Deposition and Microstructural Characterisation of GLC Coatings on AZ31 Magnesium Alloy

Magnesium alloy is one of the most attractive light alloys for transportation systems because of their lightness and ease of recycling. However, surface degradation (such as corrosion and wear) is the major technical barrier to their wider applications. To this end, graphite-like carbon (GLC) coatings were deposited on AZ31 magnesium alloy substrate by closed filed unbalanced magnetron sputtering ion plating and detailed characterisation was carried out using SEM, TEM, XPS and pin-on-disc testing. Special attention has been paid to the effect of such critical processing factors as ion cleaning of the substrate, interface layer materials and the bias on the microstructure, interface, coatings/substrate bonding strength and the properties.