Zirconium-containing brazing filler metal, method for preparing the same, and use thereof

Abstract

The application provides a zirconium-containing brazing filler metal and a preparation method and application thereof, and belongs to the technical field of brazing filler metals. The zirconium-containing brazing filler metal comprises the following raw materials: 40-60wt% of a brazing base material, 10-25wt% of Zr, 2-15wt% of Cr and the balance of Ni; the brazing base material is a nickel-based single crystal high-temperature alloy, and the nominal composition of the brazing base material is: 5.5-9.5wt% of Al, 0.5-5wt% of Cr, 5.5-12wt% of Mo, 1-4wt% of Re, 1-6wt% of Ta and the balance of Ni. The zirconium-containing brazing filler metal in the application is prepared by adding Zr, Cr and Ni on the basis of the brazing base material, and is suitable for brazing the nickel-based single crystal high-temperature alloy; the Zr is used as a melting point reducing element, has a large atomic radius and is not easy to diffuse into the base body, and is beneficial to ensuring that the base body has good uniformity.

Description

Technical Field

[0001] The present invention relates to the technical field of solder, and in particular to a zirconium-containing solder and a preparation method and application thereof. Background Art

[0002] Nickel-based single crystal high-temperature alloys are widely used as materials for the hot end components of aircraft engines due to their excellent high-temperature strength and corrosion resistance. Due to their precise and complex structures, the hot end components of aircraft engines often require high-quality connection methods. Vacuum brazing is a process that uses the melting and diffusion of solder in the weld under vacuum conditions to form a dense brazed joint. In order to enable brazing to be performed at a temperature that does not damage the parent material, a melting point reducing element needs to be added to the solder. Traditional solders usually use boron (B) as a melting point reducing element. Although the melting point reducing effect is good, B easily diffuses into the parent material. For example, a large amount of B will diffuse into the area near the weld to form a new phase, causing damage to the matrix, affecting the uniformity of the matrix structure, and even changing the matrix structure. Summary of the Invention

[0003] The purpose of the present invention is to provide a zirconium-containing brazing filler metal and a preparation method and application thereof. The zirconium-containing brazing filler metal provided by the present invention is used to braze nickel-based single crystal high-temperature alloys, and the matrix structure has good uniformity.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a zirconium-containing brazing filler metal, comprising the following preparation raw materials:

[0006] Brazing base material 40-60wt%, Zr10-25wt%, Cr2-15wt%, Ni balance;

[0007] The brazing base material is a nickel-based single crystal high-temperature alloy, and the nominal composition of the brazing base material is: Al5.5-9.5wt%, Cr0.5-5wt%, Mo5.5-12wt%, Re1-4wt%, Ta1-6wt%, and Ni as the balance.

[0008] Preferably, the nominal composition of the brazing base material is: Al 7.5wt%, Cr 1.5wt%, Mo 9.5wt%, Re 1.5wt%, Ta 3wt%, and Ni balance.

[0009] Preferably, the raw materials for preparing the zirconium-containing brazing filler metal include: 50wt% brazing base material, 15wt% Zr, 5wt% Cr, and the balance Ni.

[0010] Preferably, the particle size of the zirconium-containing solder is 100-300 mesh.

[0011] The present invention provides a method for preparing the zirconium-containing solder described in the above technical solution, comprising the following steps:

[0012] The raw materials for preparing the zirconium-containing solder are mixed, and mechanical alloying is achieved through ball milling to obtain the zirconium-containing solder.

[0013] Preferably, the particle size of the raw material is ≤74 μm.

[0014] Preferably, the ball-to-material ratio of the ball mill is 5 to 20:1, the rotation speed is 400 to 600 rpm, and the time is 6 to 15 hours.

[0015] Preferably, after the ball milling, the process further comprises: passing the obtained material through a 100-300 mesh sieve, and the material below the sieve is the zirconium-containing solder.

[0016] The present invention provides the use of the zirconium-containing brazing filler metal described in the above technical solution or the zirconium-containing brazing filler metal prepared by the preparation method described in the above technical solution in brazing of nickel-based single crystal high-temperature alloys, wherein the nominal composition of the nickel-based single crystal high-temperature alloy is: Al5.5~9.5wt%, Cr0.5~5wt%, Mo5.5~12wt%, Re1~4wt%, Ta1~6wt%, and Ni as the remainder.

[0017] Preferably, the brazing temperature is 1220-1280°C, the holding time is 20-120 min, and the vacuum degree is 1×10 -4 ~5×10 -3 Pa.

[0018] The present invention provides a zirconium-containing brazing filler metal, comprising the following raw materials: 40-60wt% brazing base material, 10-25wt% Zr, 2-15wt% Cr, and the balance Ni; the brazing base material is a nickel-based single crystal high-temperature alloy, and the nominal composition of the brazing base material is: 5.5-9.5wt% Al, 0.5-5wt% Cr, 5.5-12wt% Mo, 1-4wt% Re, 1-6wt% Ta, and the balance Ni. The zirconium-containing brazing filler metal of the present invention is prepared by adding Zr, Cr, and Ni to the brazing base material to adjust its composition. The zirconium-containing brazing filler metal is suitable for brazing nickel-based single crystal high-temperature alloys. Zr, as a melting point reducing element, has a large atomic radius and is not easily diffused into the matrix, thus ensuring good matrix uniformity and avoiding the adverse effect of using B as a melting point reducing element on matrix uniformity in the prior art.

[0019] The present invention provides a method for preparing the zirconium-containing solder, comprising the following steps: mixing the raw materials for preparing the zirconium-containing solder, and mechanically alloying the mixture through ball milling to obtain the zirconium-containing solder. When regulating the composition of the solder powder, the traditional method is to prepare the powder using argon atomization or rotating electrodes after smelting. For small-batch, multi-component composition control, the method of preparing the powder after smelting has a long production cycle, high cost, and is not conducive to precise composition control. The present invention adopts ball milling to prepare the zirconium-containing solder, which is convenient for rapid and precise modulation of the powder composition in small batches, simple operation, short production cycle, and is conducive to reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a scanning electron microscope photograph of the Zr-containing solder in Example 1;

[0021] Figure 2 This is a scanning electron microscope backscattered image of the weld structure formed after brazing in Example 2;

[0022] Figure 3 This is a microstructure photograph of the brazed joint formed after brazing in Example 2 after heat exposure;

[0023] Figure 4 This is a microstructure photograph of the brazed joint formed after brazing in Comparative Example 1 after heat exposure. DETAILED DESCRIPTION

[0024] The present invention provides a zirconium-containing brazing filler metal, comprising the following preparation raw materials:

[0025] Brazing base material 40-60wt%, Zr10-25wt%, Cr2-15wt%, Ni balance;

[0026] The brazing base material is a nickel-based single crystal high-temperature alloy, and the nominal composition of the brazing base material is: Al5.5-9.5wt%, Cr0.5-5wt%, Mo5.5-12wt%, Re1-4wt%, Ta1-6wt%, and Ni as the balance.

[0027] The raw materials for preparing the zirconium-containing brazing filler metal of the present invention include 40-60wt% of a brazing base material, preferably 45-55wt%, more preferably 48-52wt%, and even more preferably 50wt%. In the present invention, the brazing base material is a nickel-based single crystal high-temperature alloy, and the nominal composition of the brazing base material is: Al 5.5-9.5wt%, Cr 0.5-5wt%, Mo 5.5-12wt%, Re 1-4wt%, Ta 1-6wt%, and the balance is Ni. The nominal composition of the brazing base material is preferably: Al 6.5-8.5wt%, Cr 1-3wt%, Mo 8-11wt%, Re 1.3-2.5wt%, Ta 2-4wt%, and the balance is Ni. The nominal composition of the brazing base material is more preferably: Al 7.5wt%, Cr 1.5wt%, Mo 9.5wt%, Re 1.5wt%, Ta 3wt%, and the balance is Ni. In the present invention, the brazing base material is preferably prepared by a gas atomization method; wherein, the melting temperature is preferably 1500-1540°C, more preferably 1510-1530°C, and further preferably 1520°C; the diameter of the guide tube is preferably 3.5 mm; the atomization gas pressure is preferably 8-12 MPa, more preferably 9-11 MPa, and further preferably 10 MPa.

[0028] The raw materials for preparing the zirconium-containing brazing filler metal of the present invention include 10-25 wt% Zr, preferably 12-20 wt%, more preferably 14-18 wt%, and even more preferably 15 wt%. Zr is used as a melting point-reducing element in the present invention, as it has a large atomic radius and is less likely to diffuse into the matrix, thus ensuring good matrix uniformity.

[0029] The raw materials for preparing the zirconium-containing solder of the present invention include Cr2-15wt%, preferably 4-10wt%, more preferably 5wt%. The present invention uses Cr as an antioxidant, which is beneficial to improving the oxidation resistance of the zirconium-containing solder and the weld.

[0030] The raw materials for preparing the zirconium-containing solder in the present invention include Ni balance.

[0031] In the present invention, the particle size of the zirconium-containing solder is preferably 100-300 mesh, more preferably 200 mesh.

[0032] The present invention provides a method for preparing the zirconium-containing solder described in the above technical solution, comprising the following steps:

[0033] The raw materials for preparing the zirconium-containing solder are mixed, and mechanical alloying is achieved through ball milling to obtain the zirconium-containing solder.

[0034] In the present invention, the raw material for preparing the zirconium-containing brazing filler metal is preferably powder, and the particle size of the raw material is preferably ≤74μm; that is, the raw material for preparing the brazing base material powder, Zr powder, Cr powder and Ni powder, and the particle size of the brazing base material powder, Zr powder, Cr powder and Ni powder is preferably independently ≤74μm.

[0035] In the present invention, the ball-to-material ratio of the ball mill is preferably 5-20:1, more preferably 8-15:1, and further preferably 10:1; the rotation speed is preferably 400-600 rpm, more preferably 500-600 rpm; the time is preferably 6-15 h, more preferably 8-12 h, and further preferably 10 h.

[0036] In the present invention, the ball milling is preferably carried out in a planetary ball mill; in an embodiment of the present invention, the raw materials for preparing the zirconium-containing solder and ball milling beads are placed in a ball milling jar and ball milling is carried out on a planetary ball mill; the ball milling beads are preferably WC ball milling beads, and the ball milling jar is preferably a WC ball milling jar.

[0037] The present invention preferably mixes the raw materials for preparing the zirconium-containing brazing filler metal under the above conditions and performs ball milling. The brazing base material powder and the metal element powder (i.e., Zr powder, Cr powder, and Ni powder) can be mechanically alloyed by high-energy ball milling, which can make the uniformity of each component higher and obtain a brazing alloy powder (i.e., zirconium-containing brazing filler metal) with a lower melting point than that of a simple physical mixture, which is conducive to completing welding at the target welding temperature.

[0038] In the present invention, after the ball milling, the process preferably further comprises: passing the obtained material through a 100-300 mesh sieve (preferably a 200 mesh sieve), and the material below the sieve is the zirconium-containing solder.

[0039] The present invention provides the use of the zirconium-containing brazing filler metal described in the above technical solution or the zirconium-containing brazing filler metal prepared by the preparation method described in the above technical solution in the brazing of nickel-based single crystal high-temperature alloys. The nominal composition of the nickel-based single crystal high-temperature alloy is: Al5.5~9.5wt%, Cr0.5~5wt%, Mo5.5~12wt%, Re1~4wt%, Ta1~6wt%, and Ni as the balance. In the present invention, the nickel-based single crystal high-temperature alloy is preferably consistent with the composition of the brazing base material used in the preparation of the zirconium-containing brazing filler metal, which will not be repeated here. In the present invention, the brazing temperature is preferably 1220~1280℃, more preferably 1230~1250℃, and further preferably 1240℃; the holding time is preferably 20~120min, more preferably 30~60min, and further preferably 40min; the vacuum degree is preferably 1×10 -4 ~5×10 -3 Pa, more preferably 5×10 -4 ~1×10 -3 Pa.

[0040] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] Example 1

[0042] The raw materials for preparing the Zr-containing solder in this embodiment are: 50wt% brazing base material, 15wt% Zr, 5wt% Cr, and the balance Ni; each raw material is powder, wherein the brazing base material powder (prepared by gas atomization method, melting temperature 1520°C, guide tube diameter 3.5mm, atomization pressure 10MPa), Zr powder, Cr powder, and Ni powder have a particle size of ≤74μm;

[0043] The brazing base material is a nickel-based single crystal high-temperature alloy, and the nominal composition of the brazing base material is: Al7.5wt%, Cr1.5wt%, Mo9.5wt%, Re1.5wt%, Ta3wt%, and Ni as the balance;

[0044] After conversion, it can be known that the content of each element in the Zr-containing solder is Al3.75wt%, Cr5.75wt%, Mo4.75wt%, Re0.75wt%, Ta1.5wt%, Zr15wt%, and Ni as the balance.

[0045] The preparation method of the Zr-containing solder in this embodiment is as follows:

[0046] The brazing base material powder, Zr powder, Cr powder, Ni powder and WC ball milling beads are placed in a WC ball milling jar and ball milled on a planetary ball mill, wherein the ball-to-material ratio is 10:1, the rotation speed is 600 rpm, and the ball milling time is 10 hours; after the ball milling is completed, the WC ball milling beads are removed, and then the obtained material is passed through a 200-mesh sieve, and the sieve-free material is the Zr-containing solder.

[0047] Figure 1 This is a scanning electron microscope photograph of the Zr-containing solder in Example 1. The results show that lamellar and blocky particles are formed after ball milling.

[0048] Example 2

[0049] The brazing base material in Example 1 was brazed using the Zr-containing solder in Example 1, wherein the brazing temperature was 1240°C, the holding time was 40 min, and the vacuum degree was 5×10 -4 Pa.

[0050] Figure 2The scanning electron microscope backscattered image of the weld structure formed after brazing in Example 2 is shown in FIG. Figure 2 It can be seen that a dense brazed joint is formed after brazing, in which a small amount of granular hard phase exists. The hard phase is composed of enriched Zr, Cr, Mo and other elements (the γ phase in the weld is reduced, and the solubility of Zr, Cr, Mo and other elements is reduced, resulting in the enrichment of these elements); the enriched hard phase will become the crack initiation point, but the hard phases are not completely connected, which can prevent the expansion of the crack.

[0051] The brazed joint formed after brazing in Example 2 was subjected to tensile strength tests at room temperature (25° C.) and 980° C. The results showed that the tensile strength at room temperature was 616 MPa and the tensile strength at 980° C. was 586 MPa.

[0052] The brazed joint formed after brazing in Example 2 was exposed to 1000°C for 10 hours, and its microstructure is shown in the following figure. Figure 3 As shown, from Figure 3 It can be seen that the granular hard phase gradually increases in the brazed joint after heat exposure, but there is no obvious change in the matrix structure.

[0053] Comparative Example 1

[0054] The brazing base material described in Example 1 was brazed using commercially available B-containing brazing powder (prepared by gas atomization method, with a particle size of ≤74 μm); wherein the composition of the B-containing brazing powder in the solder is: B1wt%, Si3wt%, Ti7wt%, Al3wt%, Co9wt%, W4wt%, Cr11wt%, and Ni as the balance; the brazing temperature was 1240°C, and the holding time was 40 min.

[0055] The brazed joint formed after brazing in Comparative Example 1 was subjected to tensile strength tests at room temperature and 980°C. The results showed that the tensile strength at room temperature was 586 MPa and the tensile strength at 980°C was 516 MPa.

[0056] The brazed joint formed after brazing in Comparative Example 2 was exposed to 1000°C for 10 hours, and its microstructure is shown in the following figure. Figure 4 As shown, from Figure 4 It can be seen that there are a lot of white spots in the matrix on both sides of the weld after heat exposure, which is not conducive to the uniformity of the matrix structure.

[0057] Comparative Example 2

[0058] The brazing base material powder described in Example 1 was mixed with B powder having a particle size of ≤74 μm in a mass ratio of 98:2, and then ball-milled according to the method of Example 1 to obtain a B-containing solder;

[0059] The brazing base material described in Example 1 was brazed using the B-containing solder described above, where the brazing temperature was 1240°C, and the result showed that the brazing was not successful.

[0060] The above merely describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as falling within the scope of the present application.

Claims

1. A zirconium-containing brazing filler metal comprising the following raw materials: Brazing base material 40~60wt%, Zr 15~25wt%, Cr 2~15wt%, Ni balance; The brazing base material is a nickel-based single crystal high-temperature alloy, and the nominal composition of the brazing base material is: Al 5.5-9.5wt%, Cr 0.5-5wt%, Mo 5.5-12wt%, Re 1-4wt%, Ta 1-6wt%, and Ni balance.

2. The zirconium-containing brazing filler metal according to claim 1, wherein The nominal composition of the brazing base material is: Al 7.5wt%, Cr 1.5wt%, Mo 9.5wt%, Re 1.5wt%, Ta 3wt%, and Ni balance.

3. The zirconium-containing brazing filler metal according to claim 1 or 2, characterized in that: The raw materials for preparing the zirconium-containing solder include: 50wt% brazing base material, 15wt% Zr, 5wt% Cr, and the balance Ni.

4. The zirconium-containing brazing filler metal according to claim 1, wherein The particle size of the zirconium-containing solder is 100-300 mesh.

5. The method for preparing the zirconium-containing solder according to any one of claims 1 to 4, comprising the following steps: The raw materials for preparing the zirconium-containing solder are mixed, and mechanical alloying is achieved through ball milling to obtain the zirconium-containing solder.

6. The method for preparing zirconium-containing solder according to claim 5, characterized in that: The particle size of the raw material is ≤74 μm.

7. The method for preparing the zirconium-containing solder according to claim 5 or 6, characterized in that: The ball-to-material ratio of the ball mill is 5-20:1, the rotation speed is 400-600 rpm, and the time is 6-15 hours.

8. The method for preparing zirconium-containing solder according to claim 7, characterized in that: After the ball milling, the method further comprises: passing the obtained material through a 100-300 mesh sieve, and the material under the sieve is the zirconium-containing solder.

9. Use of the zirconium-containing brazing filler metal according to any one of claims 1 to 4 in brazing of nickel-based single crystal high-temperature alloys, wherein the nominal composition of the nickel-based single crystal high-temperature alloy is: Al 5.5-9.5wt%, Cr 0.5-5wt%, Mo 5.5-12wt%, Re 1-4wt%, Ta 1-6wt%, and Ni as the balance.

10. Use of the zirconium-containing brazing filler metal according to claim 9 in brazing nickel-based single crystal high-temperature alloys, characterized in that: The brazing temperature is 1220-1280°C, the holding time is 20-120 min, and the vacuum degree is 1×10 -4 ~5×10 -3 Pa.

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