Machinability of elliptical ultrasonic vibration millingγ-TiAl:Chip formation,edge breakage,and subsurface layer deformation  

作　　者：Ziwen XIA Chenwei SHAN Menghua ZHANG Wengang LIU Minchao CUI Ming LUO 

机构地区：[1]Key Laboratory of High Performance Manufacturing for Aero Engine,Ministry of Industry and Information Technology,Northwestern Polytechnical University,Xi’an 710072,China [2]Engineering Research Center of Advanced Manufacturing Technology for Aero Engine,Ministry of Education,Northwestern Polytechnical University,Xi’an 710072,China [3]State Key Laboratory of Cemented Carbide,Zhuzhou 412000,China

出　　处：《Chinese Journal of Aeronautics》2025年第3期624-644,共21页中国航空学报(英文版)

基　　金：co-supported by the Science Center for Gas Turbine Project,China(No.P2022-AB-IV-001-002)and the National Natural Science Foundation of China(No.91960203);the Fundamental Research Funds for the Central Universities(No.D5000230048);and the Innovation Capability Support Program of Shaanxi(No.2022TD-60);The authors wish to thankfully acknowledge Zhuzhou Cemented Carbide Cutting Tools Co.,Ltd.for providing cutting tools for our experiments.

摘　　要：Superior strength and high-temperature performance make γ-TiAl vital for lightweight aero-engines. However, its inherent brittleness poses machining problems. This study employed Elliptical Ultrasonic Vibration Milling (EUVM) to address these problems. Considering the influence of machining parameters on vibration patterns of EUVM, a separation time model was established to analyze the vibration evolutionary process, thereby instructing the cutting mechanism. On this basis, deep discussions regarding chip formation, cutting force, edge breakage, and subsurface layer deformation were conducted for EUVM and Conventional Milling (CM). Chip morphology showed the chip formation was rooted in the periodic brittle fracture. Local dimples proved that the thermal effect of high-speed cutting improved the plasticity of γ-TiAl. EUVM achieved a maximum 18.17% reduction in cutting force compared with CM. The force variation mechanism differed with changes in the cutting speed or the vibration amplitude, and its correlation with thermal softening, strain hardening, and vibratory cutting effects was analyzed. EUVM attained desirable edge breakage by achieving smaller fracture lengths. The fracture mechanisms of different phases were distinct, causing a surge in edge fracture size of γ-TiAl under microstructural differences. In terms of subsurface deformation, EUVM also showed strengthening effects. Noteworthy, the lamellar deformation patterns under the cutting removal state differed from the quasi-static, which was categorized by the orientation angles. Additionally, the electron backscattering diffraction provided details of the influence of microstructural difference on the orientation and the deformation of grains in the subsurface layer. The results demonstrate that EUVM is a promising machining method for γ-TiAl and guide further research and development of EUVM γ-TiAl.

关 键 词：Γ-TIAL Elliptical ultrasonic vibration millingi Chip formation Edge breakage Microstructure 

分 类 号：TG506[金属学及工艺—金属切削加工及机床]