Deoxidation and densification mechanisms in a pre-sintered Fe-WC-Mo2C-Cr3C2-VC-C alloy

Abstract

Pre-sintered Fe-WC-Mo2C-Cr3C2-VC-C alloy were prepared by using carbide powder and iron powder. After preoxidizing the powder and deoxidation, the apparent density of a Fe-WC-Mo2C-Cr3C2-VC-C alloy and the evolution of internal pores in its structure were determined during the exhaust process. The results show that the gas produced by deoxidation significantly affected the densification process, the pre-sintered sample exhibit expansion and then shrinkage. After holding at 1040°C, the volume of sample is 1.75% larger than that of the green compact with the lowest density. After sintering at 1220°C, the volume decreased by 15.27%. The reaction gas gradually moves from the inside to the outside of the sample, and the direction of densification extend from the center of the sample to its edges. After carbothermal reaction, the oxygen content is reduced from 0.35 wt.%–1.05 wt.% to below 10 ppm. The amount of oxygen removed is positively and linearly correlate with the amount of carbon consumed.

Keywords

• Iron-based alloys
• Carbides
• Carbothermal reaction
• Deoxidation
• Densification