Ni₃Nb単結晶のヌープ硬さの異方性

抄録

The shear system of Ni₃Nb was studied by the measurement of anisotropy in the Knoop hardness on the (100), (010) and (001) surface planes of a single crystal. The hardness varied remarkably with changing crystal plane and indenter direction. From the deformation traces around indentations, several shear systems were assumed. The orientation dependence of the Schmid factor for the shear systems assumed were computed. The hardness anisotropy was explained in terms of four operative shear systems. They were (010)[001], (010)[100], {211}⟨‾10 7 13⟩ and {101}⟨10\bar1⟩, and the resolved shear stress is considered to increase in this order. It was supposed that the shear mode for the two (010) systems was due to slipping and that for the rest systems was due to twinning.