Effect of Sintering Temperature on the Microstrutcure and Magnetic Properties of Fe-6.5%Si Alloy Fabricated by Metal Injection Molding

The present work demonstrated the influence of sintering temperature on the microstructure and magnetic properties of Fe-6.5%Si alloys fabricated via metal injection molding. The samples were sintered in an Ar atmosphere at three different temperatures, 1100, 1200, and 1300℃. Microstructural observations of the sintered sample revealed that, with increasing sintering temperature, the average grain size of the ferrite phase increased, while the fraction of the micro pore decreased. These results were attributed to the increasing mobility of the grain boundaries. The hysteresis curves showed that the magnetic properties of the sintered samples as a soft magnet were enhanced with increasing sintering temperature since the saturation magnetization increased and the coercivity decreased, reaching the values of 1.22 tesla and 1.84 kA/m at 1300℃. Moreover, the values of the magnetic hysteresis loss in the sintered samples gradually decreased with increasing sintering temperature due to both the fairly high densification and coarse grain size of the sintered sample.