[0018] According to the embodiment of the first aspect of the present application, further, the laser optical path and scanning device also includes a first reflector and a second reflector, the laser emitted by the infrared laser is reflected to the scanning galvanometer via the first reflector, and the laser emitted by the green laser is reflected to the scanning galvanometer via the second reflector.

[0019] According to a second embodiment of the present application, a method for operating the apparatus for SLM forming a copper alloy on the ceramic substrate is provided, comprising:

[0020] The first telescopic rod lifts the forming base plate to the highest position, and fixes the ceramic substrate on the forming base plate;

[0021] Turning on the heating mechanism inside the forming base plate to heat the ceramic substrate;

[0022] When the temperature of the ceramic substrate reaches a threshold, the infrared laser is turned on, and the infrared laser is irradiated onto the ceramic substrate via the scanning galvanometer, thereby modifying the surface of the ceramic substrate;

[0023] The powder spreading device spreads the copper alloy powder on the surface of the ceramic substrate;

[0024] The infrared laser is turned off, and the green laser is turned on. The green laser is irradiated onto the ceramic substrate via the scanning galvanometer, so that the copper alloy powder on the ceramic substrate is melted and re-solidified into the current layer.

[0025] The first telescopic rod drives the forming base plate to descend, the powder spreading device spreads the copper alloy powder on the current layer, and the green laser continues to melt and solidify the next layer of pattern;

[0026] The laser forming of each slice is repeated in a cycle until a whole part is obtained.

[0027] According to an embodiment of the second aspect of the present application, further, the heating temperature threshold of the ceramic substrate is 400 to 500°C.

[0028] The beneficial effects of the embodiments of the present application include at least: the present application heats the ceramic substrate through the forming base plate, thereby reducing the temperature gradient difference between the ceramic substrate and the copper alloy powder; at the same time, an infrared laser is used to modify the surface of the ceramic substrate, so that the first layer of copper alloy and the ceramic substrate form a ceramic-copper alloy composite layer, thereby ensuring the quality of the formed first layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described are only part of the embodiments of this application, not all of them. Those skilled in the art can also derive other design solutions and drawings based on these drawings without inventive effort.

[0030] Figure 1 2 is a schematic structural diagram of an apparatus for SLM forming a copper alloy on a ceramic substrate according to the first aspect of the present application;

[0031] Figure 2 Schematic diagram of using infrared laser to modify the surface of a ceramic substrate 700 in the working method of the embodiment of the second aspect of the present application;

[0032] Figure 3 This is a schematic diagram of forming a first layer of copper alloy using a green laser in the working method of the embodiment of the second aspect of the present application;

[0033] Figure 4 This is a schematic diagram of using green light laser to form copper alloy in the working method of the second embodiment of the present application.

[0034] Figure markings: 100-molding cavity, 110-molding cylinder, 120-powder cylinder, 130-powder drop trough, 200-molding device, 210-first telescopic rod, 220-molding base plate, 300-powder spreading device, 310-slide rail, 320-powder spreading scraper, 400-laser optical path and scanning device, 410-infrared laser, 420-green laser, 430-scanning galvanometer, 440-first reflector, 450-second reflector, 500-temperature sensor, 600-powder supply device, 610-second telescopic rod, 620-powder cylinder base plate, 700-ceramic substrate. DETAILED DESCRIPTION

[0035] This section will describe the specific embodiments of the present application in detail. The preferred embodiments of the present application are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present application, but it cannot be understood as a limitation on the scope of protection of the present application.

[0036] In the description of this application, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0037] In the description of this application, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The terms "first" and "second" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly specifying the number or order of the technical features indicated.

[0038] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0039] When forming copper alloys using SLM, high-power laser scanning rates are often used to increase the energy density absorbed by pure copper due to its low laser absorptivity. However, this fundamentally fails to overcome the drawbacks of low laser absorptivity. Furthermore, the high electrical and thermal conductivity of copper and its alloys increases the heat transfer rate from the molten pool to the surrounding area during the forming process, leading to increased local thermal gradients. This in turn leads to common defects such as part layer curling and delamination, as well as high porosity within the same layer. Furthermore, when forming copper alloy parts using ceramic substrates, the high temperature gradient between the substrate and the material, as well as the material differences between the substrate and the powder, leads to poor adhesion between the substrate and the part, resulting in warping and deformation at the bottom of the copper alloy part. This poor adhesion also directly contributes to an unstable and uneven molten pool. The low laser absorptivity and high thermal conductivity of copper alloys, as well as the poor adhesion between the substrate and the part, hinder the practical application of SLM forming of copper alloys.

[0040] In this regard, the present application proposes a device for SLM forming copper alloy on a ceramic substrate and a working method thereof, wherein the ceramic substrate 700 is heated by a forming base plate 220 to reduce the temperature gradient difference between the ceramic substrate 700 and the copper alloy powder; at the same time, an infrared laser is used to modify the surface of the ceramic substrate 700 so that the first layer of copper alloy and the ceramic substrate 700 form a ceramic-copper alloy composite layer, thereby ensuring the quality of the formed first layer.

[0041] Reference Figure 1The device for SLM forming copper alloy on a ceramic substrate in the embodiment of the first aspect of the present application includes a forming cavity 100, a forming device 200, a powder spreading device 300 and a laser optical path and scanning device 400. Among them, the forming cavity 100 is the main structure of the device for SLM forming copper alloy on a ceramic substrate. It is a closed box, and the laser additive process is carried out inside the forming cavity 100. The forming device 200 is used to drive the ceramic substrate 700 to move up and down to complete the layer-by-layer slicing and manufacturing of copper alloy parts. The powder spreading device 300 is used to spread copper alloy powder on the ceramic substrate 700. The laser optical path and scanning device 400 is used to modify the surface of the ceramic substrate 700 and complete the subsequent melting of the copper alloy powder. After the copper alloy powder is melted and then solidified, the slices of this layer of parts can be obtained.

[0042] Specifically, a forming cylinder 110 is provided at the bottom of the forming cavity 100, and the forming device 200 includes a first telescopic rod 210 and a forming base plate 220. The forming base plate 220 is installed at the end of the first telescopic rod 210, and the first telescopic rod 210 drives the forming base plate 220 to rise and fall in the forming cylinder 110. The forming base plate 220 carries a ceramic substrate 700, so that the forming base plate 220 drives the ceramic substrate 700 to rise and fall. It is worth noting that the forming base plate 220 is provided with a heating mechanism to heat the ceramic substrate 700, and the heating mechanism can be an electric heating wire. By heating the ceramic substrate 700, the adhesion between the first layer of copper alloy and the ceramic substrate 700 is maintained, and the high temperature facilitates the surface modification of the ceramic substrate 700.

[0043] The laser optical path and scanning device 400 includes an infrared laser 410, a green laser 420, and a scanning galvanometer 430. The lasers emitted by the infrared laser 410 and the green laser 420 are both directed toward the scanning galvanometer 430, which then projects the lasers onto the ceramic substrate 700. The infrared laser 410 and the green laser 420 can each emit lasers of different wavelengths. The laser light emitted by the infrared laser 410 can modify the surface of the ceramic substrate 700, while the laser light emitted by the green laser 420 can fuse the first layer of copper alloy with the modified surface of the ceramic substrate 700 to form a ceramic-copper alloy composite layer, thereby improving the molding quality of the first layer of copper alloy and enhancing its bonding strength with the ceramic substrate 700.

[0044] Furthermore, the apparatus for SLM forming a copper alloy on a ceramic substrate includes a temperature sensor 500, which is installed within the forming cavity 100 and is used to detect the melting temperature of the copper alloy powder, thereby better regulating the output power of the infrared laser 410 and the green laser 420. The temperature sensor 500 is specifically an infrared temperature sensor that measures the temperature of the copper alloy powder in a non-contact manner.

[0045] Furthermore, the device for SLM forming copper alloy on ceramic substrates also includes a powder supply device 600. A powder cylinder 120 is provided at the bottom of the forming cavity 100, and the powder supply device 600 includes a second telescopic rod 610 and a powder cylinder bottom plate 620. The powder cylinder bottom plate 620 is mounted on the end of the second telescopic rod 610, and the second telescopic rod 610 drives the powder cylinder bottom plate 620 to rise and fall in the powder cylinder 120, and the powder cylinder bottom plate 620 carries copper alloy powder. When the second telescopic rod 610 is extended, the copper alloy powder can be pushed out of the powder cylinder 120 through the powder cylinder bottom plate 620, and the powder spreading device 300 spreads the copper alloy powder on the ceramic substrate 700.

[0046] Furthermore, the powder spreading device 300 includes a slide rail 310 and a powder spreading scraper 320. The slide rail 310 is fixedly installed inside the molding cavity 100, and the powder spreading scraper 320 is slidably connected to the slide rail 310. As the powder spreading scraper 320 slides along the slide rail 310, the powder spreading scraper 320 scrapes the copper alloy powder onto the ceramic substrate 700, completing the loading of the copper alloy powder.

[0047] Furthermore, a powder dropping trough 130 is provided at the bottom of the molding cavity 100 , and the powder scraper 320 can scrape excess copper alloy powder into the powder dropping trough 130 for recycling.

[0048] Furthermore, the forming cavity 100 is filled with a protective gas, such as nitrogen or argon. The apparatus for SLM forming a copper alloy on a ceramic substrate also includes a protective gas circulation system. The forming cavity 100 is provided with an air inlet and an air outlet connected to the protective gas circulation system, which is used to supply the protective gas to the forming cavity 100.

[0049] Furthermore, the laser optical path and scanning device 400 also includes a first reflector 440 and a second reflector 450. The laser light emitted by the infrared laser 410 is reflected by the first reflector 440 to the scanning galvanometer 430, and the laser light emitted by the green laser 420 is reflected by the second reflector 450 to the scanning galvanometer 430. By providing the first reflector 440 and the second reflector 450, the installation positions of the infrared laser 410 and the green laser 420 are more flexible, and the angles at which the infrared laser and the green laser enter the scanning galvanometer 430 can be adjusted by adjusting the angles of the first reflector 440 and the second reflector 450.

[0050] In an embodiment of the second aspect of the present application, a working method of the apparatus for SLM forming a copper alloy on a ceramic substrate includes the following steps:

[0051] S100. The first telescopic rod 210 raises the forming base plate 220 to its highest position, and the ceramic substrate 700 is fixed to the forming base plate 220;

[0052] S200 turns on the heating mechanism inside the forming base plate 220 to heat the ceramic substrate 700, the heating temperature threshold is 400 to 500 ℃;

[0053] S300. After the temperature of the ceramic substrate 700 reaches the threshold, refer to Figure 2 , turning on the infrared laser 410, the infrared laser is irradiated onto the ceramic substrate 700 through the scanning galvanometer 430, so as to modify the surface of the ceramic substrate 700;

[0054] S400 powder laying group, 300 copper alloy powder is laid on the surface of the ceramic substrate 700;

[0055] S500. Reference Figure 3 , turn off the infrared laser 410, turn on the green laser 420, and the green laser is irradiated to the ceramic substrate 700 through the scanning galvanometer 430, so that the copper alloy powder on the ceramic substrate 700 melts and re-solidifies into the current layer;

[0056] S600. The first telescopic rod 210 drives the forming base plate 220 downward, and the powder spreading device 300 spreads the copper alloy powder on the current layer. The green laser continues to melt and solidify the next layer of the pattern.

[0057] S700. Reference Figure 4 , laser forming of each layer of slices is repeated until a whole part is obtained.

[0058] The above is a specific description of the preferred implementation methods of the present application, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A device for SLM forming copper alloy on a ceramic substrate, characterized in that: include: A molding cavity, wherein a molding cylinder is provided at the bottom of the molding cavity; A forming device, the forming device comprising a first telescopic rod and a forming base plate, the forming base plate being mounted on an end of the first telescopic rod, the first telescopic rod driving the forming base plate to rise and fall in the forming cylinder, the forming base plate carrying a ceramic substrate, and the forming base plate being provided with a heating mechanism for heating the ceramic substrate; A powder spreading device, the powder spreading device is used to spread copper alloy powder on the ceramic substrate; A laser optical path and scanning device, comprising an infrared laser, a green laser, and a scanning galvanometer. The lasers emitted by the infrared laser and the green laser are directed toward the scanning galvanometer, which projects the lasers onto the ceramic substrate. The laser light emitted by the infrared laser modifies the surface of the ceramic substrate by scanning and heating, and the laser light emitted by the green laser can fuse the first layer of copper alloy with the modified surface of the ceramic substrate to form a ceramic-copper alloy composite layer.

2. The apparatus for SLM forming copper alloy on a ceramic substrate according to claim 1, characterized in that: The apparatus for SLM forming copper alloy on a ceramic substrate further includes a temperature sensor, which is installed in the forming cavity and is used to detect the temperature of the powder bed or the forming base plate.

3. The apparatus for SLM forming copper alloy on a ceramic substrate according to claim 1, characterized in that: The device for SLM forming copper alloy on a ceramic substrate also includes a powder feeding device. A powder cylinder is also provided at the bottom of the forming cavity. The powder feeding device includes a second telescopic rod and a powder cylinder bottom plate. The powder cylinder bottom plate is installed at the end of the second telescopic rod. The second telescopic rod drives the powder cylinder bottom plate to rise and fall in the powder cylinder. The powder cylinder bottom plate carries copper alloy powder. After the powder cylinder bottom plate pushes the copper alloy powder out of the powder cylinder, the powder spreading device spreads the copper alloy powder on the ceramic substrate.

4. The apparatus for SLM forming copper alloy on a ceramic substrate according to claim 1, characterized in that: The powder spreading device includes a slide rail and a powder spreading scraper. The slide rail is fixedly installed inside the molding cavity. The powder spreading scraper is slidably connected to the slide rail. The powder spreading scraper scrapes the copper alloy powder onto the ceramic substrate.

5. The apparatus for SLM forming copper alloy on a ceramic substrate according to claim 4, characterized in that: A powder dropping trough is further provided at the bottom of the molding cavity, and the powder scraper can scrape excess copper alloy powder into the powder dropping trough for recycling.

6. The apparatus for SLM forming copper alloy on a ceramic substrate according to claim 1, characterized in that: The molding cavity is filled with protective gas.

7. The apparatus for SLM forming copper alloy on a ceramic substrate according to claim 6, characterized in that: The device for SLM forming copper alloy on ceramic substrate also includes a protective gas circulation system. An air inlet and an air outlet connected to the protective gas circulation system are opened in the forming cavity. The protective gas circulation system is used to supply protective gas to the forming cavity.

8. The apparatus for SLM forming copper alloy on a ceramic substrate according to claim 1, characterized in that: The laser light path and scanning device further includes a first reflector and a second reflector. The laser light emitted by the infrared laser is reflected to the scanning galvanometer by the first reflector, and the laser light emitted by the green laser is reflected to the scanning galvanometer by the second reflector.

9. A method for operating the device for SLM forming copper alloy on a ceramic substrate according to any one of claims 1 to 8, characterized in that: include: The first telescopic rod lifts the forming base plate to the highest position, and fixes the ceramic substrate on the forming base plate; Turning on the heating mechanism inside the forming base plate to heat the ceramic substrate; After the temperature of the ceramic substrate reaches a threshold, the infrared laser is turned on, and the infrared laser is irradiated onto the ceramic substrate through the scanning galvanometer to modify the surface of the ceramic substrate, wherein the heating temperature threshold of the ceramic substrate is 400 to 500° C.; The powder spreading device spreads the copper alloy powder on the surface of the ceramic substrate; The infrared laser is turned off, and the green laser is turned on. The green laser is irradiated onto the ceramic substrate via the scanning galvanometer, so that the copper alloy powder on the ceramic substrate is melted and re-solidified into the current layer. The first telescopic rod drives the forming base plate to descend, the powder spreading device spreads the copper alloy powder on the current layer, and the green laser continues to melt and solidify the next layer of pattern; The laser forming of each slice is repeated in a cycle until a whole part is obtained.

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