Relationship between impact yield stress and indentation hardness

Abstract

Impact yield stresses for hard brittle substances can be related quantitatively to indentation hardnesses if it is assumed that both are governed by a critical shear stress criterion for the onset of rapid plastic flow. The critical shear stress τ_gp is related to the shear stiffness on the glide plane by τ_gp?0.043G_gp. Therefore, hardness measurements can be used to obtain low−temperature yield stresses for these materials and to estimate impact yield stresses.