论文部分内容阅读
利用分子动力学模拟研究Ti-Al纳米杆的单向拉伸变形过程,比较分析不同拉伸速率、拉伸温度以及Al含量对Ti-Al应力-应变关系及其塑性变形行为的影响。模拟结果显示,在纳米尺度下,Ti-Al具有较高的屈服强度,且在断裂前显示出比宏观材料更好的塑性;在塑性变形中,启动(0001)面滑移系以及{10 12}<10 11>和{10 11}<10 12>孪晶是主要的变形机制;降低变形速率、提高变形温度有助于降低Ti-Al纳米杆的屈服强度,使塑性变形更容易进行,而增加Al含量则会降低Ti-Al的塑性变形能力,使Ti-Al更早发生颈缩断裂。
The uniaxial tensile deformation process of Ti-Al nanorods was studied by molecular dynamics simulation. The effects of different tensile rates, tensile temperatures and Al contents on the stress-strain relationship and plastic deformation behavior of Ti-Al nanorods were compared. The simulation results show that Ti-Al has higher yield strength at nanoscale and shows better plasticity than macro-material before fracture. In plastic deformation, the (0001) plane slip system and {10 12 } <10 11> and {10 11} <10 12> twins are the main deformation mechanisms. Decreasing the deformation rate and increasing the deformation temperature will help reduce the yield strength of Ti-Al nanorods and make the plastic deformation easier. Increasing the Al content will reduce the plastic deformation capacity of Ti-Al and cause the neck-in fracture of Ti-Al earlier.