Effect of pulse frequency on electrodeposition behaviour of Ni-SiC composites

In the present paper, the effect of pulse frequency on electrodeposition behaviour of Ni-SiC composites was examined. Based on the impedance results of the composite, an equivalent circuit was used to describe the electrochemical system under different pulse frequencies. It was found that the simulated instantaneous peak current increased with decreasing pulse frequencies. A high peak current was known to favour nucleation and fine grain size. Experimental results revealed that the nickel grain size decreased with decreasing pulse frequency, and the volume fraction of SiC was relatively independent of pulse frequency. Microhardness and nanoindentation tests were also performed, and it was found that the hardness and the elastic modulus of the composite were dependent on the pulse frequency, and the phenomena could be explained by its change in grain size. The equivalent circuit was shown to be able to describe the coelectrodeposition system.