Effect of nano-SiC incorporation on mechanical properties of micro and nano-structured Ni-Co electrodeposits.

ABSTRACT

Ni-Co/SiC nano-composites were electrodeposited from modified Watts bath containing SiC particles with 50 nm average size, SDS as surfactant and saccharin as grain refiner in appropriate amounts. The effect of grain size and nano-particle incorporation on microstructure and mechanical properties of electrodeposits was investigated. The grain size of the deposits was calculated from X-ray diffraction (XRD) patterns using Williamson-Hall equation and surface morphology of the coatings was studied by means of scanning electron microscopy (SEM). The mechanical properties of electrodeposits were investigated by Vickers microhardness and tensile tests. The results indicated that incorporation of SiC nano-particles increased the microhardness and yield strength of micro-grained deposits due to the change in crystallographic texture, decrease in grain size as well as dispersion hardening. But dispersion hardening mechanism could not be confirmed in nano-structured deposits. Moreover, the increase in the concentration of uniformly dispersed SiC particles initially improved and then decreased the elongation to failure of coarse-grained deposits while a continuous increase was observed for nano-structured deposits.