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TitleElectrochemical Machining
TagsElectric Current Machining Electrical Resistivity And Conductivity Electrochemistry Diffusion
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Total Pages104
Table of Contents
                            Table of Contnents
	General Discription of ElectricalChemical Machining
	2.1. FUNDAMENTALS OF ELECTROCHEMICAL MACHINING
	2.2. Current distribution
	2.3. The “ideal” ECM process.
	2.4 Tool-electrode design
	2.5 The “Non-Ideal” ECM Process
	2.6 Mathematical Modeling of ECM sinking process
	2.7 Pulse Electrochemical Machining
	2. 8 Surface Roughness and Layer Integrity after Pulse Electrochemical Machining
	3. ECM EQUIPMENT
	4. POWER SUPPLIES FOR ECM MACHINE TOOLS
	5. CONTROL SYSTEMS OF ECM MACHINES
	6. TECHNIQUES AND PROCEDURES
	7. SAFETY IN ECM AND WASTE DISPOSAL
	References
                        
Document Text Contents
Page 1

Electrochemical Machining

Electrochemical Machining
Chapter 1 GENERAL DESCRIPTION OF ELECTROCHEMICAL MACHINING

Chapter 2 FUNDAMENTALS OF ELECTROCHEMICAL MACHINING

2.1 PRINCIPLE OF ELECTROCHEMICAL SHAPING

2.2 CURRENT DISTRIBUTION

2.3 THE "ideal" ECM PROCESS

2.4 TOOL-ELECTRODE DESIGN

2.5 THE "non-ideal" ECM PROCESS

2.6 MATHEMATICAL MODELING OF ECM SINKING PROCESS

2.7 PULSE ELECTROCHEMICAL MACHINING (PECM)

2.8 SURFACE ROUGHNESS AND LAYER INTEGRITY AFTER PECM

Chapter 3 ECM EQUIPMENT

Chapter 4 POWER SUPPLIES FOR ECM MACHINE TOOLS

Chapter 5 CONTROL SYSTEMS OF ECM MACHINES

Chapter 6 TECHNIQUES AND PROCEDURES

Chapter 7 SAFETY IN ECM AND WASTE DISPOSAL

References



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1. GENERAL DESCRIPTION OF ELECTROCHEMICAL MACHINING (ECM)



Electrochemical machining (ECM) is based on a controlled anodic electrochemical dissolution process
of the workpiece (anode) with the tool (cathode) in an electrolytic cell, during an electrolysis process
(Figure 1.1).

Fig.1.1. Principal scheme of electrochemical machining (ECM)


Electrolysis is the name given to the chemical process which occurs, for example, when an electric
current is passed between two electrodes dipped into a liquid solution. A typical example is that of two
copper wires connected to a source of direct current and immersed in a solution of copper sulfate in water
as shown in Figure 1. 2.


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Figure 2.16 Results of computer simulation of electrochemical smoothing process
with constant feed rate of the tool electrode [ http://www.meil.pw.edu.pl/~ecm/ ]

The stock q, that should be removed in order to bring down the surface irregularities
from R0 to R(t), initial gap S0=Sf (Fig 2.13), can be approximately be expressed as


(2.51)
Let us consider the plane-parallel gap with inclined electrode-tool feed. This is the

more general case where the direction of the feed is inclined α to the normal to
electrodes.
The effective feed rate of tool-electrode in direction to anode –workpiece is equal
to:


(2.52)

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Substitution of Eqn. 2.52 into Eqn. (2.39, 2.40, and 2.43) we can obtain description

of dynamic gap for this case of machining. For example, steady state gap (i. e.

equilibrium gap), which is measured in normal direction , becomes


(2.53)

The equilibrium gap Sn is increased with an increasing angle of inclination.

Obtained first by Tipton, “the cosines law” for gap size in steady state of ECM [6],

described above by Equ. 2.53, is used extensively in tool-electrode design as a first

approximation (see section 2.5).

2.3.4 Computer simulation of electrochemical shaping


Based on mathematical model of EC shaping process described by Eqns.2.30, for

given shape of tool electrode and conditions of machining, computer simulation of

evolution of workpiece profile can be carry out by using included software. Software

includes simulation of:

l The changes gap size during ECM using stationary electrodes

l Smoothing process by observation of changes of high R of step on the

workpiece, during ECM using stationary electrodes

l Evolution shape of workpiece in time during ECM with constant feed rate of

tool electrode



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References

12. Kozak J., Lubkowski K., and Peronczyk J., “Accuracy Problems of the
Pulse ECM”, Proceed. 22nd MTDR Int.Conf., Manchester, 1981, pp.353-
360.

13. Kozak, J., and Davydov, A., D., Soviet Electrochemistry, vol. 19, No.7,
1983, pp.769 – 775.

14. Kozak, J., Rajurkar, K., P., and Wei, B., Proceed. of the Symposium on
Materials issues in Machining and the Physics of Machining Processes,
Winter Ann. Meeting of the ASME, Anaheim, 1992, pp.131 – 146

15. Rajurkar K.,P., Wei, B., and Kozak, J., Annals of the CIRP Vol. 44/1, 1995,
pp.177 - 180.

16. Rajurkar, K.,P., Kozak, J., and Wei, B., Annals of the CIRP Vol. 42/1,
pp.231-234, 1993.

17. Pietrov Yu., N., et al., Fundamentals of Improvement of Accuracy of
Electrochemical Shaping. Stiinnca, Kishenev, 1977 ( in Russian)

18. Dikusar A., I., et al., Elektronnaya obrabotka materialov (Electron
Treatment of Metals), No. 2, 1978 (in Russian)

19. Saushkin B., P., Elektronnaya obrabotka materialov (Electron Treatment of
Metals), No. 2, 1975 (in Russian)

20. Siedykin F.,V., Technology and Economics Problems of ECM.
Mashinostroenije, Moscow, 1980 (in Russian)

21. Metals Handbook Ninth Edition Vol.16 ASM Int., 1989.

Notices:

Author of Chapter 1 and Chapter 2 :

J. Kozak

Assistance:

D. W. Siems

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