THERMAL BARRIER COATING HAVING HIGH PHASE STABILITY

摘要

A device (10) comprising a substrate (22) having a deposited ceramic thermalbarrier coating layer (20) characterized by a microstructure having gaps (28)where the thermal barrier coating (20) consists essentially of a pyrochlorecrystal structure having a chemical formula consisting essentially of An+2-xBm+2+xO7-y, where A is selected from the group of elements selected from La,Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and mixtures thereof; where Bis selected from the group of elements selected from Zr, Hf, Ti and mixturesthereof; n and m are the valence of A and B respectively, and for -0.5 = x =0.5, y = formula (I), and excluding the following combinations for x = 0, y =0: A = La and B = Zr; A = La and B = Hf; A = Gd and B = Hf; and A = Yb and B =Ti. The preferred pyrochlore crystal structure is Sm2Zr2O7, which is stableover the range of operating temperatures of the device (10) up to at leastabove 1400 ~C, and where the thermal barrier coating (30) can be depositedover a separate bottom fluorite thermal barrier coating.