Palladium-nickel based filler metal for high-temperature brazing of ceramic materials and brazing method
By applying multi-active palladium-nickel-based solder, the problem of high-temperature connection of ceramic materials such as Si3N4 and SiC has been solved, achieving a stable connection effect of the joint at high temperature and reducing costs.
Patent Information
- Application Number
- CN202211264147.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-10-14
- Publication Date
- 2026-01-20
- Estimated Expiration
- 2042-10-14
AI Technical Summary
Existing technologies lack brazing fillers that can effectively connect ceramic materials such as Si3N4 and SiC or metals at high temperatures, and whose joints have a high temperature resistance of not less than 900℃.
A multi-active palladium-nickel-based brazing alloy is used, with the following composition: Nb: 8.0%–15.0%; Ti: 10.0%–18.0%; Zr: 5.0%–12.0%; Hf: 2.0%–6.0%; Ni: 20.0%–30.0%; Pd: balance. The brazing alloy matrix is a Pd60Ni40 eutectic composition. The alloy ingot is prepared by arc melting and then made into strip, sheet, or powder brazing alloy, which is then vacuum-brazed at high temperature between ceramics and metals.
It achieves a high temperature resistance of no less than 900℃ for the joint, improves the reliability and strength of ceramic-metal connection, and reduces the cost of brazing filler metal.
Smart Images
Figure CN115533241B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of welding technology, specifically relating to a multi-active component palladium-nickel-based brazing filler metal for high-temperature brazing of ceramic materials and a brazing method. Background Technology
[0002] Si3N4, SiC, and other ceramics are structural ceramic materials with excellent comprehensive properties, and they have important applications in heat engines, wear-resistant components, and heat exchangers. However, it is difficult to manufacture complex-shaped components using these ceramic materials through machining methods, and they can only be achieved through methods such as welding. Although AgCuTi brazing filler metal can achieve good interfacial bonding, the temperature resistance of the joint is limited and cannot match the high-temperature performance of the ceramic itself.
[0003] Currently, many high-temperature solder designs focus on Au, Pd, Pt, and Au-Pd-based solders, aiming for temperatures of 650℃ and above. For example, PdCoAuNiVSiB (patent CN200710087292.7) produces Si3N4 joints with a self-bonding strength of 250MPa–370MPa after soldering. This solder contains high levels of Pd and Au, two precious metals, making it expensive. Au-based solders Au-Ni-Cr-Fe-Mo and Au-Ni-V-Mo achieve high room-temperature joint strength, but the joint strength above 700℃ drops to 40% of the room-temperature strength (SD Peteves et al. Ceramic Transcations, 1997, 77:91).
[0004] In addition, Ni-Cr-Si brazing filler metal is also used for Si3N4 ceramic bonding in terms of improving high-temperature resistance without the presence of precious metal elements (Ali Mohammd Hadian et al. American Ceramic Society, 1996, 79(3): 659). The joint strength is stable at 700℃~900℃. However, the joints corresponding to this brazing filler metal have low room temperature strength and high brittleness. The brazing filler metal has poor practicality and is difficult to use for heterogeneous bonding of ceramics and metals.
[0005] In summary, there is still a lack of brazing filler metals that can be directly used for brazing Si3N4, SiC and other ceramics or in combination with metals, and whose joints have a high temperature resistance of not less than 900℃. Summary of the Invention
[0006] In view of the above-mentioned situation in the prior art, the object of the present invention is to provide a multi-active component palladium-nickel-based brazing filler metal for high-temperature brazing of ceramic materials and a brazing method. The present invention can improve the joint performance and achieve a joint high-temperature resistance of not less than 900℃.
[0007] According to one aspect of the present invention, a palladium-nickel-based brazing filler metal for high-temperature brazing of ceramic materials is provided, characterized in that the composition and content of the brazing filler metal are: Nb: 8.0%–15.0%; Ti: 10.0%–18.0%; Zr: 5.0%–12.0%; Hf: 2.0%–6.0%; Ni: 20.0%–30.0%; Pd: balance, and the content ratio of Pd to Ni is 3:2, that is, the brazing filler metal matrix is Pd. 60 Ni 40 Eutectic composition, wherein the percentage is a mass percentage.
[0008] According to another aspect of the present invention, a brazing method is provided for a palladium-nickel-based brazing filler metal for high-temperature brazing of the above-mentioned ceramic materials. The method includes: preparing raw materials according to the composition of the filler metal; then melting the raw materials into an alloy ingot using an arc melting method under argon protection; preparing a strip-shaped filler metal or a strip-shaped filler metal or a powdered filler metal; placing the prepared filler metal between ceramic / ceramic or ceramic / metal materials and then brazing it at high temperature in a vacuum furnace. The preferred brazing temperature is 1150℃~1300℃, with a holding time of 5~30 min. Furthermore, the preferred heating rate is 10℃ / min, and the vacuum degree inside the brazing furnace during the vacuum brazing process is preferably not less than 10%. -3 Pa. After brazing, the cooling rate from the brazing temperature to 500℃ should not exceed 5℃ / min, and then it can be furnace cooled to room temperature.
[0009] Furthermore, the strip-shaped solder is produced by a rapid cooling method (using a rapid-cooling foil preparation device), and the thickness of the solder foil is 80–150 micrometers. The sheet-shaped solder is prepared by wire cutting, and the thickness is 150–200 micrometers. The powdered solder is obtained by grinding the rapidly cooled foil into powder and then sieving it, with a powder particle size of less than 50 mesh.
[0010] The brazing filler metal system of the present invention can be used for high-temperature brazing of Si3N4 ceramics, SiC ceramics and their composites, SiBCN system ceramics and their composites, and the joint has a high temperature resistance of not less than 900℃. Attached Figure Description
[0011] Figure 1 These are electron microscope images of self-brazed SiC / SiC ceramic joints obtained using the brazing filler metal of Example 1 of the present invention.
[0012] Figure 2 These are electron microscope images of SiC / SiC ceramic self-pressure brazed joints obtained using the brazing filler metal of Embodiment 2 of the present invention;
[0013] Figure 3 The image is an electron microscope image of a SiC / SiC ceramic self-pressure brazed joint obtained using the brazing filler metal of Example 11 of the present invention. Detailed Implementation
[0014] To better understand the purpose, technical solution, and advantages of this invention, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.
[0015] This invention provides a multi-active component palladium-nickel-based brazing filler metal for high-temperature brazing of ceramic materials. The composition and content (mass percentage) of the filler metal are as follows: Nb: 8.0–15.0; Ti: 10.0–18.0; Zr: 5.0–12.0; Hf: 2.0–6.0; Ni: 20.0–30.0; Pd: balance, and the content ratio of Pd to Ni is 3:2, that is, the filler metal matrix is Pd. 60 Ni 40 Eutectic composition. Table 1 below lists examples of the palladium-nickel based solder of the present invention and the components and their weight percentages in each example.
[0016] Table 1: Composition of palladium-nickel based solders in Examples 1-11
[0017]
[0018]
[0019] The PdNi-based high-temperature solder of the above embodiments is prepared according to the following process route:
[0020] (1) Select high-purity Pd, Ni, Nb, Ti, Zr and Hf with a purity of not less than 99.0%, weigh them according to the weight ratio, and prepare the raw materials;
[0021] (2) The alloy was melted into alloy ingots by electric arc melting under argon protection;
[0022] (3) Prepare the solder using one of the following methods:
[0023] A. Rapidly cooled foil-like solder is prepared under argon protection using a rapid-cooling foil equipment. The foil thickness is 80–150 micrometers. Specifically, a single-roller rapid solidification equipment is used to prepare the rapidly cooled foil-like solder. For the single-roller rapid solidification process, the single roll needs to rotate at a high speed of 5000–12000 r / min. After the solder ingot melts and forms a liquid state, the cooling rate is between 10… 3 ~10 6 Between K / s.
[0024] B. After preparing the rapidly cooled foil-like brazing filler metal according to method A, grind the foil into powder using mechanical grinding, and then sieve the powder through a 50-mesh manual sieve. Obtain brazing filler metal powder with a particle size of less than 50 mesh.
[0025] C. Use wire cutting to cut the alloy ingot into sheet-like brazing filler metal with a thickness of 150-200 micrometers.
[0026] The brazing filler metal composition shown in Table 1 of Example 1 was used to prepare a 100-micron thick, rapidly cooled foil-like brazing filler metal with SiC ceramic / SiC ceramic joints. The vacuum brazing temperature was 1240°C, the holding time was 10 minutes, and the vacuum degree during the brazing and holding process was not lower than 10. -3 Pa; the heating rate is 10℃ / min, and the cooling process first lowers the temperature to 500℃ at a rate of 5℃ / min, and then cools it with the furnace to obtain a SiC / SiC ceramic self-brazed joint. The joint microstructure is as follows: Figure 1 As shown.
[0027] The brazing filler metal composition shown in Table 1 for Example 2 was prepared into a rapidly cooled foil strip with a thickness of 120 micrometers. This foil was then used to braze SiC ceramic itself. A stress of approximately 1 MPa was applied perpendicular to the welding surface. The vacuum brazing temperature was 1200°C, and the holding time was 30 minutes. During the brazing and holding process, the vacuum level was not lower than 10. -3 Pa; the heating rate is 10℃ / min, and the cooling process first lowers the temperature to 500℃ at a rate of 5℃ / min, and then cools it with the furnace to obtain a SiC / SiC ceramic self-pressure brazed joint. The joint microstructure is as follows: Figure 2 As shown.
[0028] The brazing filler metals used in Examples 3 and 4 in Table 1 were obtained as sheet-like filler metals with a thickness of 0.15 mm using wire cutting. The joints were Si3N4 / Si3N4 itself and SiC / SiC ceramic itself, respectively. The vacuum brazing temperature was 1260℃, and the holding time was 15 min. During the brazing and holding process, the vacuum degree was not lower than 10. -3 Pa; the heating rate is 10℃ / min, and the cooling process is first reduced to 500℃ at 5℃ / min, and then cooled with the furnace to obtain brazed joints of Si3N4 / Si3N4 and SiC / SiC ceramics.
[0029] The brazing filler metals used in Examples 5, 6, and 7, as shown in Table 1, were made into 0.15 mm quenched foil strips, ground, and sieved through a 50-mesh sieve to obtain brazing filler metal powder with a particle size of less than 50 mesh. This powder was then placed near the weld seams of Si3N4 ceramic / Kovar alloy, SiC ceramic / Kovar alloy, and SiBCN ceramic / Kovar alloy, respectively. Vacuum brazing was performed at 1220°C for 8 minutes, with a vacuum degree of no less than 10 kJ / m². -3 Pa; the heating rate is 10℃ / min, and the cooling process is first reduced to 500℃ at 5℃ / min, and then cooled with the furnace to obtain brazed joints of Si3N4 ceramic / Kova alloy, SiC ceramic / Kova alloy, and SiBCN ceramic / Kova alloy.
[0030] The solder compositions of Examples 8, 9, and 10 shown in Table 1 were used to fabricate a 120-micron-thickness quenched foil strip, with the joints being SiBCN ceramic itself and C... f / SiBCN ceramics themselves, and SiC f The SiBCN ceramic itself is used to form a sandwich structure by placing the brazing foil between the ceramic materials to be brazed. The vacuum brazing temperature is 1280℃, and the holding time is 20 minutes. During the brazing and holding process, the vacuum degree is not lower than 10. -3 Pa; the heating rate is 10℃ / min, and the cooling process first lowers the temperature to 500℃ at a rate of 5℃ / min, then cools it with the furnace to obtain SiBCN ceramic itself, C f / SiBCN ceramics themselves, and SiC f / SiBCN ceramic self-brazing joint.
[0031] The brazing filler metal composition shown in Table 1 for Example 11 was prepared into a rapidly cooled foil strip with a thickness of 120 micrometers. This foil was then used to braze SiC ceramic. A stress of approximately 1.5 MPa was applied perpendicular to the welding surface. The vacuum brazing temperature was 1150°C, and the holding time was 30 minutes. During the brazing and holding process, the vacuum level was not lower than 10. -3 Pa; the heating rate is 10℃ / min, and the cooling process first lowers the temperature to 500℃ at a rate of 5℃ / min, then cools it with the furnace to obtain a SiC ceramic / SiC ceramic brazed joint. The joint microstructure is as follows: Figure 3 As shown.
[0032] The solder system of this invention is based on Pd-40Ni eutectic composition and contains four active components: Nb, Ti, Zr, and Hf. Utilizing the Pd-Ni eutectic, the solder melting temperature is reduced while mitigating joint brittleness, which helps alleviate residual stress in the heterojunction joint between silicon nitride ceramic and metal, thus improving joint reliability. The use of multiple active components allows for simultaneous participation in the interfacial reaction with the ceramic, avoiding joint brittleness caused by the formation of a single brittle phase through the interfacial reaction of a single active component. Nb, Ti, Zr, and Hf, as transition metal elements, react with Si3N4 ceramic to form transition metal nitrides NbN, TiN, ZrN, and HfN, and react with SiC to form NbC, TiC, ZrC, and HfC. These transition metal carbonitrides have the same crystal lattice configuration and can form composite ceramic phases or high-entropy ceramic phases, improving joint performance.
Claims
1. A palladium-nickel-based brazing filler metal for high-temperature brazing of ceramic materials, characterized in that... The composition and content of the solder are as follows: Nb: 8.0%–15.0%; Ti: 10.0%–18.0%; Zr: 5.0%–12.0%; Hf: 2.0%–6.0%; Ni: 20.0%–30.0%; Pd: balance, and the content ratio of Pd to Ni is 3:2, that is, the solder matrix is Pd. 60 Ni 40 Eutectic composition, where the percentage is by mass.
2. A brazing method using palladium-nickel based brazing filler metal for high-temperature brazing of ceramic materials according to claim 1, the method comprising: Prepare the raw materials according to the composition of the brazing filler metal; Then, under argon protection, the raw materials are melted into alloy ingots using an electric arc melting method. Prepare the brazing filler metal into strips, sheets, or powders; place the prepared brazing filler metal between ceramics / ceramics or ceramics / metals and then braze it at high temperature in a vacuum furnace.
3. The method according to claim 2, wherein the high-temperature brazing temperature is 1150℃~1300℃, and the holding time is 5~30min.
4. The method according to claim 3, wherein the heating rate is 10°C / min, and the vacuum degree inside the brazing furnace is not less than 10°C during the holding process. -3 Pa.
5. The method according to claim 2, wherein the cooling rate during the process of reducing the temperature from the brazing temperature to 500°C after brazing is completed is no greater than 5°C / min, and then the furnace is cooled to room temperature.
6. The method according to claim 2, wherein the strip solder is prepared by a rapid cooling method, and the thickness of the solder foil is 80-150 micrometers.
7. The method according to claim 6, wherein when preparing the rapidly cooled foil using the single-roller method for rapid solidification, the rotational speed of the single roll is 5000–12000 r / min, and the cooling rate after the brazing filler metal ingot melts and forms a liquid state is between 10 and 10. 3 ~10 6 Between K / s.
8. The method according to claim 2, wherein the sheet solder is prepared by wire cutting and has a thickness of 150 to 200 micrometers.
9. The method according to claim 2, wherein the powdered brazing filler metal is obtained by grinding a rapidly cooled foil strip into powder and then sieving it, and the powder particle size is less than 50 mesh.