【摘要】 采用原子镶嵌势函数(EAM)模拟Ni针尖(约1.5nm)/Au基体纳米压痕过程.研究结果表明,当Ni针尖与Au基体间距离达到一定值时(约0.23nm),机械的不稳定性使得针尖与基体间发生跳跃接触,产生纳米压痕和黏附现象(Au原子包裹在Ni针尖周围).当压头离开基体表面,Ni针尖被拔起,随后在针尖与基体间形成连续的由Au组成的细颈.同时计算得到整个系统在针尖接近基体、跳跃接触、压痕、黏附、形成缩颈和一系列分离过程中的势能变化.更多还原

【Abstract】 The nanoindentation during indenting Au substrate with Ni tip (about 1.5 nm) has been studied by using embedded atom method (EMA) in molecular dynamics simulation (MD) simulitions. The results showed that at certain tip-substrate distances (about 0.23 nm), mechanical instability caused the tip and the substrate surface to jump-to-contact, which in turn led to nanoindentation, adhesion or gold atom wrapping around Ni tip. The Ni tip was pulled when the indenter left the substrate surface, then a connective neck mainly composed of Au between the tip and the substrate formed. The potential energy of the system for a complete cycle of the tip approach, jump-to-contact, indentation, adhension and sequent separation was obtained.更多还原