2008 年 49 巻 6 号 p. 1480-1485
Nanocrystalline Fe-W composite is synthesized through the reduction of iron oxide/tungsten oxide (Fe2O3/WO3) mixture with pure hydrogen gas at 700–1000°C. AR grade Fe2O3 and WO3 powders were mixed thoroughly in ball mill and compacted. The dried compacts were isothermally reduced in pure hydrogen at 700, 800, 900 and 1000°C. Based on thermogravimetric analysis, the reduction behavior and kinetics reaction mechanism were studied. The initial oxides mixture and the various reduction products were characterized by XRD, SEM, VSM and reflected light microscope to reveal the effect of hydrogen reduction on microstructure, magnetic properties and reaction kinetics of produced Fe-W composite. Complete reduction was achieved with the synthesis of nanocrystalline (36.3 nm) homogenous Fe-W composite. Arrhenius equation with the approved mathematical formulations for the gas solid reaction was applied for the calculation of the activation energy values and detecting the controlling reaction mechanism.
