Effect of sintering temperature and time on corrosion characteristics of aluminum matrix composites

Aluminum matrix composites outperform traditional alloys in terms of mechanical properties and corrosion resistance. Silicon carbide is the main reinforcing material in aluminum-based composites that have developed rapidly in recent years. In this investigation, aluminum-silicon carbide composites were prepared through powder metallurgy with 10 and 20 wt.% of silicon carbide reinforcement. The influence of the SiC content, sintering temperature, and sintering time on the corrosion behavior of prepared Al-SiC composites in 0.5 M hydrochloride acid solution was assessed. The surface microstructure was characterized by scanning electron microscopy with energy dispersive analysis and X-rays. The experimental results demonstrated how the sintering parameters can affect the corrosion characteristics of sintered samples. The electrochemical analysis curves showed that when increasing the sintering temperature and sintering time, there is a possibility of self-repair of damaged passive film on the surface while further reinforcing of the composite with silicon carbide prevents penetration of chloride ions. The SEM images and EDS analysis of composite surfaces after being corroded in 0.5 M HCl revealed that increasing the sintering temperature and prolonging the sintering time reduce the pitting corrosion of composites.