Elastic modulus determined by Hertzian indentation

A new method for determining the elastic modulus from Hertzian contact experiments has been developed. The test surfaces are polished and coated with a thin layer of Au/Pd and then indented with a small sphere. The contact removes the coating from the contact area and the size of this can, therefore, be readily measured in an optical microscope. A simple analysis based on Hertz equations is then used to derive the modulus. The elastic moduli of glass and several ceramics (including Si sub 3 N sub 4 , Al sub 2 O sub 3 and Al sub 2 O sub 3 /SiC whiskers) are reported.