High temperature (900 – 1300°C) mechanical behaviour of dendritic web grown silicon ribbons: - strain rate and temperature dependence of the yield stress

Abstract The study indicates that the deformation characteristics of silicon ribbons (dendritic web grown) at high temperature do not represent a simple extension of the low temperature behaviour. Below 1200°C, where the deformation is mostly thermally activated, normal trends are observed. Above 1200°C, a strengthening effect is observed. This phenomena is a strong function of the strain rate, being the most significant for the slowest strain rate. The increase in the strength levels can be attributed to the diffusion of oxygen atoms (excess interstitial oxygen) to the dislocation cores which effectively locks the dislocations.