Abstract

Hybrid water/argon-stabilized plasma (WSP-H) torch may be used for efficient large-scale deposition of coatings from various types of feedstocks; i.e. coarse dry powders; suspensions; and solutions. This study presents results of recent thermal cycling experiments of several novel thermal barrier coatings (TBCs) deposited by WSP-H torch on nickelbased superalloy with NiCrAlY bond-coat. Top-coats with different designs of microstructures deposited from YSZ suspension and YSZ powder were successfully prepared and tested by thermal cycling fatigue (TCF) tests. In addition to that; “Quadlayer” coating with layered top-coat consisting of three sublayers: i) yttria stabilized zirconia (YSZ) deposited from solution; ii) gadolinium zirconate (GZO) deposited from suspension; and iii) yttrium aluminum garnet (YAG) overlayer deposited from suspension was also successfully prepared; tested by TCF test and with advanced laser-rig setup exposing the TBC layer to very high temperature (>1500 °C) combined with considerable thermal gradient. Obtained results clearly show potential of WSP-H technology for novel TBC applications where; e.g.; protection of large components and/or deposition of thick coatings are desirable.

This content is only available as a PDF.