Qizhen Li

Abstract:

Magnesium is the lightest structural metal and its low density makes it highly attractive for automobile and aerospace industries. The usage of light weight magnesium based components in cars and airplanes can reduce the weight of these transportation vehicles and improve the fuel efficiency. To broaden the practical applications of magnesium, it is often needed to refine the material's microstructure and thus improve its mechanical properties. Among the various processing techniques for refining the microstructure of magnesium, equal channel angular pressing (ECAP) is one of the most widely used techniques. In this study, commercially pure magnesium was processed using a series of ECAP cycles and the cross-section planes of the ultrafine grained samples were observed to explore qualitatively the microstructure evolution and inhomogeneity generated through the processing. The observation shows that a large number of deformation twins were generated in most of the grains, shear bands and the breakdown of grains were observed in some portion of the sample, and there was more severe deformation for the part of the sample that travelled along the inner surface of the mold channel.