| Title |
Thermal Properties of the Plasma - Sprayed Gradient thermal Barrier Coatings |
| Authors |
서동수(Dong Soo Suhr); 이홍로(Hong Ro Lee) |
| Abstract |
Two layer thermal barrier coatings failed by the thermal expansion mismatches beteen metallic substrate and ZrO₂ ceramic coat. Therefore, in this study, NiCr-ZrO₂(Y₂O₃) composite coat layers were introduced between substrate and ZrO₂ceramic coat in order to increase the durability by reducing the thermal expansion mismatches and by improving the bond strength. The NiCr alloy within composite coat oxidized prior to oxidation of NiCrAlY bond coat and the specimen failed within the composite coat layer. Oxidation products in composite coat layer were NiO and Cr₂O₃. The efficiency of the thermal barrier coatings increased with temperature up to 800℃ . The temperature of the substrate decreased by about 110℃ when the surface of ZrO₂ ceramic coat was heated to 800℃. |