(上海交通大学 材料科学与工程学院,上海 200240)
摘 要: 采用晶格动力学有限元法研究α-Ti晶体单向拉伸和压缩过程中弹-塑性转变和失稳的均匀形核机制。模拟结果表明:在单向加载过程中,α-Ti理想晶格的动力学失稳特征与晶体取向和变形方式有关,并且初始塑性存在显著的各向异性和拉伸-压缩不对称性;晶体变形过程中的晶格失稳产物既有晶格畸变和位错,也观察到相变和变形孪生。
关键字: 钛;弹塑性变形;多尺度模拟;分子动力学;拉伸;压缩
(School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
Abstract:Uniaxial tension and compression of α-Ti crystal were simulated by lattice dynamics finite element method (LDFEM) to investigate the elastic-plastic transition and homogeneous nucleation mechanism of lattice disability in α-Ti. The simulation results show that lattice dynamics instability of α-Ti single crystal is associated with crystallographic and deformation model under uniaxial loading, indicating strong anisotropic incipient plasticity and tension-compression asymmetry. The predicted products of lattice disability include not only lattice distortion and dislocation but also phase transformation and deformation twining in crystal deformation process.
Key words: titanium; elastoplastic deformation; multiscale modeling; molecular dynamics; tension; compression