Medium-temperature high-strength aluminum alloy powder solder and preparation method thereof

Abstract

The invention discloses medium-temperature high-strength aluminum alloy powder solder, comprising the following components by weight: 6.0-8.5% of Si, 10.0-12.0% of Cu, 3.0-4.0% of Ge, 3.0-4.0% of Ni, 0.5-0.8% of La and the balance of A1. The invention also discloses a method for preparing the medium-temperature high-strength aluminum alloy powder solder by adopting a melt rapid cooling technology. The melting temperature range of the solder disclosed by the invention is 515-539 DEG C, and the brazing temperature is 545-560 DEG C. The solder is suitable for the brazing the aluminum alloy of which a solidus is higher than 560 DEG C, especially suitable for the heat-treatable strengthening aluminium alloy which is subjected to a solution treatment after being brazed and is of the solution temperature no more than 545 DEG C. The solder is also suitable for furnace brazing, vacuum brazing, induction brazing, torch brazing, and the like. The solder disclosed by the invention is adopted to be matched with QJ201 brazing flux for brazing the 6061 aluminum alloy in a furnace; after being brazed, the 6061 aluminum alloy is subjected to a T6 heat treatment; and the shear strength of a brazing joint is more than 94MPa.

Description

technical field [0001] The invention relates to an aluminum alloy brazing material, in particular to a medium-temperature high-strength aluminum alloy powder brazing material and a preparation method thereof. Background technique [0002] Aluminum alloy has excellent characteristics such as high specific strength, good corrosion resistance, easy forming, and good electrical and thermal conductivity. It is widely used in aerospace, shipbuilding, power transmission, petrochemical, automobile, electronics and other fields. Brazing has the advantages of small deformation of brazing parts and beautiful brazing seam, and is one of the most commonly used methods for aluminum alloy connection. [0003] The most widely used solder for aluminum alloy brazing is Al-Si based solder, which is based on Al-Si eutectic composition (Al-12.6Si). This eutectic alloy has good wettability, fluidity, brazing Corrosion resistance and machinability of welded joints, and high strength of brazed joi...

AI Technical Summary

Problems solved by technology

At present, the brazing temperature of the most widely used Al-Si brazing material for aluminum alloy brazing is 600-605°C, which is close to the solidus of 6063 and 6061 aluminum alloys (the solidus of 6063 aluminum alloy is 615°C, and the solidus of 6061 is 593°C. ℃), it is very easy to cause the grain growth of 6063 and 6061 aluminum alloy base metals, and it is also easy to cause the aluminum alloy base metal to melt into the solder to cause dissolution defects, which affects the performance of the brazed joint, so the Al-Si based solder cannot meet the requirements. Brazing requirements for 6063 and 6061 aluminum alloys

[0006] Other existing Al-Si-Cu series and Al-Si-Mg series aluminum alloy solders cannot meet the brazing requirements of 6063 and 6061 aluminum alloys, such as the melting temperature of typical Al-Si-Cu series solder BAl67CuSi The range is 525-535°C, and the Cu content is 27-29wt.%. Excessive Cu content will make the material brittle and cause corrosion of the base metal during brazing. It is difficult to obtain a brazed joint with excellent performance.