Thermal shock cracking in a metal-particle-reinforced ceramic matrix composite

We study thermal crack shielding and thermal shock damage in a double-edge cracked metal-particle-reinforced ceramic matrix composite subjected to sudden cooling at the cracked surfaces. Under severe thermal shocks, the crack will grow but will be bridged by the plastically stretched metal particles. A linear softening bridging law is used to describe the metal particle bridging behavior. An integral equation of the thermal crack problem incorporating the bridging effect is derived and the thermal stress intensity factor at the bridged crack tip is calculated numerically. It is found that the thermal stress intensity factor is significantly reduced by the metal particle bridging. While the crack growth in thermally shocked monolithic ceramics is unstable, the composite can withstand sufficiently severe thermal shocks without failure.