重复纳米切削对γ-TiAl合金表面质量及亚表面损伤的影响  

Effect of Repeated Nanocutting on Surface Quality and Subsurface Damage of γ-TiAl Alloy

作　　者：刘洋[1,2] 冯瑞成 姚鹏[1,2] 李海燕 曹卉[1,2] 雷春丽[1,2] 李建华[1,2] Liu Yang;Feng Ruicheng;Yao Peng;Li Haiyan;Cao Hui;Lei Chunli;Li Jianhua(School of Mechanical and Electronical Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Key Laboratory of Digital Manufacturing Technology and Application,Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学机电工程学院,甘肃兰州730050 [2]兰州理工大学数字制造技术与应用省部共建教育部重点实验室,甘肃兰州730050

出　　处：《稀有金属材料与工程》2023年第10期3507-3514,共8页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52065036);甘肃省自然科学基金(20JR5RA448);兰州理工大学红柳一流学科建设项目。

摘　　要：本研究运用分子动力学方法对单晶γ-TiAl合金重复纳米切削过程进行了模拟,研究了重复纳米切削过程中的切削力和微观缺陷演化,分析了已加工表面的粗糙度和残余应力,讨论了重复纳米切削和单次切削之间的差异。结果表明:重复纳米切削伴随着位错的形成和湮灭,第2次切削过程中的位错线长度波动小于第1次切削,切削状态更稳定;加工初始阶段的切削力迅速增大,随后切削力进入稳定加工阶段,同时发现,第2次切削的切削力小于第1次切削;二次切削后,残余应力分布更加均匀,且刀具的二次挤压作用使得加工表面层残余压应力增大;两次切削加工可以提高表面质量和降低亚表面损伤,而残余压应力的增大及加工所需能量的增加降低了已加工表面的可塑性,使得第3次切削加工对表面和亚表面没有明显改善。In this paper,the repeated nanocutting process of single crystal γ-TiAl alloy was simulated by molecular dynamics method.The evolution of cutting force and microstructure defects in the repeated nanocutting process was studied.The roughness and residual stress of the machined surface were analyzed,and the difference between the repeated nanocutting and the single cutting was discussed.The results show that the repeated nano-cutting process is accompanied by the formation and annihilation of dislocations,and the fluctuation of dislocation line length in the second cutting process is less than that in the first cutting process,and the cutting state is more stable.The cutting force increases rapidly in the initial stage of machining,and then the cutting force enters the stable machining stage.At the same time,it is found that the cutting force of the second cutting is less than that of the first cutting.After the second cutting,the residual stress distribution is more uniform and the residual compressive stress of the machined surface increases due to the twice extrusion of the tool.Secondary machining can improve surface quality and reduce subsurface damage,while the increase in residual compressive stress and energy required for machining reduces the plasticity of the machined surface,so that the third machining has no obvious improvement in surface and subsurface quality.

关 键 词：重复切削 Γ-TIAL合金 亚表面损伤 分子动力学 位错 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG111[金属学及工艺—金属材料] TH161[金属学及工艺—金属学]