等离子喷涂ZrO2热障涂层的抗热震性能

为了进一步了解等离子喷涂ZrO2涂层的制备及失效控制措施,提高涂层的使用寿命,研究了涂层在水淬和火焰喷烧两种条件下的抗热震性能.结果表明:水淬条件下垂直裂纹主要分布在距涂层中心12mm范围内,随热震次数的增加,垂直裂纹最终进入次表层,靠近中心处裂纹扩展较快;火焰喷烧条件下垂直裂纹分布在距涂层中心10 mm范围内,随热震次数的增加,裂纹在表面层和次表层界面处发生偏转,中心处裂纹扩展较快;火焰喷烧条件下涂层的抗热震性能优于水淬下,涂层中孔隙的存在加速了两种条件下裂纹的扩展.

Thermal Shock Resistance of Plasma-Sprayed ZrO2Thermal Barrier Coatings

The thermal shock resistance of plasma-sprayed ZrO2 thermal barrier coatings under the conditions of water quenching and flame jet was studied.It was found that under the condition of water quenching,the vertical cracks were mainly generated and distributed in the zones about 12 mm within the center of the coating;the vertical cracks were developed into the subsurface with increasing cycle of thermal shock,and the cracks near to the center of the coating were propagated at a faster rate.Under the condition of flame jet,the vertical cracks were mainly generated and distributed in the zones about 10 mm within the center of the coating;the vertical cracks propagating faster near the center of the coating assumed a deflexion at the interface between the top-coating and the subsurface-coating with increasing cycle of thermal shock;and the cracks near to the center of the coating were propagated as well at a faster rate under this condition.Moreover,the plasma-sprayed ZrO2 thermal barrier coating showed better thermal shock resistance under the condition of flame jet than under that of water quenching,and the pores in coating accelerated the propagation of the cracks under two conditions.