The tribological characteristics of electroless NiP coatings

The utilization of electroless NiP (EN) coating process in various industri es such as printing, textile, oil and gas, food, electronics, automotive, a erospace, chemical, and mining has witnessed a tremendous increase during t he last few decades. The endearing characteristics of EN coatings include e xcellent corrosion and wear resistance, superior mechanical and electrical properties, uniform coating thickness, and outstanding surface finish prope rties. In the present work, samples of 1018 substrate having various levels of sur face roughness were coated with low, medium, and high phosphorus EN coating s. The different substrate surface morphologies were obtained using differe nt machining parameters. The effects of EN coatings on the tribological and morphological properties of the substrate material were investigated using surface roughness and hardness measurements, wear and coefficient of frict ion tests, optical microscopy (OM), and scanning electron microscopy (SEM). It was found that the surface roughness characteristics of substrates can be enhanced and their coefficients of friction (COFs) significantly altered by EN coatings. The results further showed that, unlike conventional elect roplated deposits, EN coatings do not subvert the substrate surface shape a nd profile even for large thickness coats. It was also found that the wear resistance of EN coatings is significantly affected by heat treatment. (C) 2001 Elsevier Science B.V. Ah rights reserved.