الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
A laboratory for electrochemical machining was started comprising principally of a drilling machine in assembly with auxiliaries and necessary instruments. Sodium chloride solution of 10 %strength was selected as a cheap working electrolyte for hardened steel drilling. Specimens were subjected to systematic practical trials to explore the various operating parameters governing the process and their relations.
The working conditions studied included roles of variation of gap voltage, electrolyzing current, tool-feed rate , metal removal rate and their efficiencies. Their behaviour was studied and compared with previous findings. Effects of these parameters on the quality of drilled specimens,whether withrespect to hole oversize, hole conicity and surface finish,were investigated.
Another series of test runs was performed using small additions of hydrogen peroxide (H2O2) as an oxygen supplier to the electrolysis bath. Its disadvantages, when present, were discussed and its merits were evaluated.
At the optimum gap voltage of 22v, o.2% H2O2 brought about a substantial increase in current efficiency for tool-feed rate from 55 to 78% and for metal-removal rate from 53 to 64%. In addition, there are some improvements in hole oversize, hole conicity and surface finish.