Abstract

Ni_3Al intermetallic compound has been tested as a binder phase, in order to improve the oxidation resistance and the mechanical properties of TiC-Ni cermet at a high temperature. The wettability of Ni_3Al on TiC and the optimum sintering condition were investigated in TiC-(30, 40) vol% Ni_3Al cermets with the sintering temperature (1380~1430°C) and time (30~99 min). The results are summarized as follows: 1) Ni_3Al showed good wettability on TiC above 1400°C ; 2) The shrinkages of the specimens increased with the sintering temperature, the sintering time and the binder content, whereas the relative densities were decreased; 3) Any other phase did not appeared in the microstructures of all sintered cermets. The grain sizes of TiC became larger as the sintering temperature and the sintering time as well as the binder content increased; 4) The hardness of the cermets decreased with increase in the sintering temperature and the sintering time as well as the binder content; 5) The transverse-rupture strength of the cermets increased with the sintering temperature and the sintering time, whereas it decreased with the binder content.