The effect of Ni and Ti additions on the glass forming ability and magnetic properties of Al-Fe-Y alloy prepared by mechanical alloying

Amorphous Al ₈₂Fe ₁₄Ni ₂Y ₂ and Al ₈₂Fe ₁₄Ti ₂Y ₂ alloys were synthesized by mechanical alloying. Morphological and structural characterizations of the powders, milled for different periods of time, were investigated by scanning electron microscopy and X-ray diffraction methods. The dissolution of Ni and Al into the Fe lattice led to the formation of Fe(Ni,Al) solid solutions in Al ₈₂Fe ₁₄Ni ₂Y ₂ alloy after 20 h of milling. A slower dissolution of Ti and Al into the Fe lattice can be observed for Al ₈₂Fe ₁₄Ti ₂Y ₂ after milling 40 h. The fully amorphous structure can be obtained for Al ₈₂Fe ₁₄Ni ₂Y ₂ after 60 h of milling. The amorphization of the Al ₈₂Fe14Ti ₂Y ₂ sample milled for 100 h was not complete, and a partially nanocrystal phase of Ti was still present. Coercivity (Hc) and the saturation magnetization (Ms) of as-milled powders decreased markedly with increasing milling time. The magnetic properties of the alloys were consistent with the structural changing during milling process. The amorphous phase transforms into fcc-Al and metallic compounds after annealed DSC treatment.