Precision and high surface integrity machining of thick rule structures in aerospace difficult-to-cut materials has become a common concern and an urgent problem in the manufacturing field. Pulse Wire ElectroChemical Machining (PWECM) has principal advantages in applications requiring high surface integrity. This paper discusses the effects of workpiece thickness on PWECM using the circuit model. Experimental results show that the electrolyte resistance, the inter-electrode voltage, and machined slit width were reduced with the increase of workpiece thickness. While the time constant of electric double layer in PWECM increases, the charging voltage including the effective machining time decreases. When the pulse frequency is greater than 20 kHz, the maximum electrode feedrate rapidly decreases with the increase of the frequency. When the pulse frequency is lower than 20 kHz, the difference of the maximum machining rate becomes smaller. Finally, a fir-tree-like turbine-disk tenon/mortise structure of 20 mm in thickness is successfully fabricated at the pulse frequency of 20 kHz and the electrode feed rate of 4 μm/s, and the surface roughness Ra was about 0.449 4 μm. The surface quality and machining efficiency at 20 kHz is significantly superior to that at 100 kHz.
CHEN Mi
,
FANG Xiaolong
,
ZHU Di
. Experimental research on pulse current wire electrochemical machining of thick structures[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2019
, 40(8)
: 422781
-422781
.
DOI: 10.7527/S1000-6893.2018.22781
[1] 徐岩, 张川. 拉刀设计对航空发动机涡轮盘榫槽型面的影响[J]. 航空制造技术, 2010(15):50-52. XU Y, ZHANG C. Influence of broach design on aeroengine turbine disk fir tree groove[J]. Aeronautical Manufacturing Technology, 2010(15):50-52(in Chinese).
[2] 姜雪梅, 赵鹏飞. 航空发动机关键转动部件加工技术[J]. 航空制造技术, 2014(7):44-48. JIANG X M, ZHAO P F. Machining technique of aeroengine critical rotating component[J].Aeronautical Manufacturing Technology, 2014(7):195-196(in Chinese).
[3] 邓朝晖, 万林林,张荣辉. 难加工材料高效精密磨削技术研究进展[J]. 中国机械工程, 2018, 19(24):3018-3023. DENG C H, WAN L L, ZHANG R H. Research progresses of high efficiency and precision grinding for hard to machine materials[J]. China Mechanical Engineering, 2018, 19(24):3018-3023(in Chinese).
[4] 孟漪. 高效精密枞树型轮槽铣刀设计制备准则及其试验研究[D]. 上海:上海交通大学, 2011. MENG Q. The design and manufacturing principle and the experiment study on high efficiency and precise fire tree milling cutter[D].Shanghai:Shanghai Jiao Tong University, 2011(in Chinese).
[5] RAJURKAR K P, SUNDARAM M M, MALSHE A P. Review of electrochemical and electrodischarge machining[J]. Procedia CIRP, 2013(6):13-26.
[6] ZHU D, WANG K, QU N S. Microwire electrochemical cutting by using in situ fabricated wire electrode[J]. CIRP Annals-Manufacturing Technology, 2007, 56(1):241-244.
[7] 王少华, 朱荻. 微尺度线电极电解加工[J]. 航空学报, 2009, 30(9):1788-1794. WANG S H, ZHU D. Micro wire electrode electrochemical nachining[J]. Acta Aeronautica et Astronautica Sinica, 2009, 30(9):1788-1794(in Chinese).
[8] 于洽, 朱荻,曾永彬,等. 微幅往复走丝微细电解线切割试验研究[J]. 航空学报, 2012, 33(5):920-927. YU Q, ZHU D, ZENG Y B, et al. Wire electrode micro-electrochemical machining with tool micro-amplitude reciprocating motion[J]. Acta Aeronautica et Astronautica Sinica, 2012, 33(5):920-927(in Chinese).
[9] ZENG Y B, YU Q, WANG S H, et al. Enhancement of mass transport in micro wire electrochemical machining[J]. CIRP Annals-Manufacturing Technology, 2012, 61(1):195-198.
[10] BÉJAR M A, ETEROVICH F. Wire-electrochemical cutting with a NaNO3 electrolyte[J]. Journal of Materials Processing Technology, 1995, 55(3-4):417-420.
[11] SHARMA V, JAIN V K, RAMKUMAR J. Experimental analysis of wire electrochemical machining process[C]//Proceedings of 6th International & 27th All India Manufacturing Technology, Design and Research Conference, 2016:472-475.
[12] KLOCKE F, HERRIG T, ZEIS M, et al. Modeling and simulation of the fluid flow in wire electrochemical machining with rotating tool (wire ECM)[C]//American Institute of Physics Conference Series, 2017:050014.
[13] KLOCKE F, HERRIG T, ZEIS M, et al. Experimental investigations of cutting rates and surface integrity in wire electrochemical machining with rotating electrode[J]. Procedia CIRP, 2018(68):725-730.
[14] QU N S, FANG X L, LI W, et al. Wire electrochemical machining with axial electrolyte flushing for titanium alloy[J]. Chinese Journal of Aeronautics, 2013, 26(1):224-229.
[15] 姚羊洋, 房晓龙,曾永彬,等. 轴向冲液电解线切割50CrVA试验研究[J]. 电加工与模具, 2017(1):60-64. YAO Y Y, FANG X L, ZENG Y B, et al. Experimentalstudy on wire electrochemical machining of 50CrVA with axial electrolyte flusing[J]. Electromachining & Mould, 2017(1):60-64(in Chinese).
[16] 张海, 曾永彬,于洽,等. 环形丝单向运丝电解线切割加工技术试验研究[J]. 中国机械工程, 2014, 25(2):223-225. ZHANG H, ZENG Y B, YU Q, et al. Experimental research on ring wire WECM with wire travelling in one direction[J]. China Mechanical Engineering, 2014, 25(2):223-225(in Chinese).
[17] QU N S, JI H J, ZENG Y B. Wire electrochemical machining using reciprocated traveling wire[J]. The International Journal of Advanced Manufacturing Technology, 2014, 72(5-8):677-683.
[18] FANG X L, ZOU X H, CHEN M, et al. Study on wire electrochemical machining assisted with large-amplitude vibrations of ribbed wire electrodes[J]. CIRP Annals-Manufacturing Technology, 2017, 66(1):205-208.
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