DISLOCATION DISSOCIATION IN TITANIUM CARBIDE CRYSTAL

In order to clarify whether the dislocations in a titanium carbide crystal dissociate or not, single crystals with various C/Ti atom ratios, 0.59 approximately 0.95, were deformed and dislocations introduced by deformation were observed by transmission electron microscopy using weak-beam and high resolution techniques. It is found that the dislocations dissociate into partials. The dissociation width increases with the decrease in C/Ti ratio from 1.75 nm for TiC0.95 to 4.2 nm for TiC0.59, which leads to the stacking fault energy from 130 to 300 mJ/m2. The effects of image force and imaging conditions for the weak-beam observation on the observed dissociate width are discussed for precise estimation of the stacking fault energy.