High-temperature cyclic oxidation of Pt-rich γ-γ' bond-coatings. Part Ⅱ: Effect of Pt and Al on TBC system lifetime

摘要

Three kinds of Pt-rich gamma-gamma' bond-coating were processed with different contents in Pt and Al. The cyclic oxidation tests performed at 1100 degrees C on TBC systems showed the superiority of the Pt-rich gamma-gamma' coatings when compared with the beta-(Ni,Pt)Al reference system. TBCs with a Pt-only bond-coating provided the highest performance. Whatever the bond-coating, the failure occurred at the TGO/bond-coating interface which appeared to be the weak point of these gamma-gamma' bond-coating based systems. Al addition during bond-coating fabrication did not improve the durability. A decrease of 2 pm of electroplated Pt thickness led to a higher performance than the reference systems.