Re对Ni_(3)Al屈服强度及断裂强度影响的第一原理研究  

Effect of Re on Yield Strength and Fracture Strength of Ni_(3) Al Based on First⁃Principles Study

作　　者：胡雪兰[1] 卢睿智 王智隆 王梦媛 王亚如 HU Xuelan;LU Ruizhi;WANG Zhilong;WANG Mengyuan;WANG Yaru(Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学中欧航空工程师学院,天津300300

出　　处：《南京航空航天大学学报》2021年第1期125-129,共5页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：中央高校基本业务经费(3122018Z004)资助项目。

摘　　要：为了满足航空发动机热端部件材料力学性能的不断提高,应用基于密度泛函理论的第一原理方法,研究了Re对Ni_(3)Al金属间化合物力学强度的影响。通过建立掺杂Re前后Ni_(3)Al的滑移模型和断裂模型,计算了晶胞的不稳定堆垛层错能γ_(US)和断裂能γ_(C),进而判断Re对Ni_(3)Al屈服强度和断裂强度的影响。另外根据经验判据,γ_(C)/γ_(US)值可表征材料的韧脆性。计算结果表明,Re的掺杂增大了Ni_(3)Al[112](111)和[110](111)两个滑移系下的γ_(US),使得滑移系不易开动,不易使Ni_(3)Al发生塑性变形,增大了Ni_(3)Al的屈服强度。Re增大了Ni_(3)Al在密排面处的断裂能,使得其不易在密排面发生断裂,增大了断裂强度。关于改善Ni_(3)Al的韧性,Re的掺杂对于密排面上不同滑移方向的影响具有一定的差别。此研究工作可为改善航空发动机单晶叶片的力学性能提供理论基础。In order to meet the continuous progress of the mechanical properties of aeroengine hot-end components,the effects of Re on the mechanical strength of Ni_(3)Al intermetallics are investigated by the firstprinciples calculation based on density functional theory.By establishing the slip model and fracture model of Ni_(3)Al before and after doping Re,unstable stacking fault energyγ_(US) and fracture energyγ_(C) are calculated,and then the effects of Re on the yield strength and fracture strength of Ni_(3)Al are determined.In addition,according to empirical criteria,theγ_(C)/γ_(US) value can characterize the toughness or brittleness of materials.The results show that Re augmentsγ_(US) in the two slip systems[112](111)and[110](111)of Ni_(3)Al,indicating Re makes them difficult to move.Thus Re makes Ni_(3)Al difficult to perform the plastic deformation and enhances its yield strength.Furthermore,Re augmentsγ_(C) at the close-packed surface of Ni_(3)Al,making it difficult to fracture at the surface and enhancing its fracture strength.Regarding to improving the toughness of Ni_(3)Al,Re has different effects in the different slip directions at the close-packed surface.The research can provide the theoretical basis for improving the mechanical properties of single crystal blades of aeroengines.

关 键 词：材料物理与化学 第一原理计算 NI3AL金属间化合物 合金化元素Re 力学强度 

分 类 号：V250.3[一般工业技术—材料科学与工程]