Effect of combinations between joining and heat treatment on properties of friction stir welds in 7050 aluminum alloys

In order to obtain high strength and stress corrosion cracking (SCC) resistance in friction stir welds of 7050 aluminum alloy extrusions, optimal combination of FSW, solution heat treatment (SHT) and aging has been investigated. The welds with the best combination, SHT, FSW and aging, had higher joint efficiency than the 80% of base metals and higher corrosion resistance of more than 400MPa. These stemmed from finely precipitation of η' phases. The welds prepared by the others combination showed poor SCC resistance.