| An investigation was carried out on the possibility whether metal powder injection moulding using sieve size powders instead of ultrafine carbonyl powders could be applied to the fabrication of high performance Ni-Mo-steel sintered parts. The debinding was performed by employing two step debinding process. The higher the green density and the shorter the presintering time, the higher sintered density of the injection moulded parts could be obtained in Fe-5Ni-3Mo-0.2B-0.4P alloy steel. The injection moulded parts with the relative sintered density above 97% could be obtained by following three step process; debinding, presintering at 650℃ for Omin, sintering at 1230℃ for 1h. The hardness and UTS of the sintered MIM part at 1230℃ for 1 and 3h were 40HRc, 272±19MPa and 44HRc, 458±9MPa, respectively. |
|
