不同厚度及硬度的AT系列涂层尖端受载下损伤行为研究  

Study on damage behavior of supersonic plasma sprayed Al_2O_3 coating with different thickness and hardness on indentation loading

作　　者：项登峰[1] 姜祎 

机构地区：[1]中国船级社舟山办事处,浙江舟山316000 [2]中国科学院过程工程研究所多相复杂系统国家重点实验室,北京100190

出　　处：《焊接技术》2018年第2期6-13,共8页Welding Technology

基　　金：国家自然科学基金项目(51671180)

摘　　要：结合声发射技术和表面压入法研制了再制造零件涂层结合强度检测仪,为了考察检测仪的准确性,采用超音速等离子弧喷涂技术制备了不同厚度与硬度的AT系列涂层,在涂层表面进行了尖端加载试验,采用SEM观测了涂层尖端受载作用下的损伤行为,提取并分析了压入过程中压入载荷的分布特性以及声发射信号规律。结果表明,厚涂层明显减小涂层界面处的剪应力,不改变涂层内部最大剪应力,当最大剪应力优先达到层间损伤临界值,涂层内部贯穿性裂纹损伤就会优先发生,反之损伤裂纹将在界面萌生。不同硬度的涂层,其涂层韧性、层间结合状态和界面结合状态是影响涂层损伤行为的关键性因素。当涂层体系产生损伤失效时,载荷曲线给出了较为明显的突变提示;声发射信号能够准确地反映出涂层体系在压入过程中的损伤行为。A remanufacturing part coating strength detector was developed combined with acoustic emission technology and surface pressure method.In order to investigate the accuracy of the detector,the Al_2O_3 coating with different thickness and hardness was prepared by supersonic plasma spraying technology.With observing the damage behavior of the coating on indentation loading by SEM,the distribution characteristics of the press load and the law of the acoustic emission signal were extracted and analyzed during the loading process.The results showed that the thick coating significantly reduced the shear stress at the interface of the coating and didn′ t change the maximum shear stress inside the coating.When the maximum shear stress preferentially reached the critical value of the interlayer damage,the penetration of cracks within the coating would occur preferentially.In contrast,the damage would crack at the interface initiation.For the coating with different hardness,the coating toughness,the interlayer bonding state and the interface bonding state were the key factors that affect the damage behavior of the coating.When the coating system failed to produce damage,the load curve gave a more obvious mutation prompt,the acoustic emission signal could accurately reflect the damage behavior of the coating system during the pressing process.

关 键 词：表面压入法 声发射技术 AT系列涂层 尖端受载 

分 类 号：TG174.4[金属学及工艺—金属表面处理]