(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
2. 中南大學(xué) 教育部有色金屬材料重點(diǎn)實(shí)驗(yàn)室，長沙 410083；
3. 中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083；
4. 中南大學(xué) 深圳研究院，深圳 518057)
摘 要: 針對高溫?zé)嵴贤繉又嘘P(guān)鍵的過渡層/熱生長層界面，通過第一性原理界面熱力學(xué)建模和密度泛函計(jì)算，考察微量鋯元素對g-Ni(Al)/α-Al2O3界面結(jié)構(gòu)、偏析、和界面結(jié)合的影響，以及在基體中對雜質(zhì)(硫)的釘扎。結(jié)果顯示：鋯具有與同族元素鉿類似的界面強(qiáng)化作用，其強(qiáng)化機(jī)理可以歸納為3種，即在基體中有效釘扎硫，以抑制硫的有害界面偏析、在界面處置換硫，以減輕偏析硫?qū)缑娴奈：σ约霸诮缑嫫鲆灾苯訌?qiáng)化界面結(jié)合，可使較弱的理想化學(xué)計(jì)量比界面的分離功提高3倍。
關(guān)鍵字: 熱障涂層；界面強(qiáng)度；微合金化；鋯；第一性原理
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials, Ministry of Education, Central South University, Changsha 410083, China;
3. National Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China;
4. Shenzhen Research Institute, Central South University, Shenzhen 518057, China）
Abstract: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-Al2O3 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.
Key words: thermal barrier coating; interface adhesion; micro-alloying; zirconium; first-principles
