Grain structure evolution during friction-stir welding of AZ31 magnesium alloy

The high-resolution electron back-scatter diffraction technique was employed to study the grain structure evolution during friction-stir welding of AZ31 magnesium alloy. The material flow was found to be a very complex process associated mainly with basal slip. The grain structure development was demonstrated to be dictated by the texture evolution but also to involve {101¯2} twinning, geometrical effects of strain and limited discontinuous recrystallization.