Comparison of Fe–Ni–P–Si alloys prepared by ball milling

Abstract

Fe–Ni–P–Si alloys were synthesized from powders in a planetary ball-mill. The microstructure and thermal properties of the milled powders were measured by X-ray diffraction, scanning electron microscopy and differential scanning calorimetry. The diffraction peaks of the individual powders are not detected after the first 32 h of milling time. During milling amorphous and amorphous-like phases are formed. Differential scanning calorimetry results show exothermic reactions for all of the compositions indicating a recovery process as well as crystallization of the amorphous phase. The crystallization products are compared to starting powders. The use of Fe and Ni in the alloy reduces both the energy of formation of the amorphous phase and the time necessary to produce this phase.The incorporation of Si into the Fe–Ni-based alloy favors the formation of a more stable amorphous phase. Moreover, the use of Fe 3P as starting powder increases the time to form the amorphous phase. The larger the Si content, the greater the thermal stability of the amorphous phase produced during mechanical alloying.