Microstructures and Mechanical Properties of Al3Ti/Al Composites Produced In Situ by High Shearing Technology

Due to its low density, high strength, and stiffness the intermetallic phase Al3Ti is a good candidate as reinforcement for Al alloys. In this work, in situ Al3Ti particle reinforced Al composites are fabricated from Ti particles and Al melt via melt stirring with a high shearing mixer. Microstructure and mechanical properties are investigated. The results indicate that, owing to the high shearing effect and intensive macroscopic flow of the melt, reinforced particles are distributed homogeneously on the microscopic and macroscopic scale. Furthermore, Al3Ti particles are proved to be effective nuclei for heterogeneous nucleation of -Al, thus the grain size of the Al matrix is significantly decreased. As a result of the fine grains and the uniform distribution of Al3Ti particles, E-modulus, yield, and tensile strength of the composites are enhanced.