Electrodeposited SiC-graphene oxide composite in nickel matrix for improved tribological applications

Electrodeposited nickel matrix embedded with silicon carbide (SiC) and graphene oxide (GO) particles were prepared through pulsed electro-deposition. Taking advantages of the excellent tribo-mechanical properties of GO and SiC, excellent anti-wear and frictional properties are expected when SiC and GO particles were embedded in the Ni matrix. For this purpose, nano-SiC particles were first grafted within Ni matrix to engineer Ni-SiC coatings. Further GO particles were added to the Ni-SiC bath to prepare Ni-SiC-GO composite coating. The structure, composition, and morphology of the Ni-SiC and Ni-SiC-GO were characterized by Raman spectroscopy, XRD, AFM, FE-SEM, EDS and water contact angle measurements. The results revealed that SiC and GO particles were successfully incorporated in the Ni matrix. Addition of GO to the composite matrix reduced the water contact angle from 69.2 degrees to 58.9 degrees, thereby confirming hydrophilic nature of Ni-SiC-GO due to the presence of polar oxygen functionalities. The tribological tests of the coatings were studied under dry sliding condition using a linear reciprocating ball on plane sliding microtribometer with varying sliding speed and the wear mechanisms of these coatings were also investigated. The addition of SiC into the Ni matrix enhanced its wear resistance with a poor frictional behaviour. However, incorporation of GO into Ni-SiC-GO coatings reduced the coefficient of friction (COF) substantially with an adaptable anti-wear behaviour. Increase in sliding speed was found to have a detrimental effect in the wear and friction behaviour of the coatings. The superior tribological properties of the Ni-SiC-GO were attributed to the synergistic effects of SiC and GO. This work offers a unique methodology to design durable nanocomposite coatings for industrial tribological applications.