Effect of α-Al2O3 coatings on the interface of Ni/SiC composites prepared by electrodeposition

This paper describes an investigation on the effect of α-Al2O3 coating on the interface between nickel and SiC particle. Uniform, dense and well-adhered α-Al2O3 coatings were obtained on the surface of SiC particles by sol–gel technology. The nickel-based composites reinforced with α-Al2O3-coated SiC particles (CSp) or uncoated SiC particles (UCSp) prepared by composite electrodeposition were heated at 600 °C to study the reactivity and the resulting interfaces. The results showed that the Ni/CSp composites presented excellent thermal stability without interfacial reaction, while nickel silicide formed in the Ni/UCSp composites. It indicated that high-temperature interfacial reaction between SiC particles and nickel matrix was efficiently inhibited by the α-Al2O3 coatings. Moreover, great differences of the local mechanical properties of interfaces were observed by the nanoindentation characterization.