Enhanced mechanical properties of nanostructured (W,Ti)C-FeAl hard materials rapidly sintered by the pulsed current activated heating

摘要

In the case of cemented (W,Ti)C, Co or Ni is added as a binder for the formation of composite structures. However, the high cost of Co or Ni, the low hardness and the low corrosion resistance of the (W,Ti)C-Ni and (W,Ti)C-Co cermets have generated interest in recent years for alternative binder phases. In this study, FeAl was used as a novel binder and consolidated by the pulsed current activated sintering (PCAS) method. The advantage of this process is not only rapid densification to near theoretical density but also the prohibition of grain growth in nano-structured materials. Highly dense (W,Ti)C-FeAl with a relative density of up to 99% was obtained within 3 minutes by PCAS under a pressure of 80 MPa. The addition of FeAl to (W,Ti)C enhanced the toughness without great decrease of hardness due to crack deflection and decrease of grain size.