Effect of SiCp as Reinforcement on the Corrosion Behavior of Cast Al-Mg Matrix

Abstract

Metal matrix composite (MMC) are engineered materials manufactured by the action of incorporated reinforcement materials into metal matrix. As a result, stiff and hardened reinforcing phase in metallic matrix is obtained. The matrix includes a wider range of non-ferrous structures; meanwhile reinforcing phases comprise hardened nonmetallic particulates. The purpose of this paper is to investigate microstructural and electrochemical behavior of Al-Mg matrix reinforced with SiC particles (SiCp). The aluminum metal matrix composite was manufactured by the foundry vortex method. In the vortex process, SiC particles mixed into steel tubes at 1500 rpm were added to molten Al-Mg as-cast alloy. The metal-matrix composite (MMC) was characterized with the purpose of studying chemical interactions of SiC particles with the metal-matrix and its respective effect in electrochemical behavior. Results show that anodic dissolution in the cast Al-Mg matrix was accelerated by the formation of a non-stable oxide layer exhibiting partial protection with small resistance to polarization conditions, while the corrosion phenomena in Al-MMC was inhibited by the addition of silicon carbide particles