Abstract: A ceramic material has particular utility as a thermal insulating or thermal barrier coating on metallic substrates. The ceramic material includes gadolinia and zirconia, preferably forming gadolinia-zirconia oxide. The material may include fluorite and pyrochlore structure. This material exhibits chemical stability, thermal stability and thermal insulating properties superior to those of currently used thermal barrier ceramics, and also provides resistance to sintering and erosion comparable to currently used ceramics. A preferred material has between about 5-60 mol. % gadolinia.

Abstract: Heat treated, spray formed articles are disclosed which exhibit crack growth rates and resistance to stress rupture comparable to corresponding, forged articles. The articles are first formed by depositing molten metal droplets, e.g., of IN 718, on a substrate to form a rough article. The articles are HIP'ed and then processed by heat treating, which includes solution, stabilization and precipitation heat treatments. The resultant articles have fine average grain sizes compared to forged and conventionally heat treated material, as well as yield and tensile strengths comparable to forged material. Importantly, the articles also exhibit low crack growth rates and stress rupture resistance, e.g., comparable to forged material, and have an isotropic microstructure. The articles can be used in place of forged articles.