DIFFUSION-INDUCED RECRYSTALLIZATION OF TIC

When large TiC particles (30 mu m in average) are embedded in Cr3C2 po wders and heat-treated at 1550 degrees C, recrystallization occurs fro m the surface of the TiC particles, and they are finally replaced by a n entirely new set of (Ti,Cr)C alloy grains. The observed recrystalliz ation is greatly suppressed when ZrC is added in the Cr3C2 matrix. The results are in agreement with the prediction that a lattice mismatch due to the diffusion of Cr and resultant formation of misfit dislocati ons are the major cause of recrystallization. The diffusion induced re crystallization (DIR) process is observed in detail by using a transmi ssion electron microscope.