The influence of multipass friction stir processing on the corrosion behavior and mechanical properties of zircon-reinforced Al metal matrix composites

Abstract

Zircon-reinforced Al metal matrix composites were fabricated by friction stir processing (FSP). Composite materials were analyzed to characterize their microstructure, mechanical properties and corrosion resistance. The number of FSP passes was found to have a significant effect on the microstructure and strength of the composite specimens. Multipass friction stir processing of the composite specimens promoted grain refinement in the base metal and resulted in a uniform dispersion of the reinforcement particles. In addition, increasing the FSP pass number from one to three increased the composite density. Also, corrosion resistance of the composites was severely influenced by the number of FSP passes and presence of reinforcement particles. While, corrosion performance of the composite materials was significantly enhanced as the number of FSP passes increased to two and three passes, a more number of FSP passes reduced the corrosion resistance of composite materials. It was found that process parameters could be easily optimized to enhance the mechanical properties and corrosion resistance of the zircon-reinforced Al metal matrix composites during FSP.