实验时间尺度下氢对位错形核和运动的影响：计算方法，原子模拟及实验验证

项目名称： 实验时间尺度下氢对位错形核和运动的影响：计算方法，原子模拟及实验验证

项目编号： No.51271122

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 文矛

作者单位： 上海交通大学

项目金额： 80万元

中文摘要： 氢脆是金属材料破坏的一个主要因素，而导致氢脆发生的关键之一则是氢与位错的交互作用。然而，关于氢对位错形核和运动的影响目前仍存在广泛争议。虽然计算机原子模拟作为氢脆研究的一种手段越来越受到人们的重视，但目前已有的方法仍不能在实验时间尺度上模拟氢对位错行为的影响。此外，也缺乏正确描述氢化物的交互作用势函数。有鉴于此，本项目拟构建新的不仅能描述氢在铁、镍中固溶、扩散、与缺陷的结合，又能正确描述氢化物性能的嵌入原子势函数，建立实验时间尺度下氢对位错形核和运动影响的模拟方法。在此基础上模拟研究真实实验时间尺度下氢对位错形核、运动以及对裂纹扩展的影响，并通过机械性能测试和电镜分析等实验手段验证模拟结果。可以预见，本项目的实施将克服传统分子动力学模拟在氢脆研究方面的局限性，获得氢对位错行为影响的准确、可靠的结果，促进对实验和实际工程应用中氢脆发生机理的进一步了解。

中文关键词： 氢脆机理；位错；嵌入原子势函数；计算机模拟；原子研究

英文摘要： One of the primary causes for the failure of metallic materials is hydrogen embrittlement (HE), where the interaction of hydrogen with dislocations plays an important role. However, the effects of hydrogen on dislocation nucleation and motion are still the subject of widespread controversy at present. Although atomistic simulation as an effective method in studying HE is attracting more and more attention, we are still unable to simulate the effects of hydrogen on dislocation nucleation and motion at the laboratory time scale by the currently available simulation methods. In addition, there is a lack of empirical interatomic potentials describing correctly the properties of hydride phases. In light of these, the present project is designed to develop a method that can simulate the process of dislocation nucleation and motion in the presence of hydrogen at the laboratory time scale and the new embedded-atom potentials that can correctly describe not only dissolution, diffusion, binding properties of hydrogen in the metals Fe and Ni, but also the properties of their hydride phases. On this base, we will simulate the effects of hydrogen on dislocation nucleation and motion and crack propagation at the laboratory time scale and conduct mechanical testing and TEM observations to confirm the simulation results. It can

英文关键词： mechanism of hydrogen embrittlement；dislocation；embedded-atom-method potential；computer simulation；atomistic study