(1. 上海交通大學(xué) 材料科學(xué)與工程學(xué)院，上海 200240； 2. 上海市先進(jìn)高溫材料及其精密成形重點實驗室，上海 200240； 3. 上海交通大學(xué) 金屬基復(fù)合材料國家重點實驗室，上海 200240)
摘 要: 采用基于密度泛函理論的第一性原理方法，計算合金原子在Cu/γ-Fe界面不同點陣位置的置換能，確定合金元素在Cu/γ-Fe界面模型的占位。通過對晶格錯配度、界面結(jié)合能、界面能和電子結(jié)構(gòu)的計算分析合金元素對Cu/γ-Fe界面特性的影響。計算結(jié)果表明：合金元素B、Si、P、Al、Zr使界面結(jié)合能增大，增強Cu/γ-Fe界面穩(wěn)定性；B、Si、P等11種合金元素則會使界面能降低，有利于γ-Fe的時效析出形核。因此，B、Si、P、Al、Zr可以促進(jìn)γ-Fe的析出，同時形成穩(wěn)定的γ-Fe相。通過合金原子相對體積、晶格錯配度和差分電荷密度的計算，分析合金元素的作用機(jī)制。
關(guān)鍵字: Cu/γ-Fe界面；第一性原理；界面能；界面結(jié)合能
（1. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; 2. Shanghai Key Lab of Advanced High-temperature Materials and Precision Forming, Shanghai 200240, China; 3. The State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:The substitutional energies of alloying atoms at different interface sites were calculated by first-principles method based on density functional theory, which gives the most favorable sites of alloying atoms. The lattice misfits, work of adhesion, interfacial energy and electronic structure were calculated to analyze the effects of alloying elements on Cu/γ-Fe interfacial properties. The results show that alloying elements B, Si, P, Al, Zr can improve the stability of Cu/γ-Fe interface by increasing the work of adhesion, while eleven kinds of alloying elements such as B, Si, P etc. reduce the interfacial energy, which is beneficial to the nucleation of γ-Fe. Therefore, B, Si, P, Al, Zr may accelerate the precipitation and form stable γ-Fe phase. The solute volumes of alloying atoms, lattice misfits and charge density difference explain well on the working mechanisms of the alloying elements.
Key words: Cu/γ-Fe interface; first-principles; interfacial energy; work of adhesion
