Papers by Author: S.S. Jung

Abstract: The present investigation attempted to optimize the R-D (reduction-diffusion) process for fabricating Sm2Fe17 nanoscale powder from ball-milled powders of samarium oxide and iron oxide using a solid reducing agent of calcium hydrides (CaH2). It was found that the target alloy phase of Sm2Fe17 can be produced by controlling the gas atmosphere in the process of powder preparation to R-D reaction. Powder handling of CaH2 in a protective atmosphere is essential to avoid the formation of Ca(OH)2 which suppresses calcium formation. A switching gas atmosphere of H2 to Ar-H2 during the R-D process at 350oC resulted in a reduction of Fe2O3 and alloying of Sm-Fe, consequently forming nanocrystalline Sm2Fe17.

Abstract: The present investigation has attempted to optimize hydrogen reduction process for the mass production of Fe-8wt%Ni nanoalloy powder from Fe2O3-NiO powder. In-situ hygrometry study was performed to monitor the reduction behavior in real time through measurement of water vapor outflowing rate. It was found that the reduction process can be optimized by taking into account the apparent influence of water vapor trap in the reactor on reduction kinetics which strongly depends on gas flow rate, reactor volume and reduction.