Silicon carbide connection method

Abstract

The embodiments of the present application provide a method for connecting silicon carbide. The connection method includes: using a pulsed laser deposition method to deposit a dense aluminum-titanium nanoparticle layer on the surface of a silicon carbide substrate; docking the silicon carbide substrates deposited with the aluminum-titanium nanoparticle layer; and brazing the docked silicon carbide substrates to connect the silicon carbide substrates into one. In the method for connecting silicon carbide provided by the embodiments of the present application, the aluminum-titanium nanoparticle layer can be used as a connecting layer for connecting the silicon carbide substrates; at the same time, the particles of the connecting layer deposited by the pulsed laser deposition method are nanometer-sized, which can reduce the temperature required for brazing the silicon carbide substrate; in addition, using the pulsed laser deposition method, the connecting layer can be deposited on the surface of silicon carbide substrates of more shapes, reducing the restrictions on the connection caused by the shape of the silicon carbide substrate.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of material connection, and specifically to a method for connecting silicon carbide. Background Art

[0002] Silicon carbide (SiC) boasts excellent high-temperature properties, good radiation resistance, a low neutron absorption cross-section, low activation, and low tritium permeability, making it well-suited for use in nuclear reactors. However, SiC suffers from poor machinability and difficulty achieving a net shape. Therefore, SiC must be joined with other SiC or other materials to produce larger and more complex devices.

[0003] Related technologies include methods for joining silicon carbide, such as applying a slurry of Al and Si powders to a silicon carbide substrate as a connecting layer, which is then used to connect the silicon carbide substrate; or using a high-entropy metal infiltrating phase in the form of a vapor phase to infiltrate the silicon carbide substrate as a connecting layer, which is then used to connect the silicon carbide substrate. However, these methods make it difficult to control the thickness of the connecting layer, and the welding temperature is relatively high, resulting in poor silicon carbide connection results. Summary of the Invention

[0004] In view of the above problems, an embodiment of the present application provides a method for connecting silicon carbide, comprising: using a pulsed laser deposition method to deposit a dense aluminum-titanium nanoparticle layer on the surface of a silicon carbide substrate; docking the silicon carbide substrates deposited with the aluminum-titanium nanoparticle layer; and brazing the docked silicon carbide substrates to connect the silicon carbide substrates into one.

[0005] In the silicon carbide connection method provided in the embodiments of the present application, the aluminum-titanium nanoparticle layer can be used as a connection layer for connecting the silicon carbide substrate. By adjusting the working parameters during pulsed laser deposition, the composition and thickness of the connection layer can be controlled, so that the thickness and composition of the connection layer are uniform and controllable; at the same time, the particles of the connection layer deposited by the pulsed laser deposition method are nanometer-sized, which can reduce the temperature required for brazing the silicon carbide substrate, making the connection process of the silicon carbide substrate easier; in addition, using the pulsed laser deposition method, the connection layer can be deposited on the surface of silicon carbide substrates of more shapes, reducing the restrictions on the connection caused by the shape of the silicon carbide substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0007] Figure 1 Schematic diagram of the process of connecting silicon carbide according to an embodiment of the present application;

[0008] Figure 2Schematic diagram of depositing a dense aluminum-titanium nanoparticle layer on the surface of a silicon carbide substrate using a pulsed laser deposition system according to an embodiment of the present application;

[0009] Figure 3 This is a schematic diagram of docking a silicon carbide substrate deposited with an aluminum-titanium nanoparticle layer according to an embodiment of the present application;

[0010] Figure 4 This is a schematic diagram of a process for docking a silicon carbide substrate deposited with an aluminum-titanium nanoparticle layer according to an embodiment of the present application;

[0011] Figure 5 This is a schematic diagram of depositing a dense aluminum-titanium nanoparticle layer on a silicon carbide substrate surface using a pulsed laser deposition system according to another embodiment of the present application;

[0012] Figure 6 A schematic diagram of docking a silicon carbide substrate deposited with an aluminum-titanium nanoparticle layer according to another embodiment of the present application;

[0013] Figure 7 A schematic diagram of a process for docking a silicon carbide substrate deposited with an aluminum-titanium nanoparticle layer according to another embodiment of the present application;

[0014] Figure 8 This is a morphology diagram of the aluminum-titanium nanoparticle layer according to an embodiment of the present application;

[0015] Figure 9 This is a morphology diagram of the aluminum-titanium nanoparticle layer after heating according to an embodiment of the present application.

[0016] It should be noted that the drawings are not necessarily drawn to scale, and are merely shown in a schematic manner that does not affect the understanding of those skilled in the art. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. For the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0018] The present invention provides a method for connecting silicon carbide substrates. The method can connect multiple silicon carbide substrates. In this embodiment, a connection layer is deposited on the surface of the silicon carbide substrate, and then the multiple silicon carbide substrates are connected by brazing.

[0019] Figure 1Schematic diagram of the process of connecting silicon carbide according to the embodiment of the present application. Figure 1 As shown, the method for connecting silicon carbide may include steps S101 to S103.

[0020] Specifically, in step S101, a dense aluminum-titanium nanoparticle layer is deposited on the surface of a silicon carbide substrate using a pulsed laser deposition method; in step S102, the silicon carbide substrates on which the aluminum-titanium nanoparticle layer is deposited are butted; and in step S102, the butted silicon carbide substrates are brazed to connect the silicon carbide substrates into one.

[0021] In the silicon carbide connection method provided in the embodiments of the present application, the aluminum-titanium nanoparticle layer can be used as a connecting layer for connecting the silicon carbide substrate. By adjusting the working parameters during pulsed laser deposition, the composition and thickness of the connecting layer can be controlled, so that the thickness and composition of the connecting layer are uniform and controllable.

[0022] At the same time, the particles of the connecting layer deposited by the pulsed laser deposition method are nanometer-sized. Using the connecting layer formed by nanometer-sized aluminum-titanium nanoparticles as solder can reduce the temperature required for brazing the silicon carbide substrate, making the connection process of the silicon carbide substrate easier.

[0023] In addition, the pulsed laser deposition method forms a connecting layer by sputtering nanoparticles from the target material, which are then deposited on the surface of the silicon carbide substrate. Therefore, using the pulsed laser deposition method, a connecting layer can be deposited on the surface of silicon carbide substrates of more shapes, reducing the restrictions of the shape of the silicon carbide substrate on the connection.

[0024] In some embodiments, the step of depositing an aluminum-titanium nanoparticle layer on the surface of a silicon carbide substrate using a pulsed laser deposition method may include: heating the silicon carbide substrate; under vacuum conditions, bombarding an aluminum target and a titanium target with a dual-beam pulsed laser, respectively, so that aluminum nanoparticles and titanium nanoparticles sputtered from the aluminum target and the titanium target are simultaneously deposited on the surface of the silicon carbide substrate.

[0025] In some embodiments, a pulsed deposition system may be used to perform deposition processing on the surface of the silicon carbide substrate. Figure 2 This is a schematic diagram of depositing a dense aluminum-titanium nanoparticle layer on the surface of a flat silicon carbide substrate using a pulsed laser deposition system according to an embodiment of the present application. Figure 5 Schematic diagram of depositing a dense aluminum-titanium nanoparticle layer on the surface of a silicon carbide substrate in the shape of an end plug using a pulsed laser deposition system according to an embodiment of the present application.

[0026] like Figure 2 and Figure 5As shown, the pulsed laser deposition system may include a sample stage 10, a first target stage 21, a second target stage 22, a first pulsed laser 31, a second pulsed laser 32, and a vacuum chamber 40. The sample stage 10, the first target stage 21, the second target stage 22, the first pulsed laser 31, and the second pulsed laser 32 may be disposed in the vacuum chamber 40.

[0027] The sample stage 10 is used to support a silicon carbide substrate 100. The sample stage 10 is configured to rotate, thereby driving the silicon carbide substrate 100 mounted thereon to rotate together. The sample stage 10 is also configured to heat the silicon carbide substrate 100, which facilitates the deposition of nanoparticles. In some embodiments, the heating temperature of the sample stage 10 can range from 0 to 600°C, preferably to 500°C.

[0028] The first target stage 21 and the second target stage 22 are used to support the first target 200 and the second target 300, respectively. In this embodiment, the first target 200 can be an aluminum target, and the second target 300 can be a titanium target. The metal purity of the aluminum and titanium targets can be 99.999%. The first and second target stages 21 and 22 are configured to rotate, respectively driving the first and second targets 200 and 300 mounted thereon to rotate together.

[0029] The first pulsed laser 31 and the second pulsed laser 32 are used to irradiate and bombard the first target material and the second target material disposed on the first target material stage 21 and the second target material stage 22, respectively, so as to sputter out nanoparticles from the target materials. The first pulsed laser 31 and the second pulsed laser 32 are configured with adjustable power to adjust the speed at which the first target material 200 and the second target material 300 sputter out nanoparticles, respectively. The frequency range of the first pulsed laser 31 and the second pulsed laser 32 can be 500kHz to 2MHz, and the pulse width of the pulsed laser generated by the first pulsed laser 31 and the second pulsed laser 32 can be 10ns to 300fs.

[0030] The vacuum chamber 40 is used to provide a vacuum environment for the pulsed laser deposition system to prevent air from interfering with the formation and deposition of nanoparticles. In some embodiments, the vacuum degree provided by the vacuum chamber 40 can range from 500 Pa to 6×10 -3 Pa, in other embodiments, the vacuum chamber 40 can provide 2×10 -4 Vacuum degree in Pa.

[0031] In this embodiment, the silicon carbide substrate 100 can be placed in a vacuum chamber 40 and fixed on a sample stage 10, and the sample stage 10 can be used to heat the silicon carbide substrate 100. At the same time, in the vacuum chamber 40, a dual-beam pulsed laser generated by a first pulsed laser 31 and a second pulsed laser 32 can be used to bombard an aluminum target and a titanium target, respectively. After being bombarded by the laser, the aluminum target and the titanium target will sputter out aluminum nanoparticles and titanium nanoparticles, respectively. The aluminum nanoparticles and titanium nanoparticles move to the surface of the silicon carbide substrate 100 in the vacuum chamber 40 and are deposited on the surface of the silicon carbide substrate 100. The aluminum nanoparticles and titanium nanoparticles sputtered from the aluminum target and the titanium target can be simultaneously deposited on the surface of the silicon carbide substrate 100, making the composition of the aluminum-titanium nanoparticle layer more uniform.

[0032] In some embodiments, the power of the laser bombarding the aluminum target and / or the power of the laser bombarding the titanium target may be adjusted to control the composition of the aluminum-titanium nanoparticle layer.

[0033] It can be understood that the laser power bombarding the aluminum target and the laser power bombarding the titanium target will affect the speed of sputtering aluminum nanoparticles and titanium nanoparticles respectively. Specifically, the higher the laser power, the faster the speed of sputtering of aluminum nanoparticles and titanium nanoparticles, and the more nanoparticles deposited on the surface of the silicon carbide substrate 100 per unit time. Therefore, in this embodiment, by adjusting the laser power bombarding the aluminum target and / or adjusting the laser power bombarding the titanium target, the composition of the aluminum-titanium nanoparticle layer can be controlled. For example, increasing the laser power bombarding the aluminum target and / or reducing the laser power bombarding the titanium target can increase the percentage of aluminum atoms in the aluminum-titanium nanoparticle layer (reflecting the proportion of aluminum nanoparticles).

[0034] In some embodiments, the laser power for bombarding the aluminum target can be 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, or any value between 50 W and 100 W. Correspondingly, the laser power for bombarding the titanium target can be 50 W, 40 W, 30 W, 20 W, 10 W, or any value between 10 W and 50 W. In the aluminum-titanium nanoparticle layer formed at the above powers, the atomic percentage of aluminum can be 50 at %, 60 at %, 70 at %, 80 at %, 90 at %, 100 at %, or any value between 50 at % and 100 at %, respectively. Correspondingly, the atomic percentage of titanium can be 50 at %, 40 at %, 30 at %, 20 at %, 0 at %, or any value between 10 at % and 50 at %.

[0035] In some embodiments, the deposition time of the pulsed laser deposition can be adjusted to control the thickness of the aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate 100 .

[0036] It can be understood that the thickness of the aluminum-titanium nanoparticle layer is affected by the deposition time of the pulsed laser deposition system. Specifically, the longer the deposition time of the pulsed laser deposition system, the more aluminum nanoparticles and titanium nanoparticles are deposited on the surface of the silicon carbide substrate 100, and the thicker the aluminum-titanium nanoparticle layer. Therefore, in this embodiment, by adjusting the deposition time of the pulsed laser deposition system, the thickness of the aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate 100 can be controlled. In some embodiments, by controlling the deposition time, the thickness of the aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate 100 can be adjusted in the range of 10 to 30 μm.

[0037] In some embodiments, during the deposition process, the silicon carbide substrate 100 can be controlled to rotate so as to uniformly deposit the aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate 100. In this embodiment, by controlling the rotation of the silicon carbide substrate 100, different portions of the surface of the silicon carbide substrate 100 can be continuously positioned, avoiding being fixed in the same position in the vacuum chamber 40, thereby achieving more uniform deposition of the aluminum-titanium nanoparticle layer.

[0038] In some embodiments, during the deposition process, the rotation of the aluminum target and the titanium target can be controlled so that the laser evenly bombards the aluminum target and the titanium target. It is understandable that during the deposition process, the aluminum target and the titanium target sputter out aluminum nanoparticles and titanium nanoparticles, respectively, and the aluminum target and the titanium target are continuously consumed, so that the surfaces of the aluminum target and the titanium target may be uneven, causing the sputtering speed of the nanoparticles to change, interfering with the thickness control of the aluminum-titanium nanoparticle layer. Therefore, in this embodiment, by controlling the rotation of the aluminum target and the titanium target, the laser can be evenly bombarded on the aluminum target and the titanium target, making the sputtering speed of the nanoparticles uniform and controllable, which is beneficial to the thickness control of the aluminum-titanium nanoparticle layer.

[0039] In some embodiments, the step of brazing the butted silicon carbide substrates includes: placing the butted silicon carbide substrates in a brazing furnace under vacuum conditions; controlling the brazing furnace to heat up to a predetermined temperature and keeping it warm so that the aluminum phase in the aluminum-titanium nanoparticle layer reacts with the silicon carbide substrate 100 to form a nanoparticle connection layer containing a Ti3Si(Al)C2 phase; and cooling the brazing furnace to obtain a silicon carbide substrate 100 connected as one.

[0040] In this embodiment, the brazing furnace can form a vacuum condition to prevent air from interfering with the brazing process. For example, the brazing furnace can form a vacuum condition of 2×10 -5 Vacuum degree in Pa.

[0041] Because the particle diameters in the aluminum-titanium nanoparticle layer are nanometer-scale, the temperature required for melting the aluminum-titanium nanoparticle layer can be reduced. At a predetermined temperature, the aluminum-titanium nanoparticle layer can melt and react with the silicon carbide substrate 100 to form a Ti3Si(Al)C2 phase, thereby increasing the bonding strength of the silicon carbide substrate 100. In this embodiment, because the thickness of the aluminum-titanium nanoparticle layer is controllable, when the thickness of the aluminum-titanium nanoparticle layer is relatively thin, nearly all of the aluminum phase in the aluminum-titanium nanoparticle layer can react with the silicon carbide substrate 100 to form a Ti3Si(Al)C2 phase, thereby increasing the bonding strength of the silicon carbide substrate 100.

[0042] In some embodiments, the step of controlling the brazing furnace to heat up to a predetermined temperature and maintaining the temperature includes: controlling the brazing furnace to heat up to a first predetermined temperature; maintaining the brazing furnace at the first predetermined temperature for a first predetermined time, and then controlling the brazing furnace to heat up to a second predetermined temperature and maintain the temperature for a second predetermined time. The first predetermined temperature may be a temperature that melts the aluminum phase, for example, 1000°C; the second predetermined temperature may be a temperature that allows the aluminum to completely react with the silicon carbide substrate 100, for example, 1400°C. The heating rate to the first predetermined temperature may be 8°C / min, and the heating rate to the second predetermined temperature may be 6°C / min.

[0043] like Figure 3 and Figure 6 As shown, an upper pressing plate 51 and a lower supporting plate 52 may be provided in the brazing furnace. When brazing two silicon carbide substrates, the aluminum-titanium nanoparticle layers 400 deposited on the two silicon carbide substrates may be firstly butted together by the upper pressing plate 51 and the lower supporting plate 52 .

[0044] Specifically, if Figure 3 and Figure 4 As shown, when brazing two flat silicon carbide substrates 100, one silicon carbide substrate 100 can be fixed on the upper pressing plate 51 with the surface deposited with the aluminum-titanium nanoparticle layer 400 facing downward. At the same time, the other silicon carbide substrate 100 can be fixed on the lower supporting plate 52 with the surface deposited with the aluminum-titanium nanoparticle layer 400 facing upward. The distance between the upper pressing plate 51 and the lower supporting plate 52 is then reduced so that the aluminum-titanium nanoparticle layers 400 deposited on the two silicon carbide substrates contact each other, completing the butt joint. The aluminum-titanium nanoparticle layer 400 is then melted by heating, and the aluminum phase therein reacts with the silicon carbide substrate to form a nanoparticle connecting layer 500 containing the Ti3Si(Al)C2 phase.

[0045] In this embodiment, two flat silicon carbide substrates 100 can be tightly connected to obtain a joint with good airtightness and high-temperature strength. The shear strength of the joint is 102 MPa.

[0046] In another embodiment, Figure 6 and Figure 7 As shown, when brazing the silicon carbide end plug 110 and the silicon carbide cladding 120, an aluminum-titanium nanoparticle layer 400 can be deposited on the surface of the silicon carbide end plug 110. The silicon carbide cladding 120 is then fixed to the lower support plate 52 and inserted into the silicon carbide cladding 120 to complete the connection. The aluminum-titanium nanoparticle layer 400 is then melted by heating, and the aluminum phase therein reacts with the silicon carbide matrix to form a nanoparticle connection layer 500 containing a Ti3Si(Al)C2 phase.

[0047] In this embodiment, the silicon carbide end plug 110 and the silicon carbide cladding 120 can be tightly connected to obtain a joint with good airtightness and high temperature strength. The shear strength of the joint is 94 MPa.

[0048] Figure 8 This is a morphology diagram of the aluminum-titanium nanoparticle layer according to an embodiment of the present application; Figure 9 This is a morphology diagram of the aluminum-titanium nanoparticle layer after heating according to an embodiment of the present application. Figure 8 It shows that the vacuum degree is 8×10 -3 Morphology of the Al-Ti nanoparticle layer with an Al atomic fraction of 20 at% deposited under Pa conditions; Figure 9 It shows that the vacuum degree is 8×10 -3 Pa, aluminum titanium nanoparticle layer morphology with an aluminum atomic fraction of 20 at% deposited under heating conditions of 500 ° C. Figure 8 and Figure 9 As shown, using the method provided in the embodiment of the present application, an aluminum-titanium nanoparticle layer with relatively uniform thickness can be formed.

[0049] The above are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for connecting silicon carbide, characterized in that: include: Using pulsed laser deposition, a dense layer of aluminum and titanium nanoparticles is deposited on the surface of the silicon carbide substrate; docking the silicon carbide substrate on which the aluminum-titanium nanoparticle layer is deposited; Brazing the butted silicon carbide substrates to connect the silicon carbide substrates into one body; The step of depositing a dense aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate by using a pulsed laser deposition method comprises: heating the silicon carbide substrate; Under vacuum conditions, a double-beam pulsed laser is bombarded onto an aluminum target and a titanium target respectively, so that aluminum nanoparticles and titanium nanoparticles sputtered from the aluminum target and the titanium target are simultaneously deposited on the surface of the silicon carbide substrate.

2. The method according to claim 1, characterized in that Also includes: The power of the laser that bombards the aluminum target is adjusted, and / or the power of the laser that bombards the titanium target is adjusted to control the composition of the aluminum-titanium nanoparticle layer.

3. The method according to claim 1, characterized in that Also includes: The deposition time of the deposition is adjusted to control the thickness of the aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate.

4. The method according to claim 3, characterized in that Also includes: During the deposition process, the silicon carbide substrate is controlled to rotate so as to uniformly deposit the aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate.

5. The method according to claim 4, characterized in that Also includes: During the deposition process, the aluminum target and the titanium target are controlled to rotate so that the laser can bombard the aluminum target and the titanium target uniformly.

6. The method according to claim 1, characterized in that The step of brazing the butted silicon carbide substrates comprises: Placing the butted silicon carbide substrates in a brazing furnace under vacuum conditions; Controlling the brazing furnace to heat up to a predetermined temperature and maintaining the temperature so that the aluminum phase in the aluminum-titanium nanoparticle layer reacts with the silicon carbide matrix to form a nanoparticle connection layer containing a Ti3Si(Al)C2 phase; The brazing furnace is cooled to obtain the silicon carbide substrate connected as one body.

7. The method according to claim 6, characterized in that The step of controlling the brazing furnace to heat up to a predetermined temperature and keeping the temperature constant comprises: Controlling the brazing furnace to heat up to a first predetermined temperature; After the brazing furnace is kept at the first predetermined temperature for a first predetermined time, the brazing furnace is controlled to continue to heat up to a second predetermined temperature and keep the temperature for a second predetermined time.

8. The method according to any one of claims 1 to 7, characterized in that The thickness of the aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate is 10 to 30 μm.

9. The method according to any one of claims 1 to 7, characterized in that In the aluminum-titanium nanoparticle layer on the surface of the silicon carbide substrate, the atomic percentage of aluminum is 50 to 100 at %.

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