Comparison of high temperature mechanical properties of two monolithic SiC ceramics and an Al(sub 2)O(sub 3)/SiC composite

摘要

Fast fracture strength, slow crack growth, and creep properties have been evaluated for three ceramics in air at room temperature and two elevated temperatures. The ceramics are candidate materials for heat exchangers in fossil energy systems, therefore, retained strength after coal ash exposure was also measured. At 1100(degrees)C the ceramics had acceptable mechanical properties, but two of them exhibited strength loss due to coal ash corrosion. At 1400(degrees)C creep and slow crack growth were observed in two of the materials, and the material which exhibited best resistance to coal ash showed unacceptably high creep rates.