摘要 |
This invention relates to thermal spray processes comprising thermally depositing a high purity yttria or ytterbia stabilized zirconia powder, said powder comprising from about 0 to about 0.15 weight percent impurity oxides, from about 0 to about 2 weight percent hafnium oxide (hafnia), from about 6 to about 25 weight percent yttrium oxide (yttria) or from about 10 to about 36 weight percent ytterbium oxide (ytterbia), and the balance zirconium oxide (zirconia), onto a substrate to produce a coating having vertical segmentation cracks, essentially through the full thickness of the coating, and having from about 5 to about 200 cracks per linear inch measured in a line parallel to the plane of the coating, and having a thickness of from about 5 to about 200 mils; and having a final surface layer comprising a dipped or solution-sprayed ceramic frit coating having a thickness up to about 5 mils; and treating said surface layer with a high temperature air heat treatment to bond and adhere the surface layer. |