State‐Variable Analysis of Inelastic Deformation of TiC Single Crystals

The log σ‐log ɛ data obtained from load relaxation experiments on TiC single crystals, at 900° to 1400°C, were analyzed in terms of Hart's two‐branch rheological model. The analysis verified the existence of a mechanical equation of state within the ranges of stress, strain rate, and temperature employed. Straight and clustered dislocations dominated the micro‐structure of samples at low temperatures, while well‐developed cell structures dominated the microstructure of samples at high temperatures. The observed changes in log σ‐log ɛ curves and the dislocation structure both indicate that, in addition to the glide‐controlled mechanisms, climb/cross‐slip‐controlled mechanisms contribute significantly to the plastic flow with increasing temperature.