Stacking faults and grain boundaries of Ti_3SiC_2 have been investigated by means of high-resolution electron microscopy. The stacking faults were found to result from insertion of additional TiC layers, instead of dissociation of dislocations conventionally observed in other materials. The stacking faults with many TiC layers inserted can also be viewed as TiC platelets. A glass phase is not formed at large-angle grain boundaries of Ti_3SiC_2, manifesting the weak directionality of bonding in Ti_3SiC_2. The results also indicate that the softening of Ti_3SiC_2 at high temperatures does not result from intergranular glass films but from an intrinsic property of Ti_3SiC_2. Moreover, it was found that one grain contacts the other with its base plane for most of the investigated grain boundaries.
展开▼
