Layered thermal barrier coatings containing lanthanide series oxides for improved resistance to CMAS degradation

摘要

A coating applied as a two layer system. The outer layer (22) is an oxide of a group IV metal selected from the group consisting of zirconium oxide, hafnium oxide and combinations thereof, which are doped with an effective amount of a lanthanum series oxide. These metal oxides doped with a lanthanum series addition comprises a high weight percentage of the outer coating (22). When the zirconium oxide is doped with an effective amount of a lanthanum series oxide, a dense reaction layer is formed at the interface of the outer layer of TBC and the CMAS. This dense reaction layer prevents CMAS infiltration below it. The second layer, or inner layer (20) underlying the outer layer (22), comprises a layer of partially stabilized zirconium oxide.