Abstract
Residual strain profiles in friction-stir processed (FSP) AZ31B magnesium-alloy plates were
measured using neutron diffraction. Two different specimens were prepared to investigate the
influences of the tool shoulder and the tool pin on the residual-strain profiles: (Case 1) a plate
processed with both the stirring pin and tool shoulder, i.e., a regular FSP plate subjected to both the
plastic deformation and frictional heating, and (Case 2) a plate processed only with the tool
shoulder, i.e., subjected mainly to the frictional heating. The results show that the strain profiles of
both cases are qualitatively quite similar. The longitudinal strain is mainly tensile with its
maximum near the bead of the FSP plate. On the other hand, the transverse and normal strains are
mildly compressive in both Cases 1 and 2.
