Liquid‐Phase Sintering of TiC‐Ni Composites

Abstract

The sintering of TiC‐Ni particle compacts was studied with specific attention to effects of processing conditions. Densification was progressively inhibited with the increasing additions of free carbon to the system. These results are explained on the basis of changes in the eutectic reactions in the system, reduced solubility of TiC in the Ni‐rich liquid, and decreased wetting of the solid by the liquid. Presintering hydrogen heat treatment reduced the carbon content of the TiC‐Ni compacts and led to reduction in sintering rates and elevated temperatures of liquid‐phase formation. Wetting experiments with hydrogen‐treated materials showed a time‐dependent wetting angle. These results are discussed based on wetting theory and reactions predicted by the equilibrium ternary‐phase diagram.