【摘要】 耐高温、高隔热的热障涂层能有效降低涡轮叶片金属基底工作温度,从而提高发动机的热效率与性能,被列为航空发动机的关键热防护技术。然而,在燃气热冲击、冲蚀、腐蚀等恶劣环境中服役时,热障涂层极易产生涂层裂纹、界面裂纹、变形等多种损伤,并最终以涂层剥落的形式失效。采用声发射技术实时无损检测服役环境下热障涂层裂纹萌生与演化的过程,是表征涂层失效过程、揭示其机理进而预测最终剥落的有效手段。阐述了热障涂层裂纹演化的高温声发射检测方法,并着重从损伤模式、定量评估方法及基于此的热障涂层失效机理等研究方面,介绍了热障涂层失效的声发射实时表征技术的研究进展,并对其发展趋势进行了展望。更多还原

【Abstract】 Thermal barrier coatings( TBCs),with high temperature durability and excellent heat insulation, can effectively reduce the working temperature of metal base made for turbine blade,bringing about a significant improvement in both efficiency and performance of engines. Therefore,TBCs have been continually developed as a key thermal protection technique for aero-engines. However,TBCs are likely to be subject to serious damage like coating crack,interface crack,deformation and so on under serving at the complicated environment including gas shock,erosion,corrosion,etc.,which finally will peel off and fail to function. Acoustic emission technology can real-timely detect crack’s initiation and evolution process in TBCs nondestructively,which is an effective method to supervise the failure process,discover the failure mechanism and predict the failure-time for TBCs. In this paper,research progress of the high temperature acoustic emission technology on detection of the failure for TBCs will be introduced,and the method itself,crack mode identification,quantitative damage evaluation and failure mechanisms of TBCs obtained based on the method will all be elaborated in detail.更多还原