Patent ID: 8658291

Claim:
An environmental barrier coating (EBC) having CMAS mitigation capability comprising: a bond coat layer comprising silicon; an optional silica layer overlying the bond coat layer; at least one transition layer overlying the bond coat layer or the optional silica layer comprising a composition selected from the group consisting of mullite, barium strontium aluminosilicate (BSAS), and combinations thereof; an optional outer layer comprising BSAS overlying the at least one transition layer; a separate CMAS mitigation layer overlying the transition layer and overlying, if present, the outer layer, the CMAS mitigation layer comprising a CMAS mitigation composition consisting of cordierite, at least a portion of the environmental barrier coating being susceptible to infiltration by CMAS, the BSAS in at least one of the transition and outer layers being reactive with CMAS and the CMAS mitigation composition of the CMAS mitigation layer being effective to prevent or slow a reaction between CMAS and the BSAS; and an abradable layer applied to the separate CMAS mitigation layer.