Fabrication of Lotus-Type Porous Iron by Thermal Decomposition Method
Lotus-type porous iron was fabricated by continuous zone melting technique through thermal decomposition of chromium nitride(Cr1.18N). Nitrogen dissolves into the molten iron through thermal decomposition of Cr1.18N. When the molten iron is solidified in one direction, insoluble nitrogen forms the directional gas pores aligned along the solidification direction. The porosity increases with increasing transfer velocity. For most of lotus metals fabricated by pressurized gas method, the porosity does not change with the transfer velocity owing to constant gas solubility in liquid and solid phase. On the other hand, the porosity of lotus metal fabricated by thermal decomposition method depends on the transfer velocity. This difference is attributed to the decomposition behavior of gas compound dependent upon the heating rate.
Hyungsun Kim, JianFeng Yang, Tohru Sekino, Masakazu Anpo and Soo Wohn Lee
T. Ide et al., "Fabrication of Lotus-Type Porous Iron by Thermal Decomposition Method", Materials Science Forum, Vol. 658, pp. 240-243, 2010