Characterization of Ti-based solid solution cermets prepared by mechanically induced self-sustained reaction and subsequent pressureless sintering

Nanocrystalline (Ti, Mo)C and (Ti, W) C solid solution powders were obtained by mechanically induced self-sustained reaction through high-energy ball milling of Ti, Mo, W and graphite powders under an argon atmosphere. The synthesis process of the solid solution powders and the microstructure of the solid solution cermets were investigated. The solid solution powders formed between 2 h and 3 h of ball milling. After 8 h of milling, Mo dissolved in TiC completely but W did not. (Ti, Mo) C-Ni cermets had a weak core-rim structure, and (Ti, Mo) C solid solution grains showed a poor wettability with the binder. (Ti, W) C-Ni cermets contained some grains without a core-rim structure and showed a superior toughness. The addition of Mo improved hardness and transverse rupture strength of the solid solution cermets but reduced the toughness, and the solid solution cermets showed greater toughness than conventional cermets. (C) 2013 Elsevier B. V. All rights reserved.