| Summary: | The present work investigates the deposition and tribological behavior of electroless Ni-B-Mo coatings under dry and lubricated conditions. The effect of heat treatment (350°C, 400°C and 450°C for 1 hour) on the coating microstructure and tribological behavior is observed. In as-deposited condition the coatings are amorphous and present a nodulated surface morphology. Heat treatment results in crystallization of the coatings. Vicker’s micro-indentation tests indicate the coatings have high thermal stability. In comparison with as-deposited condition, heat treatment at 350°C results in an improvement in wear resistance and coefficient of friction (COF) of the coatings under dry as well as lubricated condition. Heat treating at 400°C or 450°C does not cause a significant improvement in wear rate of the coatings. In fact, lubrication results in a significant improvement in tribological behavior of the coatings. Heat treatment results in degradation of corrosion resistance of the deposits in 3.5% NaCl solution. An effort has been also made to correlate the microstructure and tribological behavior / corrosion resistance of Ni-B-Mo coatings.
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