Aluminum and aluminum alloy and copper diffusion brazing process

Abstract

The invention discloses an aluminum and aluminum alloy and copper diffusion brazing process, and belongs to the field of dissimilar material connection. The process adopts Al-Si-Cu ternary alloy powder (the content of Si is 5%-7%, the content of Cu is 28%-30%, and the balance is Al, all in mass percent) as the connection materials, and under certain vacuum degree and certain pressure, heat is preserved at the temperature of 525-555 DEG C for 10-60 minutes, so connection between aluminum and aluminum alloy and copper can be realized. By adopting the method, liquid phase is formed by diffusion of Cu and Si atoms on an aluminum / oxidation film interface, and the oxidation film on the aluminum surface is removed, so as to realize metallurgical bonding, the joint is compact, the reliability is high, and the aluminum and aluminum alloy and copper diffusion brazing process is applicable to large area joint between pure aluminum and alloy thereof and copper and to welding of complex structural parts.

Description

technical field [0001] The invention relates to a diffusion brazing process of aluminum, aluminum alloy and copper, which belongs to the field of connection of dissimilar materials. Background technique [0002] Aluminum and copper are very common metals in daily life. Aluminum has a high content in the earth's crust, has a low density, and has good electrical and thermal conductivity. Copper's electrical and thermal conductivity is second only to silver. The joining of aluminum and aluminum alloys to copper is widely used in the power, chemical, refrigeration, transportation and aerospace industries. [0003] There are currently many problems in the connection of aluminum and aluminum alloys to copper. The thermal physical properties of aluminum and copper (melting point, linear expansion coefficient, thermal conductivity, heat of fusion) are very different, and there is a large thermal stress in the weld when direct welding, so the connection effect is very poor; the dire...

AI Technical Summary

Problems solved by technology

Although the flux is non-corrosive and does not need to be cleaned during the welding process, due to the flame brazing technology, the process operability requirements are high, and large-area bonding cannot be implemented, so its application range is narrow

[0007] In 2004, T.A.Mai and A.C.Spowage of the Singapore Institute of Manufacturing Technology used a 350WNd:YAG laser to realize the welding of 1mm thick pure copper and Al4047, analyzed the microstructure and microhardness at different welding rates, and determined the Al / Cu fusion The microhardness of the zone is high, and the results show that a large number of brittle intermetallic compounds are formed, and the joint strength is very poor

Since friction stir welding can usually only weld plates, its application range is narrow