Microstructures and mechanical properties of brazed 6063 aluminum alloy joint with Al-Cu-Si-Ni filler metal

摘要

In this study, brazing experiments were carried out on 6063 aluminum alloy using Al-20Cu-5Si-2Ni filler alloy. Microstructure, mechanical property, and removing behavior of oxide film of the brazed joints were analyzed. The results revealed that the 3% (CsF-AlF3) + 97% (KF-AlF3) non-corrosive flux showed high activity, especially effective removal of oxide films during the brazing process. For the brazing condition of 580 degrees C/10 min, the brazing seam contained less CuAl(2)intermetallic compared with that of 570 degrees C/20 min and presented a higher shear strength of 126.1 MPa at room temperature. After heat treatment the joint strength was increased to 156.5 MPa. Furthermore, the heat-treated joints subjected to a salt spray test still retained a shear strength of 150.2 MPa.