钛－氢合金力学性质及变形过程中位错运动特性的分子动力学模拟研究

项目名称： 钛－氢合金力学性质及变形过程中位错运动特性的分子动力学模拟研究

项目编号： No.51201046

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 金属材料学科

项目作者： 韩秀丽

作者单位： 哈尔滨工业大学

项目金额： 25万元

中文摘要： 采用钛合金氢处理技术，在钛合金中加入适量氢，可使其热塑性提高，热加工性能得到明显改善。目前氢致钛合金热塑性的微观机理尚不明确，需要进一步深入系统研究。氢致钛合金热塑性效应与含氢钛合金在原子尺度上对于外加应力、温度和氢含量的响应以及氢与位错间相互作用密切相关。本项目拟采用分子动力学方法从原子尺度模拟钛-氢合金的变形行为及其形变过程中位错结构演变和位错运动，研究氢含量、加载条件、变形温度、变形速度等对钛-氢合金力学性质和位错运动特性的影响规律和作用机理，建立氢与位错相互作用模型；结合高分辨电镜等测试手段，观察不同氢含量α钛合金和β钛合金变形前后位错组态和结构，验证模拟结果。本课题研究可以从原子角度揭示氢致钛合金热塑性微观机理，阐明其物理本质，丰富钛合金氢处理理论，同时为有效控制钛合金中的氢含量，制定最佳的含氢钛合金热加工工艺参数提供理论依据，具有重要的理论意义和应用价值。

中文关键词： 钛-氢合金；分子动力学；力学性质；变形；位错运动特性

英文摘要： Thermohydrogen processing (THP), which is adding appropriate hydrogen content to titanium alloys, can improve their thermo plasticity properties and thermo workability. The current understanding of the mechanism of hydrogen-induced thermoplasticity of titanium alloys is not clear and should be further investigated. The effect of hydrogen-induced thermoplasticity is closely related to the response of titanium alloys to the applied stress, temperature and hydrogen content in the atomic scale and the interaction between hydrogen atoms and dislocation. In the present application, the deformation behavior and the structure evolution and movement of dislocations during deformation process of Ti-H alloys are simulated in atomic scale by the molecular dynamics method, and the effect of hydrogen content, loading conditions, deformation temperature, deformation rate on the mechanical properties of titanium alloy and dislocation movement characteristic is studies, the mechanism of it is also revealed, and the interaction model of hydrogen and dislocation is established; The dislocation configurations and structures in titanium alloys with different hydrogen content before and after deformation are observed by high resolution electron microscopy in order to verify the simulation results. This research work can reveal the m

英文关键词： Ti-H alloy；molecular dynamics；mechanical property；deformation；dynamics characteristics of dislocation