Preparation of Fe4N Sintered Compact by HIP

Fe4N powder, which is known as a softmagnetic material, was sintered by Hot Isostatic Pressing (HIP). The powder was obtained by heating a carbonyl iron powder at 500°C for 4h in the mixture of H2-NH3(60vol%). Then, the Fe4N powder was encapsulated into an Al tube in troidal shape. Hipping was performed below 500°C to prevent the decomposition of Fe4N. Single phase Fe4N compact with 99% relative density was obtained under the condition of 450°C, 200MPa and 120min. The saturation magnetization of the compact was 150emu/g.