Sulzer Metco (us) Inc.

Oerlikon Metco (us) Inc.

Matthew Gold

Liangde Xie

Mitchell R Dorfman

Richard Karl Schmid

Jacobus Cornelis Doesburg

Jacobus C Doesburg

A high purity yttria or ytterbia stabilized zirconia powder wherein a purity of the zirconia is at least 99.5 weight percent purity and with a maximum amount of specified oxide impurities.

Ceramic material for high temperature service

Thermal barrier coating made from a thermally sprayable powder that includes yttria stabilized zirconia and hafnia, from 6 to 9 weight percent yttria, and total impurities less than or equal to about 0.1 weight percent. The thermal barrier coating has from about 5 to 250 vertical macro cracks per 25.4 mm length measured along a coating surface and the macro cracks are oriented perpendicular to a surface of a substrate containing said coating.

The invention is directed to a material and method for obtaining a ceramic abradable system for high temperature applications. High purity partially stabilized zirconia and/or hafnia base material has higher sintering resistance compared to conventional 6-9 weight percent yttria stabilized zirconia systems. The benefits of these systems are higher service lifetime and low thermal conductivity to achieve high operating temperatures. System includes a superalloy substrate, oxidation resistant bond coat and a thick ceramic abradable top coat. Total coating thickness is about 0.5-5 mm. In some applications an intermediate layer of high purity partially stabilized zirconia or a partially stabilized YSZ/MCrAlY cermet is applied over the oxidation resistant bond coat. In other applications an abradable system is applied on top of a grid. Additional benefits should be reduced blade wear at high operating conditions.

High purity ceramic abradable coatings

The invention is directed to high purity zirconia-based and/or hafnia-based materials and coatings for high temperature cycling applications. Thermal barrier coatings made from the invention high purity material was found to have significantly improved sintering resistance relative to coatings made from current materials of lower purity. The invention materials are high purity zirconia and/or hafnia partially or fully stabilized by one or any combinations of the following stabilizers: yttria, ytterbia, scandia, lanthanide oxide and actinide oxide. Limits for impurity oxide, oxides other than the intended ingredients, that lead to significantly improved sintering resistance were discovered. High purity coating structures suitable for high temperature cycling applications and for application onto a substrate were provided. In one structure, the coating comprises a ceramic matrix, porosity and micro cracks. In another structure, the coating comprises a ceramic matrix, porosity, macro cracks and micro cracks. In another structure, the coating comprises ceramic columns and gaps between the columns. In another structure, the coating comprises ceramic columns, gaps between the columns and nodules distributing randomly in the gaps and columns.

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Farmingdale, NY, United States of America

Matthew Gold