Production and indentation analysis of WC/Fe-Mn as an alternative to cobalt-bonded hardmetals

An iron-manganese (Fe-Mn) alloy-bonded tungsten carbide hardmetal, WC/Fe-13.5 wt.% Mn, was produced in various combinations of binder phase by using powder metallurgical routes. This was done in order to provide lower-cost hardmetals and to offer a nontoxic alternative to cobalt (Co)-based materials. The outcome of this effort has been the preparation, at acceptable sintering temperatures, of a Fe-Mn bonded WC with a fully austenitic binder phase. Vickers indentations on the hardmetal substrates produced Palmqvist-type cracks, The variation of Vickers hardness with sintering temperature was investigated for WC bonded with 15 and 25,vt.% Fe-Mn alloys. Mechanical property evaluations showed that the alloys possess higher hardness and slightly lower fracture toughness values than the equivalent of Co-bonded grades. This fact could lead to the use of such hardmetal alloys in mining and wear-resistant applications with better reliability. (C) 2001 Elsevier Science Inc. All rights reserved.