Evaluation of Sphere Indentation Damage and Residual Strength in Ceramics : SiC Sphere Indentation to SiC Specimen-Case of Elastic Condition

A silicon carbide sphere indentation was subjected to the surface of silicon carbide plate specimen to examine indentation damage patterns and residual strength of the specimen. After the residual strength of the damaged specimen was measured by the four-point flexural test, damage patterns were observed with the scanning electron microscope. In the case that the cone crack (equivalent to elastic damage) was the fracture origin, the residual strength was evaluated. A method of approximate analysis of cone crack taking account of mechanism of stable crack growth was proposed. The estimated values were almost in agreement with the measured values.