Sintering Behaviour of Thermal Barrier Coatings (TBCs)
Takahiro Hamada, Tsuneji Kameda, Yutaka Ishiwata
Power and Industrial Systems Research and Development Center, Toshiba Corporation
Abstract
Thermal barrier coatings (TBCs) have been widely applied to the hot section parts of recent developed gas turbines. According to the demand for increasing the operating gas temperature, the development of high reliable thermal barrier coating material is thought to be very important. The objective of this study is to investigate the sintering behaviour of some atmospheric plasma sprayed zirconia base TBCs at 1373K to 1773K. In this study, ZrO2-8wt%Y2O3,(three types of powders) ZrO2-20wt%Y2O3, ZrO2-24wt%MgO and ZrO2-25wt%CeO2-2.5wt%Y2O3 were evaluated by heat treatment tests As a result of this test, ZrO2-8wt%Y2O3 (HOSP type) and ZrO2-25wt%CeO2-8wt%Y2O3 ceramic samples showed a good sintering resistant behaviour up to 1573K. It was also recognized that to reduce the impurities level and to optimize the stabilized materials of raw powders were effective to improve the sintering resistant property. Above 1573K, they showed a volume expansion because of the phase transformation. To qualify the quantity of stabilized elements for controlling the phase transformation was thought to be required over 1573K.
keywords:TBCs; Thermal Barrier; CeO wt; ceramic samples; raw powders; sintering resistant property
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