微合金化元素Zr对热障涂层关键界面的强化效应及机理  

Strengthening effects and mechanisms of micro-alloying Zr on key interface in thermal barrier coating systems

作　　者：蓝国强[1,2] 江勇[1,2,3,4] 江亮[3,4] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学教育部有色金属材料重点实验室,长沙410083 [3]中南大学粉末冶金国家重点实验室,长沙410083 [4]中南大学深圳研究院,深圳518057

出　　处：《中国有色金属学报》2016年第9期1967-1975,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金面上项目(51171211);国家高技术研究开发计划资助项目(2012AA03A514);深圳市科技计划项目(JCYJ20140509142357196)~~

摘　　要：针对高温热障涂层中关键的过渡层/热生长层界面,通过第一性原理界面热力学建模和密度泛函计算,考察微量锆元素对g-Ni(Al)/α-Al_2O_3界面结构、偏析、和界面结合的影响,以及在基体中对杂质(硫)的钉扎。结果显示:锆具有与同族元素铪类似的界面强化作用,其强化机理可以归纳为3种,即在基体中有效钉扎硫,以抑制硫的有害界面偏析、在界面处置换硫,以减轻偏析硫对界面的危害以及在界面偏析以直接强化界面结合,可使较弱的理想化学计量比界面的分离功提高3倍。Bond-coat/thermally-growth-oxide interface is the key interface in high-temperature thermal barrier coating systems. The first-principle interface thermodynamics modeling combined with density functional theory calculations were performed to investigate the effects of micro-alloying Zr on the γ-Ni（Al）/α-Al_2O_3 interface structure, segregation, and adhesion, and pinning impurity（S） in the matrix. The results show that Zr plays very similar roles as Hf. The addition of Zr substantially improves the adhesion through three strengthening mechanisms： pining S in bulk Ni（Al）, displacing S from its interstitial interface sites and directly enhancing the interfacial binding. The binding strength of the weak stoichiometric interface can be enhanced by up to a factor of 3.

关 键 词：热障涂层 界面强度 微合金化 锆 第一性原理 

分 类 号：TG132.32[一般工业技术—材料科学与工程]