THE X-RAY DIFFRACTION ANALYSES ON THE MECHANICAL ALLOYING OF THE Mg2Ni FORMATION

THE X-RAY DIFFRACTION ANALYSES ON THE MECHANICAL ALLOYING OF THE Mg2Ni FORMATION. The synthesis and characterization of Mg2Ni compound by using mechanical alloying technique have been performed. The material is milled under the varied milling time of 20, 25, 30, 35 and 40 hours. The result of measurements by using X-ray diffractometer showed that the refinement results on X-ray diffraction pattern appear to be very good fitting between calculation and observation. It is shown that the specimens consist of three phases, namely Mg2Ni, MgO and MgNi2. For milling time between 20 hours to 25 hours, the mass fraction of the Mg2Ni phase increases from 42.19% to 51.03%. Continuous milling of the specimen up to 40 hours will reduce the Mg2Ni mass fraction to 11.86%, probably due to the presence of oxygen, and consequently will increase the mass fraction of MgNi2 compound. It is concluded that the milling time will influence the formation of Mg2Ni phase. At this research, 25 hours milling time is the best time to obtain the highest formation of Mg2Ni compound. Microstructure analyses of the specimens indicate that milling time of 30 hours is the minimum time required to reduce the particle sizes of the Mg-Ni mixed specimen from 3,5 ~10 tm into nanosize particles. It starts to agglomerate after 40 hours of milling due to the growth of magnetic properties of the powders and the change of crystal orientations into amorphous state.