纳米多孔γ-TiAl单晶力学性能的分子动力学模拟  

Molecular Dynamics Simulations of Mechanical Properties in Nanoporous γ-TiAl Single Crystal

作　　者：左迪[1] 

机构地区：[1]天水师范学院土木工程学院,甘肃天水741001

出　　处：《有色金属加工》2017年第4期20-24,共5页Nonferrous Metals Processing

基　　金：国家青年科学基金项目(51408289)

摘　　要：利用分子动力学模拟方法,对多孔γ-TiAl单晶沿[001]晶向拉伸时的力学性能进行了研究,发现温度的增加会降低多孔γ-TiAl单晶的力学性能,屈服应力与杨氏模量均随温度的增加呈现降低的趋势。在多孔γ-TiAl单晶发生屈服后,剪切位错环在孔洞表面形核,导致塑性变形的发生。随着应变的增加,形成具有密排六方结构的双原子层厚的堆垛层错。位错抽取算法计算显示多孔γ-TiAl单晶中的位错均为1/6<112>Shockley不全位错,且随着应变的增加,位错密度呈增加的趋势。Based on molecular dynamics simulation method,this paper presents the mechanical performance of the porous γ-TiAl single crystal under crystal stretching. It is found that the increase of temperature leads to the decrease of porous γ-TiAl single crystal's mechanical performance,the yield stress and youngs modulus decrease with the increase of temperature. After the yield of the porous γ-TiAl single crystal,the shear dislocation ring is formed on the surface of the hole,and then the plastic deformation is occurred. With the increase of strain,the stacking fault of the double atomic layer with the structure of six square rows is formed. The dislocation extraction algorithm( DXA) calculation shows that the dislocations are almost the 1/6< 112 > Shockley partial dislocation and the density of dislocation increases with the increasing of strain.

关 键 词：分子动力学模拟 γ-Ti Al单晶 屈服应力 位错 

分 类 号：TG146.2[一般工业技术—材料科学与工程]