Electrochemical discharge machining

The effects occurring at the tip of the needle are shown in Fig. 6.7. During the machining most of the needle smface is insulated by the formation of a gas stream during the electrolysis. The electrical field concentrates at the tip of the needle electrode, which supplies the electrons required for the electrochemical processes. The region surrounding the needle is locally heated by electron impact. 

The material removal process depends on the composition of the workpiece. In particular, the ion conductivity of the material and its chemical resistance are of importance. The observed material removal rates for ceramics are on average 20 times smaller than those of glasses [528]. However, the material removal rate of fused silica is significantly smaller as compared to that of soda-lime silicate or borosilicate glass. 

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HF etching (4 min, 1 mm dia., 145 um deep) C02 laser drilling Ultrasonic abrasion Electrochemical discharge machining Powder blasting... 

FIGURE 2.10 Physical set-up for electrochemical discharge machining of a glass plate [135], Reprinted with permission from the Institute of Physics Publishing. 

I. Basak Electrochemical Discharge Machining Mechanism and a Scheme for Enhancing Material Removal Capacity, PhD Thesis, Indian Institute of Technology, Kanpur (1991). 

I. Basak, A. Ghosh Mechanism of material removal in electrochemical discharge machining a theoretical model and experimental verification. Journal of Materials Processing Technology 71 (1997), p. 350. 

B. Bhattacharyya, B.N. Doloi, S.K. Sorkhel Experimental investigations into electrochemical discharge machining (ECDM) of non-conductive ceramic materials. Journal of Materials Processing Technology 95 (1999), p. 145. 

A. Ghosh Electrochemical discharge machining principle and possibilities. Sadhand 22 (1997), pp. 435-447. 

M.-S. Han, B.-K. Min, S.J. Lee Modeling gas film formation in electrochemical discharge machining process using a side-insulated electrode. Journal of Micromechanics and Microengineering 18 (2008), 045019. 

A. Kulkarni, R. Sharan, G.K. Lai An experimental study of discharge mechanism in electrochemical discharge machining. International Journal of Machine Tools and Manufacturing 42 (2002), pp. 1121-1127. 

Y.-S. Liao, W.-Y. Peng Study of hole-machining on Pyrex wafer by electrochemical discharge machining (ECDM). Materials Science Forum 505—507 (2006), p. 1207. 

B.R. Sarkar, B. Doloi, B. Bhattacharyya Parametric analysis on electrochemical discharge machining of silicon nitride ceramics. International Journal of Advanced Manufacturing Technology 28 (2006), pp. 873-881. 

Fig. 6.7. Processes occurring at the tip of the needle electrode tool during electrochemical discharge machining...

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