Vickers indentation anisometry on thin cylindrical materials

Abstract

The required anisometric correction to be made when using Vickers indentations on filaments with radial dimensions of the order of those of the microindenter, is evaluated. For an isotropic plastic material the anisometry of indentation. Δl=l∥{-l ₁ increases with decreasing cross-section of the filament. If the calculated correction, Δ/^c, is in agreement with experiment the interest lies in the fact that the material preserves the indentation shape after removal of the indenter. Values of Δ/≠Δ/^c reveal the presence of a mechanical anisotropy on metallic filaments due to processing. Furthermore, in the case of thin highly oriented polymeric fibres the inherent microindentation anisotropy is masked by the anisometry effect. Consequently, the proposed correction is very important and particularly valuable when anisotropic cylindrical material surfaces are being studied.