Defect structure in single crystal titanium carbide

Abstract

The defects and crystallinity of as-grown and annealed TiC_x (grown by the high-pressure float-zone) were examined by TEM and double crystal x-ray rocking curves. Three types of subboundaries and planar defects within subgrains were observed in as-grown TiC_x. Subboundaries are classified by structure as (i) wide-extended, fault-like defects (WEFLD's), (ii) edge dislocation arrays, and (iii) dislocation networks. Planar defects were observed at dislocation nodes of subboundaries and also within subgrains; this is the first reported observation of planar defects within TiC_x subgrains. The misorientation and/or density of subgrains in TiC_x was reduced significantly by annealing at 2300 °C in contact with graphite.