化学短程有序在晶界处的作用及其对Al_(0.5)CoCrFeNi合金拉伸和抗辐照性能影响的分子模拟

Molecular Simulation of Chemical Short-Range Order at Grain Boundaries and Its Effect on Tensile Property and Radiation Resistance of Al_(0.5)CoCrFeNi Alloy

多主元合金中的化学短程有序结构已被视作有效的合金强化手段,而化学短程有序也会对晶界处元素分布产生影响。为研究其对合金性能的影响,采用分子动力学方法研究了几种典型晶界处的化学短程有序对Al_(0.5)CoCrFeNi合金拉伸和抗辐照性能的影响。通过位错分析及点缺陷分析阐明了相关影响机理。结果表明,错配度越高的晶界其晶界处的元素偏聚越明显。化学短程有序能够提升双晶的拉伸性能及抗辐照能力,特别是对于含错配度较大晶界的双晶,晶界能够有效吸收辐照产生的间隙原子。

The chemical short-range ordered structure in multi-principal element alloys has been regarded as an effective strengthening method.It also can affect the distribution of elements at grain boundaries.In order to study the effect on the properties of Al_(0.5)CoCrFeNi alloy,the effects of chemical short-range order at several typical grain boundaries on the tensile property and radiation resistance of Al_(0.5)CoCrFeNi alloy were studied by molecular dynamics method.The relevant influence mechanism was explained by dislocation analysis and point defect analysis.The results show that the segregation of elements at grain boundaries is more obvious with higher mismatch degree.Chemical short-range order can improve the tensile properties and radiation resistance of bicrystals,especially for bicrystals with large mismatched grain boundaries,which can effectively absorb radiation and produce interstitial atoms.