Electrochemical machining for micro holes with high aspect ratio on metal alloys using three-electrode PPS in neutral salt solution
To get micro holes with high aspect ratio on metal alloys by electrochemical machining (ECM) process, the mutual restricted problems between machining localization and efficiency are researched. By analyzing the thickening process of passive film, the mechanism of gas inhibition and dissolution promotion (GIDP) is explored. Thereby, a three-electrode pulse power supply (PPS) is designed to acidize on the workpiece/solution interface, for both better machining localization and efficiency. Micro ECM experiments, using the three-electrode PPS in neutral salt solution as electrolyte, are carried out on 304 stainless steel and 18CrNi8 alloy, in which a micro hollow electrode is used to flush electrolyte under high-pressure supply. It is found that the material removal rate (MRR) is increased by at least 80% and surface roughness R a is dropped by 40%, compared to those of two-electrode PPS. Micro array holes with diameter of about 175 μm are machined through metallic plates with thickness of 0.5 and 1.1 mm respectively. The micro array holes obtained have high consistent precision, good surface quality, and aspect ratio up to 6.5. Experimental results show the feasibility of micro ECM techniques proposed for micro hole with high aspect ratio.
KeywordsElectrochemical machining (ECM) Gas inhibition and dissolution promotion (GIDP) Three-electrode pulse power supply (PPS) Micro holes High aspect ratio Electrolyte Metal alloys
Unable to display preview. Download preview PDF.
- 6.Kock M, Kirchner V, Schuster R (2003) Electrochemical micromachining with ultrashort voltage pulses–a versatile method with lithographical precision. Electrochimica Acta 48: 3213–3219. Dio: 10.1016/S0013-4686(03)00374-8
- 7.Schuster R, Kirchner. V, Allongue P, Ertl G (2000) Electrochemical micromachining. Science 289: 98–101. dio: 10.1126/science. 289.5476.98
- 8.Ahn SH, Ryu SH, Choi DK, Chu CN (2004) Electro-chemical micro drilling using ultra short pulses. Precision Engineering 28: 129-134. dio: 10.1016/j.precisioneng.2003.07.004
- 9.ZENG WL, Wang ZL (2008) Rapidly erasing maintaining voltage pulse power source used in electrochenmical micromachining. Journal of Shanghai Jiao Tong University 42:1410-1413. doi: 1006-2467(2008)09-1410-04 (in Chinese)Google Scholar
- 14.Spieser A, Ivanov A (2015) Design of a pulse power supply unit for micro-ECM . Int J Adv Manuf Technol 78:537–547. doi: 10. 1007/s00170–014–6322-5Google Scholar
- 17.LI XH, WANG ZL, ZHAO WS (2006) Electrolytic micromachining with high frequency short pulse current. Chinese Journal of Mechanical Engineering 42: 162–167. (in Chinese)Google Scholar
- 20.Shibuya N, Ito Y, N. Natsu W (2012) Electrochemical machining of tungsten carbide alloy micro-pin with NaNO3 solution. Int J Precis Eng Manuf 13: 2075–2078. doi: 10.1007/s12541-012-0273-2
- 22.Fan ZJ, Wang TC (2004) ECM technology and research methods. Defense Industry Press, Beijing (in Chinese)Google Scholar
- 24.Kong QC, Li Y, Liu GD, Li CJ, Tong H (2015) Three-electrode pulse power supply for micro ECM. Journal of Tsinghua University (Science and Technology) 55:266–272 (in Chinese)Google Scholar