A study on microstructure and mechanical properties of in-situ processed Aluminum alloy composites

Abstract The combined influence of aluminum–silicon (Al-Si) alloys along with an in-situ titanium boride (TiB2) particulate reinforcement is beneficial for obtaining improved mechanical properties and physical properties. In this paper is presented and discussed the results of a recent study on an Al-Si alloy based metal matrix composites containing different volume fraction of in-situ developed TiB2 particulate reinforcements that were successfully synthesized using a combination of inorganic salts at a temperature of 800 °C. Noticeable enhanced mechanical properties, to include hardness and tensile properties, were successfully achieved in comparison with the unreinforced alloy. Microstructural characterization of the as-synthesized composites was conducted using a field emission scanning electron microscope (FESEM) and x-ray diffraction analysis (XRD). Careful observation of the microstructure revealed an observable change in grain size of the aluminum–silicon matrix due to the presence and distribution of the reinforcing TiB2 particulates through the aluminum–silicon alloy. The reinforcing TiB2 particles were either hexagonal in shape or spherical in shape. The use of intermittent stirring during synthesis did exert an influence on overall distribution of the reinforcing particles through the microstructure of the composite material.