Refining and reinforcing effects of TiC-Al2O3/Al ribbons inoculant on Al–Si–Mg–Ti alloy

Abstract

In this study, TiC-Al2O3/Al ribbons inoculant were prepared by mechanical alloying, spark plasma sintering (SPS) and melt spinning. Adding 5vol.% TiC-Al2O3/Al ribbons to an Al–Si–Mg–Ti (ASMT) alloy melt significantly refined the α-Al grains from 28.5 μm to 14.9 μm. In addition, the morphology of the eutectic silicon were modified and optimized, changing from needle-like silicon to spherical silicon. Adding the TiC-Al2O3/Al ribbons significantly improved the mechanical properties of TiC-Al2O3/Al–Si–Mg–Ti (TAASMT) alloy, including its elastic modulus (EM), yield strength (YS), ultimate tensile strength (UTS) hardness, and elongation which were increased by 5.4%, 18.4%, 32.7%, 8.3%, and 62.3%, respectively. These increases in the mechanical properties could be attributed to the intracrystalline reinforcement of the Al2O3 and TiC nanoparticles, well-bonded particle/matrix interface, modification of the eutectic silicon phases, and synergistic effects of the Orowan strengthening, Coefficient of thermal expansion (CTE) mismatch strengthening, load transfer, grain refining strengthening, and geometrically necessary dislocations (GND) strengthening.