Improving Fracture Toughness of Silicon Carbide Ceramics with Nanodiamond Reinforcements

Silicon Carbide (SiC) is a superhard and strong material applied for many engineering applications including abrasives, rotating disks, bearing, high temperature coatings etc. Poor fracture toughness due to brittleness is one of the limitations that keeps SiC from widespread applications. Over the last few years, scientific and industrial interests on nanoparticle reinforced Silicon Carbide materials have grown extensively primarily because of their immense potential to improve the fracture toughness without sacrificing strengths. In this study, we have investigated the reinforcement efficiency of nanodiamond and Silicon nanoparticles in Silicon Carbide using molecular dynamics simulation. Two different arrangements of nanoparticles have been considered: (a) clustered particles ahead of the crack tip and (b) uniformly distributed particles. Mode I and Mode II fracture toughness were measured. It has been observed that infusion of nanodiamonds in Silicon Carbide improves the Mode II fracture toughness by similar to 100%. About similar to 25% improvement is observed for Mode I fracture toughness. Details will be discussed in the paper.