Abstract
The present paper describes effect of indenter materials on Hertzian cracking of alumina ceramics. Two kinds of alumina ceramics having different density and 4 kinds of sphere indenters with different elastic modulus were used for the experiment. The crack initiation during the indentation was detected with acoustic emission. Experimental data showed that the fracture behavior such as the fracture load, ring crack radius and indentation strength were different depending on indenter material. In order to investigate the effect of indenter materials on the fracture behavior, numerical simulation (FEM) and observation of the crack growth below the indented surface were carried out. As results, it was confirmed that the frictional resistance at the interface influenced on the ring crack radius and that cone crack length was different depending on fracture load.
