Durability of YZA ceramic foams in a porous burner

Abstract

The durability of YZA cellular ceramic foams was investigated in the demanding environment of an instrumented porous burner. Following exposure to the combustion environment, the ceramic foam coupons suffered moderate damage. Coupons exposed to extended duration tests in the burner did not show additional damage compared to coupons exposed to short duration tests indicating that damage occurred during start-up, when temperature gradients were most severe. To compare the results of the burner tests to conventional thermal shock experiments, samples were also exposed to a water quench test. Coupons removed from the burners and coupons exposed to the water quench from high temperatures exhibited similar failure morphologies. In both cases a marked transition in failure morphology was observed as the magnitude of the peak temperatures and thermal gradients were increased. Chemical analysis combined with these thermal shock measurements show that damage sustained by the foams in the burner results from thermal shock and not from chemical degradation.