TiZrHfSi high-temperature brazing filler metal and preparation method thereof

Abstract

The application discloses a TiZrHfSi high-temperature brazing filler metal and a preparation method thereof. The TiZrHfSi high-temperature brazing filler metal is prepared by mixing Ti, Zr, Hf and Si element powders, ball-milling, and then uniformly mixing with a binder to form a paste-like brazing filler metal. The high-temperature brazing filler metal aims at connecting C / C composite materials, and the connected part after brazing can be used under high-temperature harsh conditions, thereby prolonging the service life of the material.

Description

TECHNICAL FIELD

[0001] The present application relates to a TiZrHfSi high-temperature solder and a preparation method thereof. BACKGROUND

[0002] C / C composite material is the only lightweight engineering material which can maintain high strength above 2200℃ due to its low density, high specific strength, high specific modulus, low thermal expansion coefficient, ablation resistance, heat shock resistance, high thermal conductivity and a series of excellent characteristics, and is widely used in aerospace and other fields. Since the sublimation temperature of carbon is very high, ordinary melting welding method is not suitable for use, and vacuum brazing technology is one of the mature part connecting technologies, brazing has little influence on the physical and chemical properties of the base material, and has little influence on the welding stress and deformation, and can weld different kinds of metals with different weldability, and is widely used in mechanical, motor, radio and other departments, and the manufacturing of microwave waveguide, electronic tube and electronic vacuum device also needs brazing technology.

[0003] The common high temperature brazing filler metals are mainly divided into four categories: nickel-based brazing filler metal, silver-based brazing filler metal, copper-based brazing filler metal and other brazing filler metals. The nickel-based brazing filler metal has high strength, excellent corrosion resistance and high temperature oxidation resistance, and a large number of grades have been formed, such as BNi-2, BNi-5, BNi-7 and Ni48PdCrBSi, and the use temperature of the nickel-based brazing filler metal is about 1100 DEG C. The silver-based brazing filler metal has good plasticity, high strength, excellent corrosion resistance and weldability, and is mainly composed of Ag-Cu, Ag-Mn and Ag-Ni, and Zn, Sn, In, Ga, Li and P are added to form a relatively low-cost, high-performance multi-element alloy brazing filler metal, and the use temperature of the silver-based brazing filler metal is 550-850 DEG C. Compared with the nickel-based brazing filler metal, the copper-based brazing filler metal has moderate melting temperature, good plasticity and brazing property, and is also one of the commonly used brazing filler metals for complex welds. The copper-based brazing filler metal includes Cu-Ni system, Cu-Mn system and Cu-Ag system, and Mn, Zn, Sn, Co, Fe, Si, B and P are added to prepare ternary or even multi-element copper-based brazing filler metal, and the use temperature of the copper-based brazing filler metal is below 500 DEG C. Other brazing filler metals mainly include titanium-based brazing filler metal and gold-based brazing filler metal. The titanium-based brazing filler metal is one of the commonly used welding materials for brazing of titanium alloy and ceramic parts, and has very high activity due to the large amount of titanium. Especially when the titanium-based brazing filler metal is used to braze ceramics, a good welding interface can be formed by chemical reaction with the ceramics, thereby improving the welding strength. Common titanium-based active brazing filler metals include Ti-Ni system, Ti-Cu-Ni system and Ti-Zr-Ni-Cu system, and the use temperature of the titanium-based brazing filler metal is about 1000 DEG C. The gold-based brazing filler metal has low vapor pressure, high strength, excellent corrosion resistance, high temperature oxidation resistance and brazing property, and is mainly used for welding of key parts of aerospace engines. According to the melting temperature, the gold-based brazing filler metal can be divided into low temperature gold-based brazing filler metal, medium temperature gold-based brazing filler metal and high temperature gold-based brazing filler metal.

[0004] The patent relates to a TiZrHfSi high temperature brazing filler metal, which can be used for connecting C / C composite materials, and the use temperature after connection is 1400-1850 DEG C, compared with other brazing filler metals, the use temperature of the connecting part is greatly improved, and the use range of the material is expanded. SUMMARY

[0005] The patent relates to a TiZrHfSi high temperature brazing filler metal, which can be used for connecting C / C composite materials, and the use temperature after connection is 1400-1850 DEG C, compared with other brazing filler metals, the use temperature of the connecting part is greatly improved, and the use range of the material is expanded.

[0006] A TiZrHfSi high temperature brazing filler metal, characterized in that: the mole percentage of Ti element is 15-25%, the mole percentage of Zr element is 50-65%, the mole percentage of Hf element is 10-20%, and the mole percentage of Si element is 3-10%.

[0007] The TiZrHfSi high-temperature brazing filler metal is characterized in that the solidus temperature of the high-temperature brazing filler metal is 1400-1850 DEG C.

[0008] The TiZrHfSi high-temperature brazing filler metal is characterized in that the brazing filler metal comprises metal powder and a binder, wherein the total mass percentage of the four powders of Ti, Zr, Hf and Si is 75-95%, and the mass percentage of the binder polyethylene is 4-30%.

[0009] The preparation method of the TiZrHfSi high-temperature brazing filler metal is characterized in that after the metal powder is weighed, alcohol is added for ball milling, vacuum drying is carried out for 12 hours after ball milling, then the binder is added, and the paste-like high-temperature brazing filler metal is prepared after uniform stirring.

[0010] The preparation method of the TiZrHfSi high-temperature brazing filler metal is characterized in that the ball milling time of the metal powder is 24-36 hours, and the rotating speed is 180-210 r / min.

[0011] The application has the following advantages by adopting the above technical scheme:

[0012] (1) For those skilled in the art, the element selection of the alloy brazing filler metal is the key to whether the brazing filler metal can be used at high temperature. The solidus temperature of the high-temperature brazing filler metal in the application is 1400-1850 DEG C, which is higher than that of common brazing filler metals. Ti, Zr, Hf and Si are all active elements, which can react well with C / C composite materials on the interface, so that the connection is firm. In addition, the addition of Si element can also appropriately reduce the melting point of the brazing filler metal, so that the difficulty of the brazing process is reduced. The brazing filler metal can greatly improve the use temperature of the connecting piece, thereby expanding the use field of the connecting piece.

[0013] (2) The raw material of the high-temperature brazing filler metal is easy to obtain, and the preparation process is simple. The whole preparation process is green and environmentally friendly, no pollutants are generated, and the preparation process is simple. BRIEF DESCRIPTION OF DRAWINGS DETAILED DESCRIPTION

[0014] The application will be further described below in combination with specific examples, but the application is not limited to these examples.

[0015] Example 1

[0016] The application will be further described below in combination with specific examples, but the application is not limited to these examples.

[0017] Example 1

[0018] The embodiment provides a TiZrHfSi high-temperature brazing filler metal, which comprises metal powder and a binder, wherein the total mass percentage of Ti, Zr, Hf and Si powder is 80%, and the mass percentage of the binder polyethylene is 20%.

[0019] The preparation method of the high-temperature brazing filler metal comprises the following steps:

[0020] (1) Ti, Zr, Hf and Si metal powder with a purity of 99.99% is weighed according to the above-mentioned proportion, wherein the molar percentage of Ti element is 15%, the particle size is 5 μm, the molar percentage of Zr element is 60%, the particle size is 5 μm, the molar percentage of Hf element is 20%, the particle size is 5 μm, and the molar percentage of Si element is 5%, and the particle size is 5 μm.

[0021] (2) The weighed powder is put into a ball mill, alcohol is added, the ball-to-material ratio is 12:1, the rotating speed is 180 r / min, the ball milling time is 24 h, and after the ball milling is completed, the powder is dried for 12 h and sieved.

[0022] (3) The sieved powder and the polyethylene binder are weighed according to the above-mentioned mass proportion, mixed and uniformly stirred, and the required high-temperature brazing filler metal is obtained.

[0023] The embodiment takes the welding of the current C / C composite material as an example and provides a brazing method of the high-temperature brazing filler metal, which comprises the following steps:

[0024] (1) Pretreatment: 400#, 600# and 800# sandpaper are used to polish C / C composite materials, the C / C composite materials are put into an alcohol solution and subjected to ultrasonic cleaning for 40 min, then cleaned with deionized water and dried for use.

[0025] (2) Assembly: then, the configured alloy paste is coated on the surface of the C / C composite material with a thickness of 500 μm, a sandwich structure of the filled brazing filler metal between two C / C composite materials is formed, the welded structure is fixed, and then placed in a vacuum furnace.

[0026] (3) Brazing: during the brazing process, the vacuum degree is better than 2*10-3 Pa, the temperature is raised to 1200 DEG C at a speed of 8 DEG C / min, and the temperature is kept for 60 min.

[0027] (4) Cooling: the temperature is cooled to 850 DEG C at a speed of 5 DEG C / min, the temperature is kept for 20 min; then the temperature is cooled to 750 DEG C at a speed of 2 DEG C / min, the temperature is kept for 30 min; then the temperature is cooled to 500 DEG C at a speed of 2 DEG C / min, the temperature is kept for 80 min; finally, the temperature is cooled to room temperature with the furnace, and the welding is completed.

[0028] The result is: C / C composite material joint area forms good metallurgical bonding, and the brazing seam is fully filled. The shear strength is measured to be 38.0727 MPa by using a tensile testing machine for shear strength test according to GB / T11363-2008 “Brazed joint strength test method”.

[0029] Embodiment 2

[0030] The embodiment provides a TiZrHfSi high-temperature brazing filler metal, which comprises metal powder and a binder, wherein the total mass percentage of Ti, Zr, Hf and Si powders is 85%, and the mass percentage of the binder polyethylene is 15%.

[0031] The preparation method of the high-temperature brazing filler metal comprises the following steps:

[0032] (1) Ti, Zr, Hf and Si four kinds of metal powders with a purity of 99.99% are weighed according to the above-mentioned proportion, wherein the molar percentage of Ti element is 20%, the particle size is 5 μm, the molar percentage of Zr element is 50%, the particle size is 5 μm, the molar percentage of Hf element is 20%, the particle size is 5 μm, and the molar percentage of Si element is 10%, and the particle size is 5 μm.

[0033] (2) The weighed powder is put into a ball mill, alcohol is added for ball milling, the ball-to-material ratio is 12:1, the rotating speed is 180 r / min, the ball milling time is 24 h, and after the ball milling is completed, the powder is dried for 12 h and sieved.

[0034] (3) The sieved powder and the polyethylene binder are weighed according to the above-mentioned mass ratio, mixed and uniformly stirred, and the required high-temperature brazing filler metal is obtained.

[0035] The embodiment takes the welding of the current C / C composite material as an example and provides a brazing method of the high-temperature brazing filler metal, which comprises the following steps:

[0036] (1) Pretreatment: 400#, 600# and 800# sandpaper are used to polish the C / C composite material, which is then ultrasonically cleaned in an alcohol solution for 40 min, cleaned with deionized water and dried for use.

[0037] (2) Assembly: The prepared alloy paste is coated on the surface of the C / C composite material with a thickness of 500 μm to form a sandwich structure of the filling brazing filler metal between the two C / C composite materials, and the welded structure is fixed and placed in a vacuum furnace.

[0038] (3) Brazing: The vacuum degree is better than 2×10-3 Pa during the brazing process, the temperature is raised to 1200 ℃ at a speed of 8 ℃ / min, and the temperature is kept for 60 min.

[0039] (4) Cooling: cooling to 850℃ at a rate of 5℃ / min, holding for 20min; then cooling to 750℃ at a rate of 2℃ / min, holding for 30min; again cooling to 500℃ at a rate of 2℃ / min, holding for 80min; finally cooling to room temperature with the furnace, completing the welding.

[0040] The result is: the joint area of the C / C composite material forms a good metallurgical bond, the brazing seam is fully filled, the shear strength test is carried out by a tensile testing machine according to GB / T11363-2008 "Brazed joint strength test method", and the shear strength is measured as 29.3581MPa.

[0041] Example 3

[0042] The embodiment proposes a TiZrHfSi high-temperature filler metal, which comprises metal powder and a binder, wherein the total mass percentage of the four powders of Ti, Zr, Hf and Si is 85%, and the mass percentage of the binder polyethylene is 15%.

[0043] The preparation method of the high-temperature filler metal comprises:

[0044] (1) The four kinds of metal powders of Ti, Zr, Hf and Si with a purity of 99.99% are weighed according to the above-mentioned proportion, wherein the molar percentage of Ti element is 15%, the particle size is 5μm, the molar percentage of Zr element is 60%, the particle size is 5μm, the molar percentage of Hf element is 10%, the particle size is 5μm, and the molar percentage of Si element is 15%, the particle size is 5μm.

[0045] (2) The weighed powder is put into a ball mill, alcohol is added for ball milling, the ball-to-material ratio is 12:1, the rotation speed is 180r / min, the ball milling time is 24h, and after the ball milling is completed, the powder is dried for 12h and sieved.

[0046] (3) The sieved powder and the polyethylene binder are weighed according to the above-mentioned mass ratio, mixed and stirred uniformly, and the required high-temperature filler metal is obtained.

[0047] The embodiment takes the welding of the current C / C composite material as an example, and provides a brazing method of the high-temperature filler metal, which comprises the following steps:

[0048] (1) Pretreatment: the C / C composite material is polished by 400#, 600# and 800# sandpaper respectively, ultrasonic cleaning in an alcohol solution for 40min, then cleaned with deionized water, and dried for use.

[0049] (2) Assembly: the prepared alloy paste is coated on the surface of the C / C composite material with a thickness of 500μm, forming a sandwich structure of the filler brazing filler metal between the two C / C composite materials, and then the welded structure is placed in a vacuum furnace.

[0050] (3) Brazing: The vacuum degree during brazing is better than 2*10-3 Pa, the temperature is raised to 1200℃ at a speed of 8℃ / min, and the temperature is kept for 60 min.

[0051] (4) Cooling: The temperature is cooled to 850℃ at a speed of 5℃ / min, the temperature is kept for 20 min; then the temperature is cooled to 750℃ at a speed of 2℃ / min, the temperature is kept for 30 min; then the temperature is cooled to 500℃ at a speed of 2℃ / min, the temperature is kept for 80 min; finally, the temperature is cooled to room temperature with the furnace, and the welding is completed.

[0052] The result is that: a good metallurgical bond is formed in the joint area of the C / C composite material, the brazing seam is fully filled, the shear strength test is carried out by using a tensile testing machine according to GB / T11363-2008 "Brazed joint strength test method", and the shear strength is measured as 33.8450 MPa.

[0053] Example 4

[0054] The embodiment provides a TiZrHfSi high-temperature brazing filler metal, the brazing filler metal comprises metal powder and a binder, and the total mass percentage of Ti, Zr, Hf and Si four kinds of powder is 85%, and the mass percentage of the binder polyethylene is 15%.

[0055] The preparation method of the high-temperature brazing filler metal comprises the following steps:

[0056] (1) After the Ti, Zr, Hf and Si four kinds of metal powder with a purity of 99.99% are weighed according to the above-mentioned proportion, the molar percentage of the Ti element is 23%, the particle size is 5μm, the molar percentage of the Zr element is 52%, the particle size is 5μm, the molar percentage of the Hf element is 16%, the particle size is 5μm, and the molar percentage of the Si element is 9%, and the particle size is 5μm.

[0057] (2) The weighed powder is put into a ball mill, alcohol is added for ball milling, the ball-to-material ratio is 12:1, the rotating speed is 180r / min, the ball milling time is 24h, and after the ball milling is completed, the powder is dried for 12h and sieved.

[0058] (3) After the sieved powder and the polyethylene binder are respectively weighed according to the above-mentioned mass proportion, the powder and the binder are mixed and uniformly stirred, and the required high-temperature brazing filler metal is obtained.

[0059] The embodiment takes the welding of the current C / C composite material as an example, and provides a brazing method of the high-temperature brazing filler metal, which comprises the following steps:

[0060] (1) Pretreatment: the C / C composite material is polished by using 400#, 600# and 800# sandpaper respectively, is cleaned in an alcohol solution for 40 min through ultrasonic cleaning, is cleaned with deionized water, and is dried for standby use.

[0061] (2) Assembly: The configured alloy paste is then coated on the surface of the C / C composite material with a thickness of 500 μm, forming a sandwich structure of the filler brazing filler metal between two C / C composite materials. The welded structure is then placed in a vacuum furnace.

[0062] (3) Brazing: The vacuum degree during the brazing process is better than 2 x 10-3 Pa. The temperature is raised to 1200 °C at a rate of 8 °C / min, and the temperature is kept for 60 min.

[0063] (4) Cooling: The temperature is cooled to 850 °C at a rate of 5 °C / min, and the temperature is kept for 20 min. Then the temperature is cooled to 750 °C at a rate of 2 °C / min, and the temperature is kept for 30 min. Then the temperature is cooled to 500 °C at a rate of 2 °C / min, and the temperature is kept for 80 min. Finally, the temperature is cooled to room temperature with the furnace, and the welding is completed.

[0064] The result is that a good metallurgical bond is formed in the joint area of the C / C composite material, and the brazing filler metal is filled sufficiently. The shear strength test is carried out by using a tensile testing machine according to GB / T11363-2008 "Brazed joint strength test method", and the shear strength is measured to be 40.6910 MPa.

[0065] The above description is only the preferred embodiments of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made according to the technical essence of the present application to the above embodiments are within the scope of the technical scheme of the present application.

Claims

1. A TiZrHfSi high temperature brazing filler, characterized by: The brazing filler material comprises powder and binder, wherein the total mass percentage of the powder is 75-95%, the mass percentage of the binder polyethylene is 4-30%, the powder is composed of Ti, Zr, Hf and Si powders, the mole percentage of Ti element is 15-25%, the mole percentage of Zr element is 50-65%, the mole percentage of Hf element is 10-20%, and the mole percentage of Si element is 3-10%.

2. The TiZrHfSi high temperature brazing material according to claim 1, characterized in that The solidus temperature of the high-temperature brazing filler material is 1400-1850 DEG C.

3. The method for preparing TiZrHfSi high-temperature solder according to claim 1, characterized in that, After weighing the four powders, alcohol is added for ball milling, the ball milling time is 24-36 h, the rotating speed is 180-210 r / min, vacuum drying is carried out for 12 h after ball milling, then the binder is added, and the paste-like high-temperature brazing filler material is prepared after uniform stirring.