CN105499833A - High-temperature brazing material for brazing tungsten-copper alloy and copper or copper alloy and brazing method of high-temperature brazing material - Google Patents

Abstract

The invention discloses a high-temperature brazing material and a method thereof for brazing tungsten-copper alloys and copper or copper alloys. The brazing material provided is composed of the following components in weight percentage: Mn8.0%～ 12.0%, Co 2.0% to 4.5%, Ni 2.0% to 4.0%, Zr 2.5% to 4.5%, and the balance is Cu. The copper-based solder provided by the invention has moderate melting temperature and uniform solder melting, so that the solder has good wettability and spreadability to the base metal, and the brazed joint obtained has high strength and good corrosion resistance, and can be completely applied to In complex environments, it is an economical solder with good comprehensive performance.

Description

A high-temperature brazing material and brazing method for brazing tungsten-copper alloy and copper or copper alloy

technical field

The invention belongs to the technical field of heterogeneous material welding, and in particular relates to a high-temperature brazing material of tungsten-copper alloy and copper or copper alloy and a brazing method thereof.

Background technique

Tungsten-copper alloy combines the excellent properties of tungsten and copper. It not only has high thermal conductivity and low thermal expansion coefficient, but also exhibits good high-temperature strength, thermal shock resistance, ablation resistance and dimensional stability. It is often used as Used as high temperature resistant connectors, heat dissipation base parts, heat sink materials and contact materials. In actual use, tungsten-copper alloy as a contact material often needs to be integrated with copper or copper alloy with better conductivity, which requires that the connection part not only have good thermal conductivity, but also have high connection strength. Regarding the connection methods of tungsten copper alloy and copper or copper alloy, there are mainly sintering method, welding, screw connection and so on. Chinese patent 101009165 discloses a method for preparing integral electrical contacts connecting tungsten-copper alloys and copper tails: the integral connection is realized by adding a tungsten-copper alloy transition layer between the tungsten-copper alloy and copper or copper alloy copper tails. , the patented method adopts the process of preforming by pressing metal powder and then sintering at high temperature. The process is complex and requires high equipment. It does not involve the connection of formed tungsten-copper alloy parts, which is essentially different from the method provided by the present invention. Chinese patent 104588809A discloses a high-frequency welding method of tungsten copper or tungsten steel and brass: the brazing materials are Cu44.12%～56.45%, Ti10%～15%, Mg0.05～0.08%, Ag18～20 %, Mn15%～20%, Si0.5%～0.8%, the sum of Cu, Ti, Mg, Ag, Mn, Si content is 100% of thin strip copper-based solder for welding, the brazing used in this patent method The brazing material contains precious metal silver, the cost of the brazing filler metal is high, and the brazing filler metal contains Mg element, which will pollute the vacuum brazing equipment. The joint strength of the obtained tungsten copper and brass is 180-186MPa.

The present invention provides a high-temperature brazing method of tungsten-copper alloy and copper or copper alloy. Compared with the above two inventions, the present invention has the advantages of simple process, low cost of brazing material, high connection strength and wide application range.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a high-temperature brazing material of tungsten-copper alloy and copper or copper alloy and a brazing method thereof.

Technical solution: In order to solve the above technical problems, the present invention provides a high-temperature brazing material for brazing tungsten-copper alloy and copper or copper alloy. The high-temperature brazing material is composed of the following components by weight percentage: Mn8 .0% to 12.0%, Co2.0% to 4.5%, Ni2.0% to 4.0%, Zr2.5% to 4.5%, and the balance is Cu.

Further, the high-temperature brazing material is in the shape of a foil.

Further, the thickness of the high-temperature brazing material is 60-150 μm.

Above-mentioned high-temperature brazing method for brazing tungsten-copper alloy and copper or copper alloy, described high-temperature brazing method comprises the following steps:

(1) Preparation stage: Clean the end face of the tungsten-copper alloy, copper or copper alloy sample to be welded to remove impurities, oil stains and oxide films on the surface, use W40~W7 metallographic sandpaper to grind smooth, use W7 metallographic Grind and smooth both sides of the solder foil with sandpaper. After grinding, put the sample to be welded and the solder foil together in acetone, use ultrasonic cleaning for 15-20 minutes, and dry them;

(2) Assembling stage: place the cleaned solder foil between the tungsten-copper alloy and the copper or copper alloy surface to be welded, and fit it tightly in the special brazing fixture to ensure the accuracy of the connection, and place it on the fixture The indenter with rated mass produces a constant vertical pressure of 0.05-0.08MPa;

(3) Brazing connection stage: place the assembled fixture as a whole in a brazing equipment with a vacuum degree of not less than 1×10 ^-3 Pa, first raise the temperature to 300-350°C at a rate of 8-12°C/min, Keep warm for 15-20 minutes, then heat up to 700-850°C at a rate of 5-8°C/min, hold for 15-20 minutes, then continue to heat up to a brazing temperature of 960-1050°C at a rate of 6-10°C/min, and keep warm The time is 20-40min, then cooled to 800-850℃ at a rate of 10-15℃/min, the holding time is 10-15min, then cooled to 400-450℃ at a rate of 5-8℃/min, and finally cooled to At room temperature, the welding is completed; during the brazing process, the method of gradually increasing the temperature by multiple steps can effectively relieve the stress caused by the thermophysical properties such as thermal expansion coefficient and thermal conductivity and the shape of the connector when the tungsten-copper alloy is connected with copper and copper alloy dissimilar materials. Concentrate to improve the mechanical properties of joints.

The brazing material provided by the invention can make the brazing material have good brazing process performance, heat resistance and corrosion resistance and processing performance by adding a variety of alloy elements reasonably, and can meet the requirements of brazing joints between tungsten-copper alloy and copper or copper alloy in complex environments. performance requirements in . The addition of an appropriate amount of Mn element can improve the performance of the brazing joint through solid solution, and the second is that the addition of Mn can also improve the high temperature resistance of the joint to a certain extent; The generation of new phases can also change the shape of the phase constituent materials, and the refinement effect on specific phases is obvious; adding an appropriate amount of Ni can improve the heat and corrosion resistance and high temperature strength of the joint; adding an appropriate amount of Zr is beneficial to reduce the solder The melting point improves the fluidity of the alloy; at the same time, a large amount of Cu element is beneficial to improve the wettability and solid solution ability of the solder to the base metal, and improve the plasticity and strength of the alloy solder.

The brazing process provided by the invention is to first put the tungsten-copper alloy and copper or copper alloy into a special brazing fixture in a docking manner, and then put the sample and the fixture together into a vacuum furnace to complete the brazing, and the high vacuum environment cooperates Reasonable process parameter setting makes the whole component free from deformation, micro cracks, pores and inclusions and other defects, which helps to obtain brazed joints with good mechanical properties.

Beneficial effect: compared with the prior art, the present invention has the following advantages:

(1) The brazing temperature of the copper-based solder provided by the present invention is 960°C to 1050°C, the melting temperature of the solder is moderate, and the solder melts evenly. Through the beneficial interaction between the component contents, the solder has a positive effect on the base metal. With good wettability and spreadability, the obtained brazed joint has high strength and good corrosion resistance, and can be completely applied in complex environments. It is an economical solder with good comprehensive performance.

(2) The brazing process designed by the present invention is simple and reasonable, adopts the brazing method in a vacuum furnace, does not need to add flux and other protective measures during the brazing process, and the high vacuum environment cooperates with reasonable process parameter settings, so that the entire component has no deformation, There are no defects such as microscopic cracks, pores and inclusions, which help to obtain brazed joints with good mechanical properties.

(3) The copper-based solder provided by the present invention has excellent abnormal temperature and high temperature performance, and can fully undergo solid solution metallurgical reactions with the base metal. Using the simple and practical brazing process of the present invention can finally obtain a joint with good comprehensive performance.

Description of drawings

FIG. 1 is a structural schematic diagram of the brazing structural member in Embodiment 1. FIG.

detailed description

Example 1

Choose tungsten-copper alloy and copper for vacuum brazing of butt joints. Among them, the size of the tungsten-copper alloy and the copper sample is 20mm×20mm×5mm, and the surface to be brazed is 20mm×5mm.

The composition and mass percentage ratio of the solder are: Mn10.0%, Co3.0%, Ni3.5%, Zr2.5%, and the balance is Cu. The thickness of the solder is 60 μm.

The brazing process steps are:

(1) Preparation stage: Clean the end faces of the tungsten-copper alloy and red copper samples to be welded, remove impurities, oil stains and oxide films on the surface, use W40~W7 metallographic sandpaper to grind smooth, use W7 metallographic sandpaper Both sides of the material foil are ground and smoothed. After grinding, put the sample to be welded and the solder foil together in acetone, use ultrasonic cleaning for 15 to 20 minutes, and perform drying treatment;

(2) Assembly stage: place the cleaned solder foil between the tungsten-copper alloy and the surface of the copper to be welded, and fit it tightly in the special brazing fixture to ensure the accuracy of the connection. Pressure head, producing a constant vertical pressure of 0.05MPa;

(3) Brazing connection stage: place the assembled fixture as a whole in a brazing equipment with a vacuum degree of not less than 1×10 ^-3 Pa, first raise the temperature to 350°C at a rate of 12°C/min, hold it for 15min, and then Heat up to 800°C at a rate of 8°C/min, hold for 15 minutes, then continue to heat up to a brazing temperature of 1040°C at a rate of 10°C/min, hold for 30 minutes, then cool to 800°C at a rate of 12°C/min, The holding time is 15 minutes, then cooled to 450°C at a rate of 5°C/min, and finally cooled to room temperature with the furnace to complete the welding.

Results: As shown in Figure 1, the joint between the brazed tungsten-copper alloy and the copper was well formed. Metallographic observation showed that the brazed zone formed a dense interface bond, the alloy components were evenly distributed, and the four-point bending strength at room temperature was 710MPa.

Example 2

Choose tungsten copper alloy and brass for butt joint vacuum brazing. Among them, the size of the tungsten-copper alloy and the brass sample is 20mm×20mm×5mm, and the surface to be brazed is 20mm×5mm in section.

The composition and mass percentage ratio of the solder are: Mn12.0%, Co4.0%, Ni3.0%, Zr4.0%, and the balance is Cu. The thickness of the solder is 80 μm.

The brazing process steps are:

(1) Preparation stage: Clean the end faces of the tungsten-copper alloy and brass samples to be welded to remove impurities, oil stains and oxide films on the surface, use W40~W7 metallographic sandpaper to grind smooth, use W7 metallographic sandpaper to The two sides of the solder foil are ground and smoothed. After grinding, put the sample to be welded and the solder foil together in acetone, use ultrasonic cleaning for 15-20 minutes, and dry them;

(2) Assembly stage: place the cleaned solder foil between the tungsten-copper alloy and the brass surface to be welded, and fit it tightly in the special brazing fixture to ensure the accuracy of the connection, and place the rated mass on the fixture The pressure head produces a constant vertical pressure of 0.06MPa;

(3) Brazing connection stage: place the assembled fixture as a whole in a brazing equipment with a vacuum degree of not less than 1×10 ^-3 Pa, first raise the temperature to 300°C at a rate of 9°C/min, hold it for 15min, and then Heat up to 800°C at a rate of 7°C/min, hold for 15 minutes, then continue to heat up to a brazing temperature of 1000°C at a rate of 8°C/min, hold for 30 minutes, then cool to 800°C at a rate of 10°C/min, The holding time is 15 minutes, then cooled to 400°C at a rate of 7°C/min, and finally cooled to room temperature with the furnace to complete the welding.

Results: The tungsten-copper alloy and the brass joint obtained by brazing were formed well. Metallographic observation showed that the brazing zone formed a dense interface bond, the alloy components were evenly distributed, and the four-point bending strength at room temperature was 640MPa.

Example 3

Choose tungsten-copper alloy and copper for vacuum brazing of butt joints. Among them, the size of the tungsten-copper alloy and aluminum bronze samples is 20mm×20mm×5mm, and the surface to be brazed is 20mm×5mm in section.

The composition and mass percentage ratio of the solder are: Mn11.0%, Co3.5%, Ni3.0%, Zr4.5%, and the balance is Cu. The thickness of the solder is 100 μm.

The brazing process steps are:

(1) Preparation stage: Clean the end faces of the tungsten-copper alloy and aluminum bronze samples to be welded to remove impurities, oil stains and oxide films on the surface, use W40~W7 metallographic sandpaper to grind smooth, use W7 metallographic sandpaper to The two sides of the solder foil are ground and smoothed. After grinding, put the sample to be welded and the solder foil together in acetone, use ultrasonic cleaning for 15-20 minutes, and dry them;

(2) Assembly stage: place the cleaned solder foil between the tungsten-copper alloy and the aluminum bronze surface to be welded, and fit it tightly in the special brazing fixture to ensure the accuracy of the connection, and place the rated mass on the fixture The pressure head produces a constant vertical pressure of 0.07MPa;

(3) Brazing connection stage: place the assembled fixture as a whole in a brazing equipment with a vacuum degree of not less than 1×10 ^-3 Pa, first raise the temperature to 300°C at a rate of 8°C/min, hold it for 15min, and then Heat up to 800°C at a rate of 5°C/min, hold for 15 minutes, then continue to heat up to a brazing temperature of 980°C at a rate of 7°C/min, hold for 30 minutes, then cool to 800°C at a rate of 10°C/min, The holding time is 15 minutes, then cooled to 400°C at a rate of 6°C/min, and finally cooled to room temperature with the furnace to complete the welding.

Results: The brazed tungsten-copper alloy and the copper joint were formed well. Metallographic observation showed that the brazed zone formed a dense interface bond, the alloy components were evenly distributed, and the four-point bending strength at room temperature was 610MPa.

Example 4

Choose tungsten-copper alloy and copper for vacuum brazing of butt joints. Among them, the size of the tungsten-copper alloy and aluminum bronze samples is 20mm×20mm×5mm, and the surface to be brazed is 20mm×5mm in section.

The composition and mass percentage ratio of the solder are: Mn12.0%, Co2%, Ni4%, Zr3%, and the balance is Cu. The thickness of the solder is 100 μm.

The brazing process steps are:

(1) Preparation stage: Clean the end faces of the tungsten-copper alloy and aluminum bronze samples to be welded to remove impurities, oil stains and oxide films on the surface, use W40~W7 metallographic sandpaper to grind smooth, use W7 metallographic sandpaper to The two sides of the solder foil are ground and smoothed. After grinding, put the sample to be welded and the solder foil together in acetone, use ultrasonic cleaning for 15-20 minutes, and dry them;

(2) Assembly stage: place the cleaned solder foil between the tungsten-copper alloy and the aluminum bronze surface to be welded, and fit it tightly in the special brazing fixture to ensure the accuracy of the connection, and place the rated mass on the fixture The pressure head produces a constant vertical pressure of 0.07MPa;

(3) Brazing connection stage: place the assembled fixture as a whole in a brazing equipment with a vacuum degree of not less than 1×10 ^-3 Pa, first raise the temperature to 300°C at a rate of 8°C/min, hold it for 15min, and then Heat up to 800°C at a rate of 5°C/min, hold for 15 minutes, then continue to heat up to a brazing temperature of 980°C at a rate of 7°C/min, hold for 30 minutes, then cool to 800°C at a rate of 10°C/min, The holding time is 15 minutes, then cooled to 400°C at a rate of 6°C/min, and finally cooled to room temperature with the furnace to complete the welding.

Results: The brazed tungsten-copper alloy and the copper joint were formed well. Metallographic observation showed that the brazed zone formed a dense interface bond, the alloy components were evenly distributed, and the four-point bending strength at room temperature was 612MPa.

Example 5

Choose tungsten-copper alloy and copper for vacuum brazing of butt joints. Among them, the size of the tungsten-copper alloy and aluminum bronze samples is 20mm×20mm×5mm, and the surface to be brazed is 20mm×5mm in section.

The composition and mass percentage ratio of the solder are: Mn8.0%, Co4.5%, Ni2.0%, Zr4.5%, and the balance is Cu. The thickness of the solder is 100 μm.

The brazing process steps are:

(1) Preparation stage: Clean the end faces of the tungsten-copper alloy and aluminum bronze samples to be welded to remove impurities, oil stains and oxide films on the surface, use W40~W7 metallographic sandpaper to grind smooth, use W7 metallographic sandpaper to The two sides of the solder foil are ground and smoothed. After grinding, put the sample to be welded and the solder foil together in acetone, use ultrasonic cleaning for 15-20 minutes, and dry them;

(2) Assembly stage: place the cleaned solder foil between the tungsten-copper alloy and the aluminum bronze surface to be welded, and fit it tightly in the special brazing fixture to ensure the accuracy of the connection, and place the rated mass on the fixture The pressure head produces a constant vertical pressure of 0.07MPa;

(3) Brazing connection stage: place the assembled fixture as a whole in a brazing equipment with a vacuum degree of not less than 1×10 ^-3 Pa, first raise the temperature to 300°C at a rate of 8°C/min, hold it for 15min, and then Heat up to 800°C at a rate of 5°C/min, hold for 15 minutes, then continue to heat up to a brazing temperature of 980°C at a rate of 7°C/min, hold for 30 minutes, then cool to 800°C at a rate of 10°C/min, The holding time is 15 minutes, then cooled to 400°C at a rate of 6°C/min, and finally cooled to room temperature with the furnace to complete the welding.

Results: The brazed tungsten-copper alloy and the copper joint were formed well. Metallographic observation showed that the brazed zone formed a dense interface bond, the alloy components were evenly distributed, and the four-point bending strength at room temperature was 605 MPa.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (7)

1. the high-temperature brazing material for soldering tungsten-copper alloy and copper or copper alloy, it is characterized in that: described high-temperature brazing material is composed of the following components by weight percentage: Mn8.0% ~ 12.0%, Co2.0% ~ 4.5%, Ni2.0% ~ 4.0%, Zr2.5% ~ 4.5%, surplus is Cu.

2. the high-temperature brazing material for soldering tungsten-copper alloy and copper or copper alloy according to claim 1, is characterized in that: described high-temperature brazing material is foil-like.

3. the high-temperature brazing material for soldering tungsten-copper alloy and copper or copper alloy according to claim 1, is characterized in that: described high-temperature brazing material thickness is 60 ~ 150 μm.

4. the high-temp soldering method for soldering tungsten-copper alloy and copper or copper alloy according to claim 1, is characterized in that: described high-temp soldering method comprises the following steps:

(1) preparatory stage: sample tungsten-copper alloy to be welded, copper or copper alloy sample end face are cleared up, then grinding is carried out to sample end face smooth, to carry out grinding smooth by two-sided for brazing material paillon foil again, after grinding, sample to be welded and brazing material paillon foil are placed in acetone together, adopt Ultrasonic Cleaning 15 ~ 20min, and carry out drying and processing;

(2) assembling stage: the brazing material paillon foil after cleaning is placed between tungsten-copper alloy and copper or copper alloy welding surface, and be close to and be assemblied in special brazing jig, guarantee the precision connected, fixture is placed the pressure head of nominal-mass, produces the constant perpendicular pressure of 0.05 ~ 0.08MPa;

(3) the brazing stage: the fixture entirety assembled is placed in vacuum and is not less than 1 × 10 ^-3welding is completed in the brazing equipment of Pa.

5. the high-temp soldering method for soldering tungsten-copper alloy and copper or copper alloy according to claim 4, is characterized in that: adopt W40 ~ W7 abrasive paper for metallograph to grind to the grinding of sample to be welded in described step (1).

6. the high-temp soldering method for soldering tungsten-copper alloy and copper or copper alloy according to claim 4, is characterized in that: adopt W7 abrasive paper for metallograph to grind to brazing material paillon foil in described step (1).

7. the high-temp soldering method for soldering tungsten-copper alloy and copper or copper alloy according to claim 4, is characterized in that: the welding concrete steps in described step (3) are:

First with ramp to 300 ~ 350 DEG C of 8 ~ 12 DEG C/min, insulation 15 ~ 20min, again with ramp to 700 ~ 850 DEG C of 5 ~ 8 DEG C/min, temperature retention time 15 ~ 20min, continue to be warming up to brazing temperature 960 ~ 1050 DEG C with the speed of 6 ~ 10 DEG C/min again, temperature retention time 20 ~ 40min, 800 ~ 850 DEG C are cooled to again with the speed of 10 ~ 15 DEG C/min, temperature retention time 10 ~ 15min, 400 ~ 450 DEG C are cooled to again with the speed of 5 ~ 8 DEG C/min, finally cool to room temperature with the furnace, complete welding.