Microstructure and Its High Temperature Oxidation Behavior of W-Cr Alloys Prepared by Spark Plasma Sintering

Abstract W-10 wt.% Cr (W-10Cr) and W-20 wt.% Cr (W-20Cr) alloys were fabricated through mechanical alloying and spark plasma sintering technology. The microstructure of W-Cr alloys was characterized by XRD, SEM, TEM. The W-20Cr alloy significantly increased the microhardness from 333.5 HV of pure W to 961.3 HV. Oxidation experiments at 800 °C and 1000 °C confirmed that W-20Cr alloy shows better oxidation resistance. A suitable amount of Cr content is favorable for the formation of the oxide scale Cr2O3 and the quality assurance at the initial stage of oxidation, which is able to slow down the oxidation rate. The quality of the oxide scale CrWO4 is better than that of Cr2WO6, indicating that the formation of the oxide scale CrWO4 is beneficial to weaken the further oxidation of the W-20Cr alloy.