Structure and magnetic properties of mechanically alloyed (Fe70Co30)91Cu9 powder

(Fe70Co30)91Cu9 alloy is prepared by mechanical alloying of pure Cu, Fe, Co powder using a high energy ball mill, with increasing milling time ranging from 4 up to 45 h. The variation of the morphology and the elemental distribution were investigated at these different stages on various grains of the alloy using a scanning electron microscope with a dispersive energy analyzer. Microstructural changes during the mechanical alloying have been studied by X-ray diffractometry (XRD). Some magnetic properties at room temperature were measured by a vibration sample magnetometer. According to the present experiments, a body-centered cubic nanostructured Fe–Co alloy were developed with an average crystallite size of about 13 nm by milling for 32 h. With increasing the milling time, the crystallite size decreased for all powders. Increase in microstrain is observed with increasing the milling time. The magnetic measurements show a contrasting saturation magnetization and coercivity (Hc) in Fe–Co alloys. These variations are explained on the basis of crystallite size and strain variations in the samples during milling.

► The Fe70–Co30 alloys are well known in having very high saturation magnetization.
► It has shown that Cu has a great effect in reducing the required milling time to accomplish solid solution process.
► Adding Cu to the alloy has led to crystallite size refinement and therefore has improved the magnetic properties.