Enhancement of Coating Thickness and Microhardness of Ni-Sic Nanocomposite Coatings for the Variation in Bath Parameters

摘要

Ni-Sic nanocomposite coatings were prepared on a MS substrate by electrocodeposition process. The electro-co-deposition was carried using sulphamate bath. In the present work the effect of electrochemical bath parameters such as bath temperature, bath loading and current density on physical and mechanical properties of Ni-based SiC composite coating on mild steel substrate was studied. SiC loading, Current density and bath temperature were varied and the coating thickness was measured using Elektro Physik thickness gauge. The mechanical properties of the electrocodeposited Ni-SiC coatings containing ceramic particles are very much dependent on various factors like bath used, current density, duration of deposition, Thickness of the coating, bath temperature etc. The effects of current density, bath temperature and SiC nanoparticles concentration in the plating bath on the hardness of the coatings were determined by microhardness tests using Vicker’s microhardness tester. The Experimental results shows that, the microhardness of the codeposited coating increases with the increase in the current density and attains a maximum at the SiC concentration of 6 g/l. The decrease in the microhardness at higher concentrations may be due to agglomeration of nano sized particles in the plating bath.