等离子喷涂Sc_2O_3、Gd_2O_3和Y_2O_3复合稳定ZrO_2热障涂层相稳定性及导热性研究

Phase Stability and Thermal conductivity of Plasma Sprayed Scandia, Gadolinia, Yttria-stabilized Zirconia Thermal Barrier Coating

采用化学共沉淀-煅烧法制备了Sc2O3、Gd2O3和Y2O3复合稳定ZrO2陶瓷原粉,陶瓷原粉经球磨、团聚造粒和烧结处理后得到适于等离子喷涂工艺的热喷涂粉末。测试分析了Sc2O3、Gd2O3和Y2O3复合稳定ZrO2热喷涂粉末微观形貌、流动性及其等离子喷涂涂层的相稳定性及导热性。结果表明Sc2O3、Gd2O3和Y2O3复合稳定ZrO2材料及其等离子喷涂涂层具有优异的高温相稳定性,即使在1400℃热处理500小时依然呈四方相结构、无单斜相出现,涂层热导率比单一Y2O3稳定ZrO2涂层明显降低,Sc2O3、Gd2O3和Y2O3复合稳定ZrO2可以用作新型超高温热障涂层材料。

Zirconia stabilized with a combination of scandia, gadolinia and yttria （SGYZ） ceramic powder was synthesized by chemical coprecipitation and calcination processes. The powder was milled, agglomerated and sintered to be suitable for plasma spraying. The microstructure, flowability of the powder and the phase stability and the thermal conductivity of the SGYZ coatings was analysed. The results revealed that the SGYZ coating had excellent stability to retain single tetragonal t ＇ phase even after high temperature （1400 ℃ ） exposure for 500 hours and did not undergo a tetragonal-to-monoclinic phase transition upon cooling. Furthermore, the plasma sprayed SGYZ coatings have lower thermal conductivity than single yttria-stabilized zirconia coatings. SGYZ may be developed as a novel ultra-high temperature TBC material.