銅単結晶におけるヌープ硬さとτ<SUB>III</SUB>の関係について

Abstract

The indentations on the cubic plane of Cu single crystals made at 77, 210 and 293°K by the conical indenter were compared with each other. The relationships were studied at 77, 210 and 293°K between the Knoop hardness measured along the various directions on the cubic plane of Cu single crystals and the behaviour of the tensile deformations of Cu single crystals with the tensile axes corresponding to those directions. The summary is as follows:(1) The shear stress-shear strain curves of Cu single crystals, whose tensile axes were close to the [001]-[011] boundary of stereographic triangle, were obtained at the strain rate \dotε\simeq10−2/sec at 77, 210 and 293°K. (2) At a lower temperature, the slip traces of the indentation generally showed less wavy appearance and were developed more remarkably along about 〈100〉 directions from the center of the indentation.(3) The orientation dependence of the Knoop hardness on the cubic plane of Cu single crystals was discussed in terms of the behaviour of the tensile deformation of Cu single crystals with the corresponding tensile axes. The temperature dependence of the resistance to indenting deformation seemed to vary with the directions of the short diagonal of the indenter on the cubic plane.(4) According as the deformation temperature was changed, there was a linear relationship between the Knoop hardness along each direction on the cubic plane and the τIII value of Cu single crystals with the tensile axis corresponding to that direction.