화학공학소재연구정보센터
Applied Surface Science, Vol.467, 567-579, 2019
Synthesis and characterization of novel Cu, Cu-SiC functionally graded coating by pulse reverse electrodeposition
A Cu based functionally graded coating (FGC) has been deposited on an annealed Cu substrate by galvanostatic pulse reverse electrodeposition (PRED) route. The objective is to develop a hard surface with highly ductile and conducive interior. The cathodic current density (CCD) has been increased stepwise (from 50 to 200 mA/cm(2) ) to synthesize Cu FGC on an annealed Cu substrate. It has three layers of Cu coating (20 mu m each) with a gradual reduction in crystallite size along the thickness. Two layers of Cu-SiC nanocomposite coating with an increment in the amount of incorporated SiC nanoparticles (from 2 to 7 vol%) are electrodeposited on Cu FGC. This is done by introducing bath agitation (350 and 450 rpm) during deposition at CCD of 200 mA/cm(2) , which has resulted in Cu, Cu-SiC FGC with five layers (12 mu m each). SiC nanoparticles are used to impart hardness to the coating through dispersion strengthening. The Cu, Cu-SiC FGC possesses higher hardness ( similar to 3.8 GPa), lower residual compressive stress ( similar to 291 MPa), and lower surface roughness ( similar to 0.9 mu m) as compared to electrodeposited single layer Cu-SiC nanocomposite coating. With such properties Cu, Cu-SiC FGC on annealed Cu substrate can serve as a novel prospective electrical contact material.