High-temperature oxidation behaviour of WC-FeAl composite fabricated by spark plasma sintering.

In this study, the WC-FeAl composite was synthesized by mechanical milling and spark plasma sintering. The isothermal oxidation behaviour of the WC-FeAl composite was evaluated and compared with a commercial WC-Co composite at the temperature range of 700–900  ℃ . The results showed that the oxide layer formed in the WC-FeAl composite contained FeWO 4 , FeAlO 3 , and WO 3 phases at all tested temperatures. The XRD patterns indicated that the intensity of FeWO 4 and FeAlO 3 phases enhanced with increasing the oxidation temperature. The formation of these two phases was related to the diffusion of Fe and Al elements from the binder phase to the oxide layers. As a result of the presence of FeWO 4 and FeAlO 3 phases, more compact oxide scales were formed, and the volume of voids and cracks was decreased as compared to the WC-Co composite. The plot of specific mass variations as a function of time illustrated that the mass gain for WC-FeAl composite was almost half of WC-Co composite. [ABSTRACT FROM AUTHOR]