A PROCEDURE FOR HIGH INTEGRITY EDM SURFACES

Certain components by nature of their material or shape definitely lend themselves to Electrical Discharge Machining (EDM) processing, and the newer techniques and equipment bring economies such that EDM is competitive in an ever larger group of conventionally machinable parts. The study reported on in this paper was initiated to determine the practical effects of both conventional machining and EDM in production, and to investigate means of producing high-integrity EDM surfurces. The investigation has shown that a smooth, essentially stress-free surface can be produced on high-strength steel after heat treatment, using calculated EDM cuts and electrochemical finishing to remove the final EDM affected layer. A method of surface characterization by electron profile has been applied to assist the study which appears to accurately compare surfaces of the types now commonly produced. References.