Production of hard and lubricating surfaces on miniature components through micro-EDM process

The study acclaims the generation of hard, wear-resistant, and lubricating layer on Ti alloy using molybdenum disulfide (MoS2) powders mixed in dielectric (deionized water) using a brass tool electrode (diameter 800 mu m) through the micro-electrical discharge process. The deposition rate, micro-hardness, recast layer, and surface roughness were studied for the surface generated through the process and correlated with the XRD, AFM, electron probe micro-analyzer, EDS analysis, and FESEM images. Results indicate that a higher voltage (60 V) and powder concentration (12 g/L) increase the material deposition rate in the form of intermetallic compounds deposited on the recast layer. The coated layer formed shows an increase in micro-hardness ranging from 426.42 to 714.25 HV, which is more when compared to the base material hardness of 417.61 HV. In addition to this, lower micro-cracks were seen at high powder concentration, voltage, and duty factor with improved surface quality. The pin-on-disc wear test of the coated samples was performed, and results indicated that the specific wear rate decreased with the increase in duty factor due to the formation of hard and wear-resistant intermetallic compounds as confirmed from the EDS and XRD plots.