Abstract
Since Fe4N decomposes at 670°C, sintering of Fe4N powder has not been performed under atmospheric pressure. In this study, Fe4N powders have been sintered below the decomposition temperature applying hipping pressure. The sealed capsule containing Fe4N powder was hipped at 450-550°C for 2 hours under 50-200 MPa. The decomposition of Fe4N was confirmed at 550°C. Therefore, hipping temperature was restricted below 500°C. The maximum relative density 97% was obtained for the specimen hipped at 500°C under the maximum pressure of 200MPa. The specimen obtained at 450°C has a higher saturation magnetization than that obtained at 500°C. The maximum saturation magne-tization 182emu/g was measured for a specimen obtained at 450°C under 200 MPa. The saturation magnetization was decreased to 151 emu/g by the addition of small amount of oxygen (0.33wt%) to Fe4N raw powder. In addition, the corrosion resistance of the hipped Fe4N was higher than that of steel.
