Parametric Study of Electric Discharge Coating using Powder Metallurgical Green Compact Electrodes

Abstract

This paper describes the influence of powder metallurgical (P/M) electrodes on the surface of mild steel in electric discharge machining. An attempt has been made to deposit a uniform layer of tungsten and its carbide over the mild steel substrate using P/M green compact tools by electric discharge coating process. In this experimental work, W and Cu powders of 325 mesh size have been selected as electrode material and mild steel as workpiece material. A detailed investigation of process parameters, such as composition, compaction load, current, on-time, and off-time, which influence the material transfer rate (MTR), tool wear rate, roughness, and layer thickness, has been performed. Highest MTR of 281 mg/min and LT of 1262.99 µm have been achieved successfully. The hardness of deposited layer has been measured which proves that the deposited layer is 5–6 times harder than the substrate material.

Keywords:

• Electric
• Erosion
• Discharge
• Metallurgy
• Powder
• Surface coatings
• Transfer

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lmmp.