Mechanism of Strength Degradation for Hot Corrosion of α‐SiC

Sintered α‐SiC was corroded by thin films of Na 2 SO 4 and Na 2 CO 3 molten salts at 1000°C. This hot corrosion attack reduced room‐temperature strengths by as much as 50%. Strength degradation was proportional to the degree and uniformity of corrosion pitting attack as controlled by the chemistry of the molten salt. Extensive fractography identified corrosion pits as the most prevalent source of failure. The fracture strength was correlated with pit depth and could be roughly estimated from a simplified fracture mechanics treatment.