Elastic-Plastic Indentation of Hard, Brittle Materials with Spherical Indenters

A method was developed at the U.S. Bureau of Mines to measure the plastic deformation of hard, brittle materials with low values of elastic modulus to hardness ( E/H ). The method involves indenting the hard materials with spherical indenters and measuring the resulting contact diameter and depth. Subsequent analysis separates the plastic deformation from the elastic deformation. The analysis is an extension of a theoretical study of the indentation of ductile materials by spherical indenters. The analysis is based on Meyer's law and the results include the distribution of the contact pressure and the profile of the deformed surface. Measurements were made on alumina and WC–Co.