Preparation of MoS 2 +Cu coating through the EDC process and its analysis

Abstract

A solid-lubricant coating of molybdenum disulphide (MoS₂) and copper (Cu) powder has been prepared on the mild steel substrate using electrical discharge coating (EDC) technique. The effect of machining parameters (peak current, duty factor, and powder mixing ratio) on surface integrity and tribological characteristics of the coated surface has been investigated. XRD result indicates the formation of different compounds such as Mo, Cu, MoS₂, and FeS on the coated surface during the EDC process. The maximum coating thickness of 0.647 mm has been achieved. The coating exhibits lower hardness value (45.49 HV_0.2–114 HV_0.2) than that of a substrate (180HV_0.2) which leads to the solid lubricating properties. Pin-on-disc tribometer has been used to observe the wear behaviour of the samples and found that average wear of the coated surface is 4.56 μm as compared to the mild steel substrate (95.61 μm).