FIRST MATRIX CRACKING BEHAVIOR OF CERAMIC COMPOSITES AT ELEVATED TEMPERATURES

摘要

The first matrix cracking behavior of a silicon carbide fiber (SCS-6(TM))-reinforced zircon matrix composite is studied as a function of flaw size and temperature. Flaws of controlled size are created in the monolithic zircon and silicon carbide fiber-reinforced zircon matrix composite by means of a Vicker's indentation technique. The first matrix cracking stress is measured at three different temperatures of 25, 500, and 1200℃ as a function of the crack length. The results on ceramic composites demonstrated both steady state and non-steady state matrix cracking behaviors and an increase in the steady state matrix cracking stress with an increase in temperature as predicted by the theoretical models. These results are compared with the predictions of the theoretical models of matrix cracking based on fracture mechanics analysis.