Effect of anneal on magnetic properties and structural state of iron powders ground in carbon-rich medium

Intense milling of iron powders in a carbon-rich liquid leads to carbonizat ion of powder particles to concentrations of up to several weight percents, alongside the notable reduction in the dimensions of mosaic blocks and for mation of a nanocrystalline structure, which results in a lower coercive fo rce of the powder. X-ray and Mossbauer data indicate that Fe-C disordered solid solutions are formed in the regions of mosaic-block boundaries in the process of the powd er milling. The anneal forms the Fe3C ordered carbide phase from the disord ered solid solution, which raises the coercive force in the powders beyond 100 A/cm.