Tensile and fatigue behavior of SZ, HAZ and BM in friction stir welded joint of rolled 6N01 aluminum alloy plate

Tensile and fatigue behavior of a 6N01 aluminum alloy friction stir welded (FSW) joint was studied. The tensile and fatigue tests were carried out for the large plate and small round bar specimens. The small round-bar specimens extracted from base material (BM), heat affected zone (HAZ) and stir zone (SZ). The HAZ exhibited the lowest hardness. The higher tensile and fatigue strengths of SZ were mainly due to fine and homogeneous grains and significant cyclic hardening. Fatigue failure of the large plate specimen including the whole FSW joint part occurred at the lowest hardness location in the HAZ.