摘要
为了研究微观尺度下裂纹相对位置对3%铌含量的单晶γ-TiAl合金裂纹扩展过程的影响,运用分子动力学方法,建立γ-TiAl合金的晶体结构模型,模拟边界裂纹和中心裂纹扩展的过程,得到了裂纹扩展的轨迹图和能量演变图,分析了裂纹位置对3%铌含量的单晶γ-TiAl合金能量和应力-应变关系的影响,进而揭示了裂纹位置对裂纹扩展的影响。研究结果表明:中心裂纹的γ-TiAl合金在其拉伸初始阶段,受力并不集中,随后由于原子键的断裂形成了孔洞,孔洞部位抑制裂纹的扩展,因此裂纹要继续扩展需要克服更大的阻力。裂纹在中心位置和边界位置对γ-TiAl合金产生的力学影响不同,边界裂纹对材料产生断裂的危害性更大。
By the molecular dynamics method,influence of crack locations on the crack propagation is studied in atomic scale level.The atomic trajectory figures and energy evolution figures have been obtained by the simulation of a center crack and a boundary crack on a crystal structure model of theγ-TiAl alloy.The analysis of influence that varied location has on energy and stress-strain ofγ-TiAl alloy containing 3% Nb indicates that no stress concentration was found in the single crystalγ-TiAl with a center crack on the first stage of tensing;then holds are generated due to breach of atomic bonds,which will restrain the crack propagation,as a result crack propagating needs to overcome more obstruction.The boundary cracks rather than the center cracks will contribute more to the break ofγ-TiAl alloy containing 3% Nb.
作者
芮执元
杨利
孙杰锋
剡昌锋
RUI Zhiyuan1,2, YANG Li1,2, SUN Jiefeng3 , YAN Changfeng1,2(1. School of Mechanical and Electrical Engineering, Lanzhou University of Technology, Lanzhou 730050, China; 2. Lanzhou University of Technology digital manufacturing technology and application of Key Laboratory of the China＇s Ministry of Education, China; 3. School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, Chin)
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2018年第2期311-315,262,共6页
Journal of Materials Science and Engineering
基金
国家自然科学基金资助项目(51065014)
甘肃省自然科学基金资助项目(148RJZA008)
甘肃省高等学校科研资助项目(2014A-033)
