曹卉,芮执元,冯瑞成,陈文科,冯玉玺,剡昌锋.Al含量对TiAl合金力学性能的影响[J].稀有金属材料与工程,2019,48(4):1102~1108.[Cao Hui,Rui Zhiyuan,Feng Ruicheng,Chen Wenke,Feng Yuxi,Yan Changfeng.Effects of Al content on the mechanical properties of single crystal TiAl alloy[J].Rare Metal Materials and Engineering,2019,48(4):1102~1108.]
Al含量对TiAl合金力学性能的影响
投稿时间:2017-10-31  修订日期:2017-12-18
中文关键词:  TiAl试件  Al含量  分子动力学  塑性  裂纹扩展
基金项目:
中文摘要:
      TiAl合金虽然具有很多优良性能,在航空航天和汽车工业广泛运用,但其室温脆性、断裂韧性还有待解决。本文通过改变TiAl中Al的含量,用分子动力学方法研究了Al含量对含有裂纹的单晶TiAl试件性能及裂纹扩展的影响,分析了不同Al含量下的应力-应变曲线,缺陷的演化过程。模拟结果表明:Al含量不同,材料的弹性模量和强度也不同。Al含量低于45at%时,由于层错和位错的产生以及位错反应和运动产生的空位和空位的迁移提高了试件的塑性使得试件表现出良好的塑性,而大于该含量时,试件呈明显的脆性;Al含量较低时,裂纹以塑性变形的方式扩展,Al含量较高时,裂纹以脆性方式断裂。即Al 含量会影响材料的性能;随着Al含量降低,试件的塑性增强,此外,Al含量对裂纹的扩展机制也有很大影响。
Effects of Al content on the mechanical properties of single crystal TiAl alloy
英文关键词:TiAl specimen  Al content  molecular dynamics  plasticity  crack propagation
英文摘要:
      TiAl alloy has been widely used in the aerospace and automotive industry because of its excellent properties, but the shortcomings such as brittleness and fracture toughness are still significant at room temperature, which limits its applications. The purpose of this paper is to explain the effects of Al content on the mechanical properties and to discuss the crack propagation mechanism of single crystal TiAl using molecular dynamics simulation. The stress–strain curves and evolution process of the defects were obtained under different Al contents. The results confirmed that the Al content would affect the elastic modulus and the strength of the TiAl alloy. Because of defects, such as stacking faults, dislocations and vacancies, and their migrations result in the plasticity of TiAl tended to be better when the Al content below 45at%. And the specimen implies brittleness with the Al content greater than 45at% obviously. Furthermore, the plasticity deformation dominated the main mode in the low content, while the crack fracture presented brittleness when the Al content is high. Al contents would affect the mechanical proprieties of TiAl alloy and the plasticity of TiAl would increase with decreasing Al content. In addition, the mechanism of crack propagation would vary with the change of Al content.
作者单位E-mail
曹卉 兰州理工大学 机电工程学院 1042126484@qq.com 
芮执元 兰州理工大学 机电工程学院  
冯瑞成 兰州理工大学 机电工程学院  
陈文科 兰州理工大学 机电工程学院  
冯玉玺 兰州理工大学 机电工程学院  
剡昌锋 兰州理工大学 机电工程学院  
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