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 electrica...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.展开更多
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)+1 种基金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).
文摘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.
