Mechanical Behavior of Silicon Carbide Under Static and Dynamic Compression

Abstract

This paper compared the mechanical behavior of 6H SiC under quasi-static and dynamic compression. Rectangle specimens with a dimension of 3 × 3 × 6 mm3 were used for quasi-static compression tests under three different loading rates (i.e., 10−5/s, 10−4/s, and 10−3/s). Stress–strain response showed purely brittle behavior of the material which was further confirmed by scanning electron microscopy (SEM)/transmission electron microscopy (TEM) examinations of fractured fragments. For dynamic compression, split Hopkinson pressure bar (SHPB) tests were carried out for cubic specimens with a dimension of 6 × 6 × 4 mm3. Stress–strain curves confirmed the occurrence of plastic deformation under dynamic compression, and dislocations were identified from TEM studies of fractured pieces. Furthermore, JH2 model was used to simulate SHPB tests, with parameters calibrated against the experimental results. The model was subsequently used to predict strength and plasticity-related damage under various dynamic loading conditions. This study concluded that, under high loading rate, silicon carbide (SiC) can deform plastically as evidenced by the development of nonlinear stress–strain response and also the evolution of dislocations. These findings can be explored to control the brittle behavior of SiC and benefit end users in relevant industries.

Engineered Silicon Carbide Three-Dimensional Frameworks through DNA-Prescribed Assembly

“…Nanostructured silicon carbide (SiC) has attracted much attention due to the potential applications related to their excellent mechanical strength, chemical stabilities, optical and electronic properties. − Particularly, nanoarchitectured Si and SiC are active areas of exploration in the fields of photovoltaics and optoelectronics. For example, due to the stability of the SiC bond and its wide (>3 eV) band gap, it is suitable for high-temperature operation in devices. − Mechanically, silicon carbide is a high strength material, which has been shown to enhance the strength of composite materials when incorporated into the nanostructure of nanowires and as a silicon substitute in microelectromechanical systems (MEMS). − Precisely formed 3D nanoscale architectures also hold enormous potential for engineering of nanoporous materials with mechanical, electromechanical, mass transport, and optical applications. − Particularly with respect to optical and photonic applications, the high refractive index of silicon carbide and silicon in comparison to silica drives the need to create tailorable 3D synthesis pathways to enable fabrication of complexly designed photonic devices. ,, …”

A multiscale-indentation study of deformation and fracture in 6H polycrystalline silicon carbide

“…In addition, it was found that intergranular cracking leads to a higher fracture toughness than that for transgranular cracking due to a greater area involved in fracture for intergranular cracking [7]. Additionally, Zhang et al [8] carried out both quasi-static and dynamic compression on polycrystalline 6H-SiC, it was found that brittle fracture was the major failure mode under quasi-static compression, whereas evident plastic deformation (dislocations, kinks, etc.) was the dominating deformation mechanism under dynamic compression.…”