Dense Vertically Segmented Thermally Sprayed YSZ for TBC and other High Temperature Applications

摘要

The thermally sprayed YSZ coating Zircoat~(TM) is described in terms of structure and properties. The high in-plane compliance allows greater TBC layer thickness to have better thermal cycling resistance than conventional low density YSZ coatings. Thermal conductivity and sintering behavior was compared to a low density YSZ coating. Erosion testing was done at 25℃ using 50-micron angular alumina erodent at 61 and 274 m/sec. particle velocity, and at 871 ℃ at 274 m/sec. These results are compared to lower density YSZ coatings. Results for Zircoat as a blade tip coating are shown in high speed rub tests against different density YSZ seal coatings. Results for Zircoat as a seal coating show good abradabiliry if the blade tip is coated with cBN abrasives in an electroplated NiCoCrAlY matrix. employed there could be another thermal spray process capable. However, their porosity level is presently much too high to be considered in the Zircoat class. The principle of zirconia coating segmentation by the PST method is to control deposition stress to a point above the threshold for in-plane tensile fracture. By manipulating the coating stress parameters segmentation cell size can be controlled, or even eliminated by coating at low stress below the threshold.