(南昌航空大學(xué) 航空制造工程學(xué)院，南昌 330063)
摘 要: 采用分子動力學(xué)方法研究Al2Cu的拉伸變形行為。建立Al2Cu分子動力學(xué)模擬模型，采用嵌入原子法模擬Al2Cu模型在常溫、恒定工程應(yīng)變速率的拉伸環(huán)境下對Al2Cu力學(xué)性能的影響，探討溫度和應(yīng)變率對體系拉伸變形行為的影響。結(jié)果表明：發(fā)現(xiàn)Al2Cu非常脆，應(yīng)變ε=0.086時應(yīng)力達到峰值6.4 GPa，在拉伸初期不易產(chǎn)生位錯，從而彈性變形階段較長。Al2Cu對溫度十分敏感，溫度上升使Al2Cu的原子動能成倍增加，導(dǎo)致塑性變強但抗拉強度明顯下降；Al2Cu在應(yīng)變率為 為0.005~0.006 ps-1之間存在一個值，當Al2Cu的應(yīng)變率超過這個值時，一些拉伸產(chǎn)生的空位來不及發(fā)生大幅移位，只能聚集在發(fā)射處附近，使體系內(nèi)各處均出現(xiàn)大量孔洞。
關(guān)鍵字: Al2Cu；拉伸；分子動力學(xué)模擬；溫度；應(yīng)變率
（School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China）
Abstract:The tension deformation behavior of Al2Cu was studied by molecular dynamics method. The molecular dynamics simulation model of Al2Cu was established, and the influence of Al2Cu model on mechanical properties of Al2Cu under constant engineering strain rate tension at constant temperature was simulated by using the embedded atom method. The influences of temperature and strain rate on the tension deformation were discussed. The results show that Al2Cu is very brittle under that condition, when the strain is 0.086, the stress reaches the peak value of 6.4 GPa, and it is difficult to produce dislocations at the initial stage of tension, thus the elastic deformation stage is relatively long. Al2Cu is very sensitive to temperature. The kinetic energy of Al2Cu increases exponentially with the temperature rising, resulting in a stronger plasticity, but the tensile strength decreases obviously. The analysis also reveals a value between the strain rate of 0.005 to 0.006 ps-1, when the tensile strain rate of Al2Cu exceeds this value, some of the vacancies produced by stretching are too late to take place in the system, can only gather near the launch site, which leads to the formation of voids in the system.
Key words: Al2Cu; tension; molecular dynamics simulation; temperature; strain rate
