A comparative study of spark plasma sintered TiCx-Ni3Ti/Ni cermets

Ni3Ti intermetallic has a high chemical and structural stability as well as strength at elevated temperature. It can be potentially used as a binder for TiC based cermets. In the present study, TiC0.8-14.7 vol.% Ni3Ti and TiC0.95-14.7 vol.% Ni cermets were prepared by spark plasma sintering from a TiC0.95 -NiTi and -Ni powder mixture respectively, and investigated in terms of sintering behavior, microstructure and mechanical properties. The results revealed that a fully dense Ni3Ti binder cermet with a homogeneous binder distribution was obtained after sintering for 4 min at 1100 °C, whereas a dense Ni binder cermet was obtained after sintering for 10 min at 1240 °C. The better sinterability of the Ni3Ti binder cermet could be explained based on calculated ternary phase diagrams. The Ni3Ti and Ni binder cermet exhibited a similar titanium carbide grain size. The E-modulus, hardness and bending strength of the Ni3Ti binder cermet were lower than for the Ni binder cermet, whereas the fracture toughness was higher.status: publishe