Shock wave sintering of Al/SiC metal matrix nano-composites: A molecular dynamics study

Mechanical properties of nano-composites produced by shock wave sintering of aluminum and silicon carbide nano-powders are investigated using Molecular Dynamics (MD) simulations. In this regard, the shock wave response of aluminum and silicon carbide nano-particles, arranged in a BCC super-lattice, is studied via the NPHug Hugoniostat method. Moreover, the effect of the initial hydrostatic compaction of powders as well as the cooling rate of the shocked material on the mechanical properties of the shock-sintered nano-composites is investigated. Employing the Hugoniot curves corresponding to the powders, it is concluded that an initial hydrostatic pressure, leads to a less temperature rise and higher shock wave velocity. Moreover, the uniaxial loading test simulation is utilized to determine the mechanical properties of the final products. It is illustrated that increasing the shock pressure leads to an enhancement in the mechanical properties as a result of the formation of fiber reinforced nano-composites. The initial pressure exerted on the nano-particles, however, results in weakening of the sintered nano-composite. Furthermore, it is shown that an appropriate cooling rate can result in the activation of the diffusion mechanism after the shock wave passage which is helpful in increasing the bonding strength of nano-particles. (C) 2016 Elsevier B.V. All rights reserved.