Abstract
Electrode gap distance is very important in electrochemical machining, because it influences the machining accuracy and the electrode correction is founded on it. In this report equations on the gap distance were mathematically derived.
(1) The equilibrium gap distance he (cm) is derived as follows he=η·Ex/v·k/ρ where η is current efficiency, E is gap voltage (V), x is specific electrical conductance (Ω-1cm-1), v is feed rate of electrode (cm/s), k is electrochemical equivalent (g/C), ρ is density of work material (g/cm3).
(2) Considering the concentration of hydrogen gas bubbles and the temperature rise of electrolyte, the equilibrium gap distance is modified as follows h′e-he(1+0.44EρH/(1-ρH))·2(1-ρH)/(2+ρH) where h′e is modiffied equilibrium gap distance, ρH is volume concentration of hydrogen gas bubbles.
(3) From these equations the foundamental contour machined is determined. The optimum stock removal from rough machining to finish is related to the contour accuracy.
