Effect of Recast Layer Thickness of High-Carbon Alloy (EN-31) in Wire EDM Process by Varying Operating Parameters

Abstract

AbstractWire electrical discharge machining is unconventional material erosion process having wide application in manufacturing industries for machining of complex profiles and hard to machine materials. The sub-surface layer of WEDM-machined specimen is crucial because of the presence of recast layer thickness (RLT) and heat-affected zone. The present research focused on detailed analysis on recast layer thickness of WEDM-machined surface of EN-31 high-carbon alloy steel using scanning electron microscope (SEM). EN-31 alloy steel is extensively used for manufacturing of plastics mold and dies. Press tools, punches due to its exceptional physical and mechanical properties. The experimental matrix adopted for machining is as per Taguchi’s design of experiment, and the process variables considered are as follows: pulse on time, pulse off time, wire feed, gap current, wire tension, spark gap set voltage, and servo feed. From the analysis of machined surfaces using scanning electron microscopy (SCM), it is found that the recast layer thickness increases with increase in pulse on time, gap current and reduced pulse off time, spark gap set voltage. Similarly, low RLT is observed at reduced level of pulse on time, gap current and higher value of pulse off time, spark gap set voltage.KeywordsComplex profile machiningRecast layer thicknessPulse timeGap current