Experimental analysis of surface integrity in electro-discharge coating process

Abstract

Utilising electro-discharge machining, powdered metallurgical tool materials are applied to coat the surface pattern-wise. The tool undergoes a thorough blending process followed by hydraulic pellet press. Essential evaluations encompass the determination of material deposition rate, tool wear rate, surface roughness, microhardness, layer thickness and wear rate. Characterisations confirm the presence of tool constituents, provide insights into its constituent's composition and reveal the formation of tungsten carbides on the uppermost surface of the deposit. Significantly, a substantially higher deposition rate of 4.9 mg/min is achieved when a compact load of 10 tons and a peak current of 2.5A are applied. Notably, the top surface exhibits a microhardness of 330.5 HV, while the base material maintains a hardness level of 98.7 HV. The maximum thickness of the deposited layer reaches 293.68 μm under identical conditions. These hard materials serve to mitigate the specific wear rate effectively.