Microstructures and Mechanical Properties of TiC/Al–Si–Fe Composite with Ti–C Powder Mixture Prepared by Contact Reaction Method

This article investigates in situ TiC particle‐reinforcement Al–Si–Fe matrix composites prepared by the contact reaction method. The addition of Ti–C to alloys results in the formation of β‐Fe and significantly refined the eutectic Si phase. Meanwhile, the exothermic reaction of C accelerates generation velocity of TiC. The refinement of the Al3Ti phase is attributed to refinement of α‐Al, which expedites solidification speed and prevents the further diffusion of Si atom, resulting in the bulk of the primary Si phase is formed locally. The best refinement effect of microstructure is obtained when the mixing powder addition content is 1.0 wt% and the Al‐12Si‐1Fe alloy has maximum tensile strength. The appearance of TiC is regarded as underlying reason for the re‐enhancement of mechanical properties.