(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) 有色金屬材料教育部重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 基于第一性原理方法，研究溫度、原子化學(xué)配比、Al 活度、O活度和雜質(zhì)偏聚對內(nèi)氧化Cu/Al2O3界面的影響作用。計(jì)算得到的界面相圖及相應(yīng)能量學(xué)結(jié)果表明：界面平衡相結(jié)構(gòu)隨制備氣氛的變化而變化；富O相界面的結(jié)合強(qiáng)度最高，富Al相界面的結(jié)合強(qiáng)度其次，它們均約3倍于理想化學(xué)配比相界面的結(jié)合強(qiáng)度；雜質(zhì)S對界面的危害性明顯，對富Al相和理想配比相界面具有強(qiáng)烈的偏聚能力，且嚴(yán)重削弱界面強(qiáng)度(約可達(dá)65%)，并降低氧化鋁顆粒尺寸的穩(wěn)定性，但S不能向富O 相界面偏聚；相較于S，另一種雜質(zhì)P向富Al相和理想配比相界面的偏聚能力不強(qiáng)，偏聚后對界面的危害性也較S弱。但P能向富O相界面偏聚，使界面強(qiáng)度嚴(yán)重降低。
關(guān)鍵字: Cu/Al2O3界面；內(nèi)氧化；結(jié)合強(qiáng)度；雜質(zhì)偏聚；第一性原理
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials, Ministry of Education, Central South University, Changsha 410083, China）
Abstract:Based on the first-principles study, the effects of temperature, interfacial stoichiometry, Al activity, O activity and impurity segregation on the internally oxidized Cu/Al2O3 interface were studied. The calculated interfacial phase diagrams and corresponding energetics suggest that, the equilibrium interface structure varies with the ambient; the O-rich type interface, followed by the Al-rich type, has significantly stronger adhesion than its stoichiometric counterpart. Impurity S strongly segregates to Al-rich and stoichiometric type interfaces, degrades the adhesion (up to about 65%) and also reduces the size stability of alumina particles in Cu, while the O-rich interface is immunized from S segregation. P, as another common impurity in Cu, has a limited capability to segregate to the Al-rich and the stoichiometric interfaces, but it can segregate to the O-rich interface and reduce the adhesion seriously.
Key words: Cu/Al2O3 interface; internal oxidation; adhesion strength; impurity segregation; first principles
