High sintering resistance of a novel thermal barrier coating

Sintering resistance of a novel thermal barrier coating NdxZr1-xOy with Z dissolved in, where 0<0.5, 1.75<2 and Z is an oxide of a metal selected from Y, Mg, Ca, Hf and mixtures thereof, was studied. The coatings of NdxZr1-xOy and typical 7YSZ were deposited by electron beam physical vapor deposition (EB-PVD) and air plasma spray (APS). The samples with the coating system of EB-PVD NdxZr1-xOy or 7YSZ overlaid onto a MCrAlY bond coat were cyclically sintered at 1107 degrees C for 706 hours. The freestanding coatings of EB-PVD NdxZr1-xOy and 7YSZ were isothermally sintered at 1371 degrees C for 500 hours. The microstructure of EB-PVD NdxZr1-xOy before and after the sintering was evaluated and compared with EB-PVD 7YSZ. The sintering resistance of freestanding APS NdxZr1-xOy coating was also investigated after isothermal sintering at 1200 degrees C for 50 and 100 hours. The results demonstrated that the new coatings of NdxZr1-xOy applied with both EB-PVD and APS have higher sintering resistance than EB-PVD and APS 7YSZ, respectively. (C) 2010 Elsevier B.V. All rights reserved.