Microstructures and magnetic properties of Fe-35%Co alloy fabricated by metal injection molding

摘要

Annular samples are fabricated by metal injection molding using pre-alloyed Fe-35%Co powder. Samples sintered at different temperatures (1275, 1300, 1325, 1350 and 1375 °C) all exhibit a single a-FeCo solid solution phase and have low interstitial impurity contents. They are used as model materials to investigate the influences of microstructures on the magnetic properties. The results show that both sintered density and grain size of the material increase with sintering temperature, which gives the sample sintered at 1375 °C the best magnetic properties The coercivity (H_c) of the sintered samples increases linearly with the grain size, while the initial permeability (μ_i) is inversely proportional to the square root of the coercivity. Based on the above relationships, a mathematic model has been developed which can be used to predict the magnetic properties of the sintered Fe-35%Co alloy from its microstructures.