Ga对B2-NiAl合金力学性能影响的理论研究  

Theoretical study on the effect of Ga on the mechanical properties of B2-NiAl alloy

作　　者：陈律[1] 李敏 刘逸众 CHEN Lü;LI Min;LIU Yi-zhong(Aviation Electromechanical Equipment Maintenance Department,Air Force Institute of Aeronautical Maintenance Technology,Changsha 410124,China;Aircraft Composite Structure Maintenance Laboratory,Hunan Aircraft Maintenance Engineering Technology Research Center,Changsha 410124,China)

机构地区：[1]空军航空维修技术学院航空机电设备维修学院,长沙410124 [2]湖南省飞机维修工程技术研究中心飞机复合材料维修研究室,长沙410124

出　　处：《沈阳航空航天大学学报》2020年第3期41-47,共7页Journal of Shenyang Aerospace University

基　　金：湖南省自然科学基金科教联合基金(项目编号:2017JJ5057)。

摘　　要：采用第一性原理赝势平面波方法,基于虚拟晶体势函数近似(VCA),研究了Ga微合金化(x <1. 0%,原子百分比,下同)时理想与缺陷B2-NiAl晶体的弹性常数C44,Cauchy压力参数(C12-C44)、弹性模量E、剪切模量G及其与体模量B0的比值G/B0随Ga合金化浓度x的影响。数据分析显示:对于无缺陷NiAl晶体,无论Ga原子取代Ni原子位还是取代Al原子位,都不利于NiAl晶体材料室温延性的改善;对于Ni空位缺陷,无论Ga原子取代NiAl晶体中的那种亚点阵位置,都能改善其合金的延性;而对于Ni反位缺陷,Ga原子取代NiAl晶体中的Al原子位比取代Ni原子位更具有优势,从而解释了实验研究中出现Ga微合金化能提高NiAl单晶室温延性的原因可能源于Ga原子与NiAl晶体中点缺陷之间的关联与协同作用。电子态密度分析显示,Ga原子能够协同NiAl晶体当中的点缺陷削弱Ni(d)-Ni(d)主要成键峰的杂化效应,降低主要成键峰的方向性。Based on the virtual crystal potential function approximation( VCA),the influences of the elastic constant C44,the Cauchy pressure parameter( C12-C44),the elastic modulus E,the shear modulus G and the ratio G/B0 of the ideal and defect B2-NiAl crystals on the alloying concentration x of Ga were studied by using the first-principle pseudopotential plane wave method. Data analysis display that:whether gallium atoms replace Ni atom site or Al atom site in perfect NiAl crystal,gallium alloying is not conducive to the improvement of room temperature ductility of NiAl crystal. For the NiAl single crystal with Ni vacancy defects,the ductility of NiAl alloy can be improved whether gallium atoms replace Ni atom site or Al atom site. For the NiAl single crystal with Ni anti-site defects,Ga also can improve the room temperature ductility of NiAl single crystal,but gallium atoms replace Al atom site be superior to Ni atoms site. The above results explain that the reason of Ga microalloying energy improving the room temperature ductility of NiAl alloy may be due to the correlation and synergy between Ga atom and the point defects in NiAl crystal. The electronic density of states show s that Ga atoms can cooperate with the point defects in B2-NiAl crystal to weaken the hybridization effect of the main bonding peaks of Ni( d)-Ni( d) and to decrease the directivity of the main bonding peaks.

关 键 词：B2-NiAl Ga合金化 VCA近似 弹性性质 延性 

分 类 号：TG146.2[一般工业技术—材料科学与工程]