CN111299897A - Preparation method of flexible welding wire of brittle aluminum-silicon-copper brazing filler metal - Google Patents

Abstract

The invention discloses a preparation method of a flexible welding wire of brittle aluminum-silicon-copper brazing filler metal. The present invention is a kind of mixed powder wrapped by a flexible material aluminum-silicon alloy outer skin, and the mixed powder is composed of brittle material aluminum-silicon-copper powder with a weight ratio of 10-100% and 0-90% aluminum flux powder well mixed. Specifically, the aluminum-silicon-copper brazing filler metal is atomized by vacuum smelting gas to prepare aluminum-silicon-copper powder; the aluminum-silicon-copper powder and aluminum flux powder are proportioned by weight and then put into a double planetary mixer to be fully stirred to obtain a mixed solution. powder; the aluminum-silicon brazing material is obtained by smelting, extruding, rolling and slitting to obtain the aluminum-silicon brazing material strip; the aluminum-silicon brazing material strip is put into the wire forming machine, passes through each roller in turn, and finally rolled into a The tubular welding wire is received into the winding machine; during the forming process of the welding wire, the mixed powder is added through a powder feeder, and the flexible tubular flux-cored welding wire is obtained by winding. The invention solves the problem that the aluminum-silicon-copper brazing material has poor processing and forming performance due to its high brittleness.

Description

A kind of flexible welding wire preparation method of brittle aluminum-silicon-copper solder

technical field

The invention relates to a preparation method of a flexible welding wire of brittle aluminum-silicon-copper brazing filler metal.

Background technique

Aluminum alloys are widely used in industrial production and social life. Due to their small specific gravity, good electrical and thermal conductivity, excellent castability, plasticity and machinability, aluminum alloys play an irreplaceable role in modern industrial materials. The use of 3-series and 6-series high-strength aluminum alloys to manufacture parts to replace the original copper structural parts has become the development direction of the world's manufacturing industry. However, there are more and more welding problems of copper-aluminum components.

At present, copper-aluminum components mostly use zinc-aluminum solder, aluminum-silicon solder or aluminum-silicon-copper solder for brazing connection, but there are some shortcomings. When copper-aluminum components are welded with zinc-aluminum solder, the welding joints are prone to electrochemical corrosion and have a short service life; the melting point of aluminum-silicon solder is relatively high, the solidus temperature is 577 ° C, the liquidus temperature is above 600 ° C, and the The melting points of the 3-series and 6-series high-strength aluminum alloys are very close, and it is very easy to over-burn during brazing; the aluminum-silicon-copper brazing filler metal has good corrosion resistance, but the brazing filler metal itself is brittle and has poor workability, making it difficult to process the filler metal into a disk. The welding wire or welding ring cannot meet the requirements of continuous automation and high-efficiency brazing.

SUMMARY OF THE INVENTION

The invention provides a flexible welding wire preparation method of brittle aluminum-silicon-copper brazing filler metal, which can overcome the technical deficiency that the existing aluminum-silicon-copper brazing filler metal is difficult to be processed into a welding wire due to its high brittleness.

In order to achieve the above purpose, the present invention provides the following technical solutions, a method for preparing a flexible welding wire of brittle aluminum-silicon-copper solder, which is characterized in that a mixed powder is wrapped by a flexible material aluminum-silicon alloy outer skin, and the mixed powder is made of a brittle material. Aluminium-silicon-copper powder is mixed with aluminium flux powder.

Preferably, the composition of the aluminum-silicon-copper powder is 15%≤copper≤30%, 3%≤silicon≤7%, 0≤nickel≤3%, and aluminum is the balance.

Preferably, the aluminum flux powder is composed of potassium fluoroaluminate powder and cesium fluoroaluminate powder.

Preferably, the mixed powder is fully mixed with 10%-100% of brittle material aluminum-silicon-copper powder and 0-90% of aluminum flux powder by weight.

Preferably, the composition of the aluminum-silicon alloy skin is 4.5%≤silicon≤13.0%, copper≤5.0%, magnesium≤2.0%, zinc≤3.0%, iron≤0.8%, manganese≤0.15%, titanium≤0.2%, Chromium≤0.15%, bismuth≤0.2%, aluminum is the balance.

Preferably, the content of the aluminum-silicon alloy skin is in the range of 20%-80%, and the content of the mixed powder is in the range of 20%-80%.

As preferably, the concrete preparation method is as follows:

(1) Prepare aluminum-silicon-copper powder by vacuum smelting and gas atomization with 15%-30% of copper, 3%-7% of silicon, 0%-3% of nickel, and the balance of aluminum;

(2) Put the aluminum-silicon-copper powder and the aluminum flux powder into the double-planetary mixer after proportioning by weight and fully stir to obtain the mixed powder;

(3) the aluminum-silicon brazing filler metal is obtained by the method of smelting, extruding, rolling and slitting to obtain the aluminum-silicon brazing filler metal strip;

(4) put the aluminum-silicon brazing material strip into the wire forming machine, pass through each roll in turn, and finally roll into a tubular welding wire and receive it into the winder;

(5) in the welding wire forming process, add the mixed powder obtained in step (2) through a powder feeder, and wind up to obtain a flexible tubular flux-cored welding wire;

(6) Through the drawing and reducing method, the flexible welding wire can be drawn to different sizes by a wire drawing machine.

Preferably, the above-mentioned brittle aluminum-silicon-copper solder can adjust the brazing performance of the wire by adjusting the ratio of the aluminum-silicon alloy outer skin and the aluminum-silicon-copper powder to the aluminum flux powder in the mixed powder.

The beneficial effects of the invention are as follows: the problem of poor processing and forming performance of the aluminum-silicon-copper brazing filler metal due to its own brittleness is solved, and a flexible aluminum-silicon-copper brazing filler metal wire is prepared, which satisfies the requirements of subsequent coiling or ring-making processing. requirements, suitable for continuous automation and high-efficiency brazing. The aluminum-silicon-copper flexible welding wire produced by the forming method can be directly used for the welding of copper-aluminum components without adding aluminum flux. The welding wire or welding ring can realize continuous automatic welding; and the brazing performance of the welding wire can be adjusted by adjusting the ratio of the aluminum-silicon alloy outer skin and the aluminum-silicon-copper powder and the aluminum flux powder in the mixed powder, which is simple and convenient, low-cost and high-efficiency .

Detailed ways

The present invention will be further described below.

Implementation Case 1

1. The aluminum-silicon-copper brazing filler metal with the composition of copper 26.0%-27.0%, silicon 4.5%-5.5%, and aluminum as the balance is prepared by vacuum melting and gas atomization to prepare aluminum-silicon-copper powder with a particle size of -120 mesh. .

2. Weigh the aluminum-silicon-copper powder and the aluminum flux powder in a weight ratio of 3:1, put them into a double planetary mixer and fully stir to obtain a mixed powder with an aluminum-silicon-copper powder content of 75%.

3. The aluminum-silicon brazing filler metal with the composition of silicon 11.0%-13.0% and aluminum as the balance is obtained by smelting, extrusion, rolling and slitting to obtain an aluminum-silicon brazing filler metal strip with a thickness of 0.20mm and a width of 10.0mm .

4. Use the steel strip method to prepare the tubular flux-cored welding wire, put the aluminum-silicon brazing material strip into the welding wire forming machine, pass through each roller in turn, and finally roll it into a tubular welding wire and receive it into the winder.

5. During the welding wire forming process, add the mixed powder obtained in step 2 through a powder feeder, control the added weight of the mixed powder to account for about 80% of the total weight of the welding wire, and wind up to obtain a flexible tubular flux core with a diameter of Ф3.2mm In the welding wire, the aluminum-silicon-copper powder accounts for 60%, the aluminum-silicon brazing filler metal skin accounts for 20%, and the aluminum flux powder accounts for 20%.

6. By drawing and reducing diameter, the flexible welding wire can be drawn to Ф3.0mm and smaller required size by wire drawing machine.

Implementation case 2

1. The aluminum-silicon-copper brazing filler metal with the composition of copper 26.0%-27.0%, silicon 4.5%-5.5%, and aluminum as the balance is prepared by vacuum melting and gas atomization to prepare aluminum-silicon-copper powder with a particle size of -120 mesh. .

2. Weigh the aluminum-silicon-copper powder and the aluminum flux powder in a weight ratio of 2:1, and put them into a double planetary mixer to fully stir to obtain a mixed powder with an aluminum-silicon-copper powder content of 67%.

3. Use the aluminum-silicon brazing filler metal whose composition is 11.0%-13.0% of silicon and aluminum as the balance to obtain aluminum-silicon brazing filler metal strips with a thickness of 0.25mm and a width of 6.5mm by smelting, extruding, rolling and slitting. .

4. Use the steel strip method to prepare the tubular flux-cored welding wire, put the aluminum-silicon brazing material strip into the welding wire forming machine, pass through each roller in turn, and finally roll it into a tubular welding wire and receive it into the winder.

5. During the welding wire forming process, add the mixed powder obtained in step 2 through a powder feeder, control the added weight of the mixed powder to account for about 60% of the total weight of the welding wire, and wind up to obtain a flexible tubular flux core with a diameter of Ф2.2mm In the welding wire, aluminum-silicon-copper powder accounts for 40%, aluminum-silicon brazing filler metal skin accounts for 40%, and aluminum flux powder accounts for 20%.

6. By drawing and reducing the diameter, the flexible welding wire can be drawn to Ф2.0mm and smaller required size by wire drawing machine.

Implementation Case 3

1. The aluminum-silicon-copper brazing filler metal with the composition of copper 26.0%-27.0%, silicon 4.5%-5.5%, and aluminum as the balance is prepared by vacuum melting and gas atomization to prepare aluminum-silicon-copper powder with a particle size of -120 mesh. .

2. Use the aluminum-silicon brazing filler metal whose composition is 11.0%-13.0% of silicon and aluminum as the balance, and obtain the aluminum-silicon brazing filler metal strip with a thickness of 0.35mm and a width of 10.0mm by smelting, extrusion, rolling and slitting. .

3. Use the steel strip method to prepare the tubular flux-cored welding wire, put the aluminum-silicon brazing material strip into the welding wire forming machine, pass through each roller in turn, and finally roll it into a tubular welding wire and receive it into the winder.

4. In the process of welding wire forming, add Al-Si-Cu powder separately through one powder feeder, and add Al-Si-Cu powder separately by another powder feeder. About 40% and 20% of the total weight, the flexible tubular flux-cored welding wire with a diameter of Ф3.2mm is obtained by winding up. The aluminum-silicon-copper powder in the welding wire accounts for 40%, the aluminum-silicon brazing filler metal skin accounts for 40%, and the aluminum flux powder accounts for 20%. %.

5. By drawing and reducing the diameter, the flexible welding wire can be drawn to the required size of Ф3.0mm and smaller by the wire drawing machine.

The forming method of the invention solves the problems of poor workability of the aluminum-silicon-copper brazing filler metal, and the brazing filler metal is difficult to be processed into a disc-shaped welding wire or a welding ring, and can realize continuous automation and high-efficiency welding. The aluminum-silicon-copper flexible welding wire produced by the forming method can be directly used for the welding of copper-aluminum components without adding aluminum flux. The welding ring can realize continuous automatic welding; and the brazing performance of the welding wire can be adjusted by adjusting the ratio of the aluminum-silicon alloy outer skin and the aluminum-silicon-copper powder and the aluminum flux powder in the mixed powder, which is simple and convenient, low in cost and high in efficiency.

The above are only the preferred embodiments of the present invention, and the new type of flexible welding wire can also be produced by the steel pipe method, the coiling method, etc. Under the premise, several improvements and modifications can also be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims (8)

1. A preparation method of a flexible welding wire of a brittle aluminum-silicon-copper brazing filler metal is characterized in that the flexible welding wire is processed by wrapping a mixed powder by a flexible material aluminum-silicon alloy sheath, and the mixed powder is formed by mixing a brittle material aluminum-silicon-copper powder and an aluminum brazing flux powder.

2. The method for preparing the flexible welding wire of the brittle aluminum-silicon-copper brazing filler metal according to claim 1, wherein the brittle aluminum-silicon-copper powder comprises 15% to 30% of copper, 3% to 7% of silicon, 0% to 3% of nickel and the balance of aluminum.

3. The method of claim 1, wherein the aluminum flux powder comprises potassium fluoroaluminate powder and cesium fluoroaluminate powder.

4. The method for preparing the flexible welding wire of the brittle aluminum-silicon-copper brazing filler metal according to claim 1, wherein the mixed powder is formed by fully mixing 10-100% by weight of brittle aluminum-silicon-copper powder and 0-90% by weight of aluminum brazing filler metal powder.

5. The method for preparing the flexible welding wire of the brittle aluminum-silicon-copper brazing filler metal according to claim 1, wherein the flexible material aluminum-silicon alloy sheath comprises 4.5% to 13.0% of silicon, 5.0% to copper, 2.0% to magnesium, 3.0% to zinc, 0.8% to iron, 0.15% to manganese, 0.2% to titanium, 0.15% to chromium, 0.2% to bismuth and the balance aluminum.

6. The method for preparing the flexible welding wire of the brittle aluminum-silicon-copper brazing filler metal according to claim 1, wherein the content of the aluminum-silicon alloy sheath ranges from 20% to 80%, and the content of the mixed powder ranges from 20% to 80%.

7. The method for preparing the flexible welding wire of the brittle aluminum-silicon-copper solder according to claim 4, wherein the method comprises the following steps:

(1) preparing aluminum-silicon-copper powder from 15-30% of copper, 3-7% of silicon, 0-3% of nickel and the balance of aluminum by a vacuum melting and gas atomization method;

(2) mixing aluminum-silicon-copper powder and aluminum brazing filler metal powder according to a weight ratio, and then putting the mixture into a double-planet stirrer for fully stirring to obtain mixed powder;

(3) the aluminum-silicon brazing filler metal is subjected to smelting, extruding, rolling and slitting to obtain an aluminum-silicon brazing filler metal strip;

(4) putting the aluminum-silicon brazing filler metal strip into a welding wire forming machine, sequentially passing through each roller, finally rolling into a tubular welding wire and taking the tubular welding wire into a winding machine;

(5) in the welding wire forming process, adding the mixed powder obtained in the step (2) through a powder adding device, and rolling to obtain a flexible tubular flux-cored wire;

(6) the flexible welding wire can be drawn to different sizes by a drawing and reducing method through a wire drawing machine.

8. The use of brittle Al-Si-Cu brazing filler metal is characterized in that the brazing performance of the welding wire is adjusted by adjusting the ratio of Al-Si-Cu powder to aluminum brazing filler metal powder in an Al-Si alloy sheath and mixed powder.