Preparation method of self-brazing material for welding aluminum-copper member

Abstract

The invention discloses a self-brazing material for welding an aluminum-copper member. The self-brazing material comprises the following components: 12-15 percent of fluoride (30-80 percent of aluminum fluoride, 5-35 percent of caesium fluoride and the balance of potassium fluoride), 0.01-0.3 percent of hafnium, 0.01-0.8 percent of germanium, 0.05-2 percent of nickel, 0.8-3 percent of copper, 5-17 percent of silicon and the balance of aluminum. The self-brazing material is prepared through the following steps of: smelting and atomizing the raw materials of hafnium, the germanium, the nickel, the copper, the silicon and the aluminum in a vacuum furnace into fine powder; and then uniformly mixing with the fluoride, pressing into a composite ingot, directly extruding the composite ingot into a yarn or pipe, and winding the yarn into a coil or cutting the pipe into a ring to obtain the self-brazing material. The self-brazing material disclosed by the invention has the advantages that trace elements of Ge and Hf are introduced on the basis of the traditional Al-Si-Cu-Ni alloy system brazing material, so that the brazing material smelting temperature is lowered, the burning loss of an aluminum base material during welding is favorably avoided, the strength and plasticity of the brazing material are improved, the mechanical property of a brazing joint is favorably improved, and the improvement of the plasticity of the brazing material can ensure that the production efficiency is increased.

Description

technical field [0001] The invention relates to a brazing filler metal for aluminum-copper and its alloy, in particular to a preparation method of a self-brazing filler metal for welding aluminum-copper components. Background technique [0002] 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 (such as 3003 aluminum alloy) and 6-series (such as 6061 aluminum alloy) high-strength aluminum alloys to manufacture all-aluminum structural parts to replace copper structural parts has become the development direction of the world's manufacturing industry. However, there are more and more welding problems for aluminum and copper components. [0003] The main problem in the welding of aluminum-copper components is not only that dense oxi...

AI Technical Summary

Problems solved by technology

However, the current aluminum-silicon self-brazing filler metal has some shortcomings: the silicon content in the filler metal is high, the filler metal is brittle, and the processability is poor; the melting point of the solder filler metal is high (solidus temperature 577 ° C, liquidus temperature above 600 ° C) , which is very close to the melting point of 3-series and 6-series high-strength aluminum alloys, and brazing is more difficult; the strength of brazing joints with brazing filler metals is low, which cannot meet the requirements of engineering applications