Thermal fatigue resistance of open cell ceramic foams

A variety of open cell ceramic foams were subjected to rapid thermal cycles by infrared heating and forced air cooling to study the thermal fatigue behaviour of these materials. After cycling, the extent of damage in the samples was determined by measuring the elastic modulus using dynamic resonance (non-destructive test) and the retained strength in three-point bending (destructive test). It was found that the retained elastic modulus and strength gradually decreased with an increase in the number of cycles, followed by a saturation behaviour indicating a damage accumulation mechanism. The extent of damage was found to depend on the cellular structure parameters (i.e. cell size and density), composition, as well as thermal cycling variables, such as maximum temperature, cooling rate, etc.