| Summary: | 碩士 === 國立高雄應用科技大學 === 模具工程系碩士班 === 102 === The objectives of this study are investigated the effect of addition a third element Ni(4, 6 at.%) and V(9 at.%) into the bulk Fe-Ga ferromagnetic shape memory alloys (FSMA), in which the nickel (Ni) and Vanadium (V) elements substitute for parts of iron (Fe). The microstructures and magnetic properties of the Fe77Ga19Ni4 and Fe73Ga18V9 FSM alloys solution-treated (ST) at 1100℃ for various times quenched in ice brine and parts of samples post ST then aged at 450℃-750℃ for 24h furnace cooled (FC), were investigated by Vickers hardness (Hv), x-ray diffraction (XRD), optical microscope (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) , Model P3 strain indicator and recorder, and superconducting quantum interference device magnetometer (SQUID).
The research results indicate that adding Ni and V to the Fe-Ga FSMAs enhanced the formation of B2+D03 structures, which drastically decreased the saturation magnetostriction of the Fe77Ga19Ni4 and Fe73Ga18V9 FSMAs. When both alloys were ST and aged at 750℃ for 24h furnace cooled (FC), furthy decreased the saturation magnetostriction and destroyed the ferromagnetic shape memory effect (FSME) in aged Fe77Ga19Ni4 and Fe73Ga18V9 FSMAs .
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