Mechanical performance of friction stir welded thick section 7050

Historically the friction stir welding (FSW) of 7xxx series materials has met several barriers of implementation. Previous work in FSW of 7xxx alloys has shown that unlike the rest of the aluminum alloy families, post weld microstructure experiences natural aging and behaves differently in terms of mechanical and corrosion performance. This has resulted in the need for post weld heat treatment to recover mechanical and corrosion properties in these alloys.

As typical aerospace applications require highly tempered 7xxx, this study performed FSW in 0.75” 7050 and compared the impact of various initial, with both standard and non-standard final temper trials on mechanical and corrosion properties of the weld. Results have shown that all welds have passed twice the standard stress corrosion cracking requirements and that the tempering history had varying degrees of success in recovering the post weld mechanical properties of the weld joints.