Tuning the structural and mechanical properties of SiC-Li and SiC-Na alloys for aerospace application: an ab initio study

Abstract

Aluminum (Al) and its alloys are popular in the aerospace industry due to their high strength-to-weight ratio, corrosion resistance, and ductility. However, these properties (extreme ductility and malleability) can compromise corrosion resistance, making them susceptible to dents and scratches. Silicon Carbide (SiC) is a promising alternative to Al and it alloys due to its higher Youngs modulus and excellent wear resistance, although it has the drawbacks of brittleness and higher density. This study investigated the structural and mechanical properties of SiC alloyed with lithium (SiC-Li) or sodium (SiC-Na) using ab initio calculations with the aim of tuning the structural and mechanical properties of SiC. Modeling was done using Burai software, which offers a friendly graphical user interface for Quantum ESPRESSO, thus facilitating the creation of input files, visualization of crystal structures and analysis of results. The results from this study showed that the addition of Li and Na lowered the density as well as the mechanical properties of SiC but still being favorably better than those of Al and its alloys, suggesting that the modeled alloys could potentially replace the traditional Al and its alloys in the aerospace industry. Further experimental studies are needed to validate these findings and to explore the possibility of simultaneous alloying of SiC with both Li and Na for enhanced performance.