Effect of heat treatment on mechanical and tribological characteristics of Electroless Ni-P deposits

In the present paper, mechanical and tribological characteristics of as-deposited and heat-treated Electroless Ni-P coatings were investigated. Medium phosphorus Ni-P coatings were deposited on mild steel substrate using an acidic bath and subjected to heat treatment at 400°C in a tubular furnace. Surface morphology and elemental analysis of the coatings were carried out using Scanning electron microscope (SEM) and Energy dispersive X-ray spectroscopy (EDS) analysis respectively. Dry sliding wear characteristics of the coatings were investigated by linear reciprocating ball on flat tribometer using AISI E52100 Steel ball as a counter body at room (25±2°C) and elevated temperature (300°C). Hardness results showed significant improvement in the surface hardness of coatings on heat treatment. Low friction coefficient and high wear rate were observed at elevated temperature in comparison of those of tests conducted at room temperature for both as-deposited and heat-treated coatings. Best tribological performance is observed for heat-treated coating tested at room temperature.