Enhancement of Wear and Corrosion Resistance of ZA27/Nanographene Composites Produced by Powder Metallurgy

In this study, the effect of the nanographene content on the wear and corrosion behaviors of nanographene-reinforced ZA27 alloy metal matrix composites was investigated. The reinforcement containing 0.125%, 0.25%, 0.5%, 1%, 2% and 3% by weight of nanographene particles was examined. The ZA27/nanographene composites reinforced with nanographene particles were produced using mechanical milling and hot pressing method by powder metallurgy. Wear tests were conducted using a ball-on-disk-type wear testing apparatus under dry conditions and loads of 2 and 10 N at a sliding speed of 100rpm. The influence of corrosion on the surface appearance and microstructure of ZA27/nanographene composites was evaluated by potentiodynamic polarization scans in 3.5% NaCl solution. Morphological, microstructural, worn and corrosion surface examinations were performed by scanning electron microscope equipped with energy-dispersive X-ray spectrometer and X-ray diffractometer. Results of the wear tests revealed that the wear loss of composites decreased with an increase in the nanographene content, while increased with an increase in wear load. The electrochemical polarization measurements showed increased corrosion resistance in the composites by the increase in the nanographene content. The electrochemical corrosion tests indicated that the corrosion rate value of the ZA27/nanographene composites decreased from 16.47 to 1.745mpy with increasing the nanographene content from 1 to 3%.