粘结层中Co与Ni元素含量对热障涂层组织及寿命的影响  

Effect of Co and Ni contents in MCrAlY bondcoats on microstructure and lifetime of APS TBC systems

作　　者：季强[1] 宋鹏[1] 王逸群[1] 廖红星[1] 陆建生[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,昆明650093

出　　处：《功能材料》2016年第4期74-78,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51401097);高等学校博士学科点专项科研基金资助项目(20125314110002);云南省应用基础研究计划资助项目(2013FB016)

摘　　要：高温服役过程中热障涂层的MCrAlY粘结层形成致密的氧化铝层,从而提高了涂层和基体的抗氧化性能。利用等离子喷涂制备的热障涂层,其粘结层中的Co与Ni的含量和界面微观结构是影响氧化的重要因素。通过在Ni基高温合金基体上利用低压等离子喷涂(LPPS)分别制备粘结层为CoNiCrAlY和NiCoCrAlY的热障涂层进行高温循环氧化实验,比较研究了这两种热障涂层在1 050℃下的循环氧化寿命和失效特征。研究表明粘结层表面形貌对氧化物的生长具有重要影响,其中CoNiCrAlY粘结层更易在TGO层中形成尖晶石氧化物,最终无法形成连续的Al_2O_3层,导致涂层失效,而NiCoCrAlY粘结层表现出不同的失效方式。同时,粘结层和基体中Ni、Co等元素在氧化过程中存在强烈的互扩散,Co与Ni含量对两种涂层BC/基体界面处宏观空洞的生长产生了不同影响。The dense alumina layer was generated on the surface of the MCrAlY bondcoats within thermal barrier coatings(TBCs)at high temperature service process,which could improve the oxidation resistance of the coating and superalloy.The Co and Ni concentrations and interface micro-structure of the bondcoats were the important factors to affect the oxidation properties for the TBCs prepared by APS.In this paper,the high-temperature cycle oxidation experiment of TBCs specimens with CoNiCrAlY and NiCoCrAlY bondcoats was carried out at 1 050 ℃.The TBCs oxidation lifetime and failure characteristics were carefully studied.The results indicate that the spinels are easily formed within thermally growth oxide(TGO)for CoNiCrAlY bondcoat,which would cause TBC spallation due to a discontinuous Al_2O_3 layer formation.In addition,the NiCoCrAlY bondcoat shows a different failure modes.Meanwhile,the strongly inter-diffusion phenomenon of Ni and Co within the bondcoat and Ni-base alloy matrix was observed during oxidation.The content of Co and Ni show different influence on generation of macroscopic pores at the interface between bondcoats and the matrix.

关 键 词：热障涂层 CONICRALY NICOCRALY 热循环 扩散 寿命 

分 类 号：TG172.82[金属学及工艺—金属表面处理]