Tailoring the Mechanical Properties of X–C–Si (X = Al, Mg) Alloys for Aerospace and Automotive Industries: An ab Initio Study

Abstract

Silicon carbide (SiC) is a strong and adaptable material that has a good number of uses, including in the automotive industry for power electronics and electric vehicle components; abrasive material used in grinding and cutting; and in the production of refractory materials. These applications are due to the superior properties of SiC, which include high hardness, chemical inertness, and mechanical strength. However, its brittleness, low fracture toughness, as well as relatively high density hinder it from being applied in other areas such as in making bodies of airplanes as well as automobiles. Through careful alloying with lighter materials, this shortcoming can be addressed. Using an ab Initio approach, this study examined the mechanics of magnesium (Mg) and aluminum (Al) alloys with SiC as a potential candidate for the automotive and aerospace industries. Al or Mg atoms were substituted for some of the carbon atoms in the SiC to complete the alloying process. The results showed that the alloys had lower bulk moduli, shear moduli, Youngs moduli, and density compared to those of SiC. However, their ductility and fracture toughness increased. Although the mechanical properties reduced, they were found to be still much better than those of the common alloys for the aerospace. The alloys were thus found to be suitable for the construction of the shell of the airplanes, owing to their superior ductility and fracture toughness.