1991 Volume 32 Issue 10 Pages 951-956
The growth behavior of carbide particles during liquid phase sintering was examined in TiC–Ni and TiC–Mo2C–Ni alloys with various Ni contents. The grain growth of TiC–Ni was markedly retarded by an addition of Mo2C. The linear relationship between the cube of mean particle size and heating time was observed in these alloys. The growth rate had a maximum near 10%Ni for TiC–Ni, but monotonously increased with increasing Ni content for TiC–Mo2C–Ni. The growth constant of these alloys was much lower by a factor of 103–104 than the rate constant expected from the diffusion-controlled growth model. The microstructural observation revealed that the growth of carbide particles took place under nearly a constant particle contact. The presence of contiguous boundaries at particle contact was considered to be an origin of sluggish grain growth in these alloys. The grain growth behavior could qualitatively be explained by assuming that the contiguous boundaries restrict the migration of solid/liquid interfaces and thus the grain growth is suppressed.
