Development of Fe–NbC cermet from powder obtained by self-propagating high temperature synthesis

Abstract

The present work studies the development of a 30Fe–70NbC (wt-%) cermet by powder metallurgy techniques. The base powder was obtained by the process self-propagating high temperature synthesis, and this powder was modified by mechanical milling using two different approaches: comminution milling to reduce particle size (without modifying powder microstructure) and high energy milling to reduce both particle and reinforcement size in order to improve powder microstructure. Both modified powders were compacted by uniaxial and cold isostatic pressing. The compacts were sintered in vacuum at different temperatures and times, and characterised by several techniques, including the determination of density and hardness, study by XRD to determine the constituents after sintering, and a complete microstructural analysis by SEM. The present study reveals that high energy milling permits to obtain enhanced materials when compared with materials sintered from comminuted powder.