超音速等离子喷涂氧化锆热障涂层抗热冲击性能研究及评价  

Research and Evaluation of Thermal Shock Resistance of Zirconia Thermal Barrier Coatings Sprayed by Supersonic Plasma Spraying

作　　者：崔静[1] 郭玉珠 庞铭 杨广峰[1] CUI Jing;GUO Yuzhu;PANG Ming;YANG Guangfeng(School of Airport,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学机场学院,天津300300

出　　处：《热加工工艺》2021年第14期82-87,共6页Hot Working Technology

基　　金：国家自然科学基金项目(U1633111);中国民航大学蓝天青年学者培养经费项目(2011QD21X);中国民航大学科研启动基金项目(09QD05X)。

摘　　要：采用超音速等离子喷涂技术制备了氧化锆陶瓷涂层,进行了不同冷却介质(空冷/水冷)的循环热冲击试验,以试验循环次数来评价涂层抗热冲击性能,并利用SEM观察涂层表面及断口形貌,分析材料的抗热冲击机制。结果表明,空冷和水冷形式下的热冲击造成涂层断裂模式为脆性穿晶断裂,且断口形貌均呈"河流状"。造成涂层失效的原因是大温度梯度和涂层-基材热物性差异产生的应力,而应力导致了微裂纹产生最终失效。由于涂层材料与制备工艺的原因,涂层中存在的硬质颗粒使热冲击产生的微裂纹扩展路径发生偏转,提高了涂层断裂能,使得涂层抗热冲击性能提高。试验结果表明,氧化锆单层涂层空冷条件下的抗热冲击性能优于水冷条件,但整体抗热冲击性能偏低,有待进一步改善。Zirconia ceramic coating was prepared by supersonic plasma spraying.The cyclic thermal shock tests of different cooling media(air cooling/water cooling)were carried out to evaluate the thermal shock resistance of the coating according to the number of cycles.The surface and fracture morphology of the coating were observed by SEM,and the thermal shock resistance mechanism of the coating was analyzed.The results show that,the fracture mode of the coating is brittle transgranular fracture caused by thermal shock in air-cooled and water-cooled form,and the fracture morphology is"fluidic".The failure of the coating is induced by the stress caused by the large temperature gradient and the difference of thermal properties between the coating and the substrate,and the stress leads to the final failure of the microcrack.Due to the reason of coating material and preparation process,the hard particles in the coating deflect the microcrack propagation path caused by thermal shock,and improve the fracture energy of the coating,so that the thermal shock resistance of the coating is improved.The experimental results show that,the thermal shock resistance of zirconia monolayer coating under air cooling condition is better than that of under water cooling,but the overall thermal shock resistance of zirconia monolayer coating is low and needs to be further improved.

关 键 词：超音速等离子喷涂 氧化锆 热冲击 断口形貌 裂纹 

分 类 号：TG174.442.1[金属学及工艺—金属表面处理]