Densification of TiB₂-Fe based cermets during liquid phase sintering

The densification behaviour of TiB₂-Fe based cermets during liquid phase sintering in argon was studied in relation to wetting charactertics, The effect of TiB₂ powder properties and sintering condition, on the sintering behaviour, were also investigated. It was found that a liquid formed at about 1510K by a pseudobinary eutectic reaction of TiB₂-Fe, the liquid formation caused a rapid densification of the compacts. However, a fine TiB₂ powder with a high purity showed good sinterability, while coarse and less pure powder showed poor sinterability. Appreciable densification started at the eutectic liquid formation, around 1510K and was kept on up to 1973K to attain full density. The wide temperature range for effective densification, from 1510∼1973K, will mean that the rearrangement is dominated by slow process of liquid penetration and extensive wetting. Higher densities were obtained in the TiB₂-SUS316L system due to improved wettability associated with the actions of Ni, Cr and Mo. It was found that the liquid penetration and wetting kinetics dominates the densification in the wide temperature range.