Knoop micro-hardness studies on (110) surface of gel grown strontium tartrate di-hydrate crystal

Abstract

The wedge shape or elongated pyramid Knoop indenter is preferred for micro-hardness anisotropy study. In the Knoop indenter, the width, volume or projected area of the indentation mark can be used as a measure of hardness by aligning the indenter along a particular direction of a surface. In the present study, the (110) surface of gel grown strontium tartrate di-hydrate crystal has been used for the Knoop micro-hardness study. The anisotropy of micro-hardness has been studied by changing the orientation of the Knoop indenter from 0º to 200º at a fixed load, which indicates one maximum and one minimum value of the Knoop micro-hardness. The variation of Knoop micro-hardness with applied load in the range of 5 g to 100 g load indicates three maxima of the Knoop micro-hardness values.