Processing of B 4 C particulate reinforced with aluminium die-casting-10 using automatic feeder stir squeeze casting method

Abstract

This study investigates the fabrication of aluminium die-casting (ADC-10) composites with varying weight percentages of boron carbide (B₄C) particles, using Al-5Ti-B as a grain refiner through mechanical automatic feeder stir squeeze casting process. Five compositions are developed: pure ADC-10 and blends with 0.5%, 1%, 2%, and 3% B4C, designated R-0, R-0.5, R-1, R-2, and R-3, each containing Al-5Ti-B grain refiner. The samples having 2 wt.% of B₄C exhibit maximum grain refinement. As a result significant enhancement in hardness and toughness values are observed. However, the increase in higher reinforcement level (3 wt.%) leads to particle agglomeration thereby negatively impacting the mechanical properties. Fracture studies have indicated increased brittle failure with more B₄C content, while the best specific strength and elongation are achieved at sample containing 2 wt.%, B₄C. This can be attributed to improved interfacial strength and uniform particle distribution. Overall, the combination of B₄C reinforcement and grain refinement with mechanical stir casting notably enhanced the mechanical strength of the composites, underlining the importance of particle uniformity and nucleation site development in improving mechanical properties.