A Wear-Resistant Coating for Aluminium-Silicon Alloys Using Microarc Oxidation and an Application to an Aluminium Cylinder Block

A method of microarc oxidation (MO) on aluminium-silicon alloys has been developed to provide a wear-resistant coating for the internal surfaces of an automotive cylinder block cast from aluminium-silicon alloys. The results obtained in this study demonstrate the effect on MO coat quality by a pre-processing heat treatment prior to MO. The treatment is carried out to change the shape and size of the eutectic and/or primary silicon particles to form the required microstructure. This MO method can be applied to improve the wear-resistance of aluminium-silicon alloys provided the necessity of maintaining low wear on the counterbodies contacting with coat is taken into account.