Abstract:
Vacuum contact reactive brazing was used to carry out connection test of 6A02 aluminum alloy with T2 copper foil as interlayer. Analysis method of SEM, energy spectrum and strength were adopted to analyze influence of brazing parameters on microstructure and mechanical properties of brazed joints. The results showed that when copper foil vacuum contact reactive brazing of 6A02 aluminum alloy was used, corrosion defects were easy to appear on both sides of brazed joints. Moreover, the higher connection temperature was and the longer holding time was, the more serious dissolution degree was. Common defects such as porosity and slag inclusion were not found in brazed joints, and dense brazed joints could be obtained by contact reactive brazing. When joining temperature was 560 ℃, microstructure of brazed joints consisted of 6A02 aluminum alloy, α-Al solid solution, CuAl
2 and Mg
2Si. When joining temperature was 570 ℃ and 580 ℃, short rod-shaped ω-FeCu
2Al
7 microstructure appeared in brazed joints, and microstructure appeared in brazed joints was 6A02 alloy, α-Al solid solution, CuAl
2, Mg
2Si and ω-FeCu
2Al
7. When joining temperature 570 ℃ and holding time was 30 min, the maximum shear strength of brazed joints was 38.5 MPa, and fracture was located in the brittle CuAl
2 reaction layer of 6A02 brazing seam.