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 carbonization of powder particles to concentrations of up to several weight percents, alongside the notable reduction in the dimensions of mosaic blocks and formation of a nanocrystalline structure, which results in a lower coercive force of the powder. X-ray and Mössbauer data indicate that Fe?C disordered solid solutions are formed in the regions of mosaic-block boundaries in the process of the powder milling. The anneal forms the Fe₃C ordered carbide phase from the disordered solid solution, which raises the coercive force in the powders beyond 100 A/cm.