Pulsed Unipolar-Polarisation Plasma Electrolytic Polishing of Ni-Based Superalloys:A Proof of Conception  

作　　者：Chuanqiang Zhou Ning Qian Honghua Su Jingyuan He Wenfeng Ding Jiuhua Xu 

机构地区：[1]Jiangsu Key Laboratory of Precision and Micro‑Manufacturing Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China [2]JITRI Institute of Precision Manufacturing,Nanjing 211806,China

出　　处：《Chinese Journal of Mechanical Engineering》2024年第5期163-179,共17页中国机械工程学报（英文版）

基　　金：Supported by National Natural Science Foundation of China(Grant No.52205476);the Youth Talent Support Project of Jiangsu Provincial Association of Science and Technology(Grant No.TJ-2023-070);the Fund of Prospective Layout of Scientific Research for Nanjing University of Aeronautics and Astronautics(Grant No.1005-ILB23025-1A);the Fund of Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology(Grant No.1005-ZAA20003-14).

摘　　要：The enhanced performance of aerospace equipment drives parts development towards integration,complexity,and structural optimization.This advancement promotes metal near-net fabrication technologies like wire electrical discharge machining(WEDM)and 3D printing.However,the high initial surface roughness from WEDM or 3D printing poses significant challenges for the high-performance surface finishing required.To effectively reduce the surface roughness of the workpieces with high initial surface roughness,this paper proposes pulsed unipolar-polarisation plasma electrolytic polishing(PUP-PEP).The study examined the material removal mechanisms and surface polishing quality of PUP-PEP.This technique combines the high current density and material removal rate of the electrolytic polishing mode with the superior surface polishing quality of PEP through voltage waveform modulation.For an Inconel-718 superalloy part fabricated by WEDM,PUP-PEP reduced surface roughness from R_(a)7.39μm to R_(a)0.27μm in 6 min under optimal conditions.The roughness decreased from R_(a)7.39μm to R_(a)0.78μm in the first 3 min under pulsed unipolar-polarisation voltage,resulting in a remarkable 233%increase in efficiency compared to that with conventional PEP.Subsequently,the voltage output voltage is transformed into a constant voltage mode,and PEP is continued based on PUP-PEP to finally reduce the workpiece surface roughness value to R_(a)0.27μm.The proposed PUP-PEP technology marks the implementation of‘polishing’instead of conventional rough-finish machining processes,presenting a new approach to the surface post-processing of metal near-net fabrication technologies.

关 键 词：Pulsed unipolar-polarisation Plasma electrolytic polishing Voltage waveform SUPERALLOY Surface roughness Material removal rate 

分 类 号：TG175[金属学及工艺—金属表面处理]