Effect of Fiber Reinforcement on Corrosion Resistance of Mg AM60 Alloy-based Composites in NaCl Solutions

摘要

There is great interest in developing low-cost, magnesium-based MMCs because of their high stiffness-to-weight ratio for aerospace and automotive applications. However, corrosion resistance of metal-matrix composites is often a concern for components to be used in harsh environment. In this study, the corrosion behavior of Al_2O_3 fibres reinforced magnesium AM60 composite, in aqueous solutions containing various concentrations of NaCl, was studied in comparison to that of matrix AM60 alloy by potentiodynamic polarization measurements. The microstructure of the composite and matrix alloy AM60 before and after corrosion testing was analyzed by optical microscopy, and scanning electron microscopy (SEM). The results show that the presence of Al_2O_3 fiber deteriorates the corrosion resistance of the matrix magnesium alloy AM60. The effect of Al_2O_3 fiber reinforcement and NaCl concentrations on the corrosion behavior of the composites are discussed. The corrosion mechanisms of the composite are proposed in light of metallographic observation on the formation of corrosion products.