Improving TiB2 dispersion in Al-Si composites by interfacial projection: High-throughput first-principles calculations and experimental verification

Abstract

The dispersion of reinforced particles is crucial in improving the mechanical properties of ceramic particles reinforced Al matrix composites. In this work, a novel interfacial projection strategy was proposed to improve the dispersion of TiB2 particles in Al-Si composites through high-throughput first-principles calculations with the experimental verification. Firstly, the Al(111)/TiB2(0001) interface model was constructed. Then, the pre-substitution of Si at 2 at. % concentration was employed to simulate the solutionized Al matrix. Secondly, alloying behaviors of 55 elements (10 substitution sites per element) in the Si-Al(111)/TiB2(0001) interface were studied by high-throughput first-principles calculations in terms of the relative interface formation energy and the relative work of adhesion. With these values, a theoretical alloying map for evaluating the dispersion ability of these alloying elements was plotted. Accordingly, the copper mold experiments were conducted to validate the theoretical alloying map. Based on the electron analysis, the enhanced interface bonds by alloying primarily attributed to electron accumulations around Si atom, indicating that the pre-substitution Si atom was vital for a reliable simulation result. Generally, this interfacial projection strategy provides a precise and potent approach in designing high-performance Al matrix composites, and should be applicable to other reinforced particles.