Investigation of Micro-deformation Behavior in Pure Magnesium and Magnesium Alloy Single Crystals Using Indentation Test

摘要

In a precious deformation processing, it is important to understand deformation behavior of magnesium because of its anisotropic properties. In this study, indentation tests were performed to pure magnesium, Mg-0.5at%Zn alloy and Mg-0.5at%Al alloy single crystals to investigate orientation dependence of micro-deformation behavior induced by the indentations. Two types of specimens with (0001) and (1210) surface were prepared. Using a steel spherical indenter, indentation tests were carried out at 4.9 N for 15 s at room temperature. The specimens were observed with an optical microscope. In pure magnesium, Mg-0.5at%Zn alloy and Mg-0.5at%Al alloy single crystals, when test planes were (0001), indentation forms were isotropic round shape. Slip lines and twins were scarcely observed. When test planes were (1210), indentation forms were elongated to [0001]. Basal slip and {10-12} twin were observed around the indentations. By alloying, indentation size on (0001) became small, but indentation size on (1210) scarcely changed.