Improvement of thermal conductivity of WC-FeAl hard materials by elimination of oxide materials

Abstract

The dependence of thermal conductivity in tungsten carbide- iron aluminide (WC-FeAl) hard materials on oxygen contained in the pre-sintered powders was investigated. The control of oxygen concentration in the hard materials was done by changing fabrication processes including heat treatment of raw WC powder. Although thermal conductivity of the hard materials strongly depended on the average WC grain size, it was apparently improved by reduction of oxygen Concentration. The maximum thermal conductivity was 169 W (mK)−1 with low volume fraction of FeAl binder (10 vol%Fe0.6Al0.4) to total WC-FeAl. The hardness and transverse rupture strength had negative relationship with the average WC grain size, indicating that they also had negative relationship with thermal conductivity. The improving technique such as uniform powder mixing with suppressing powder oxidation is required to fabricate WC-FeAl hard materials of high transverse rupture strength and thermal conductivity.