X-Ray diffraction study of tensile deformation in a bulk polycrystalline Ag-30 at. % Cd alloy

Abstract

X-ray diffraction techniques have been used to study plastic deformation in a polycrystalline Ag-30 at.% Cd alloy under tensile load. The positions and shapes of all (hkl) reflections were recorded using a parafocusing arrangement up to a maximum true strain of 0.265. The effects on the peak displacements caused by stacking faults and by macroscopic strains normal to the surface were distinguished. The longitudinal true stress in the surface layer evaluated by least square analysis was smaller than the macroscopic flow stress by an approximately constant amount over the whole range of strain (in accord with previous observations of a stress gradient near a free surface); the apparent rate of work hardening in the surface was equal to that for the specimen as a whole. The stacking fault probability α was approximately a linear function of strain and attained a maximum value of 7×10−3.