抄録
Silicon carbide (SiC) has many exceptional properties such as thermal stability, chemical inertness, low neutron absorption cross-section and high thermal conductivity. These excellent properties make SiC competent for high temperature, high pressure and high radiation environment and suitable for direct process monitoring in nuclear industries. Due to the excellent mechanical and thermal properties, silicon carbide (SiC) has been chosen as a potential cladding material for pressurized water reactor. The presence of oxygen impurity is inevitable from the fabrication process. Oxygen in SiC may reduce the mechanical properties of SiC. However, few research works has been focused on the effect of oxygen dopant to material mechanical properties. In this paper, first principle calculations are used to study the effect of interstitial or substitutional oxygen on the mechanical property of SiC. Three kinds of situations are simulated by VASP. The strain and stress curves are calculated to evaluate those doping effects. The result shows that the oxygen atoms make SiC easier to crack, and the tensile strength of SiC is reduced.
