Influence of rolling on internal friction peak of Mg-3Cu-1Mn alloy

The damping capacities of as-rolled Mg-3Cu-1Mn (CM31) alloy were studied by dynamic mechanical analyses. The internal friction in the first heating shows peaks P-1, P-2 and P-3 at 118, 190, and 320 degrees C, respectively. The significant peak P-3, which can not be found in the cast CM31 alloy, appears in the first heating Q(-1) curve and disappears in the second heating Q(-1) curve. The influence of rolling on the internal friction peaks of the CM31 alloy was investigated by optical microscopy, X-ray diffraction, and electron backscatter diffraction analyses. The results show that the textures are enhanced and the twins rapidly disappear while peak P-3 appears after deformation of the CM31 alloy, and confirm that the three internal friction peaks are the dislocation damping peak, grain boundary damping peak, and the recrystallization peak caused by twins, in the as-rolled CM31 alloy.