Production of Fe-C Powders with Improved Structure

Production of Fe-C alloy powders by mechanical alloying was studied. Fe and graphite elemental powder mixtures containing ۰.۸ and ۱.۵wt.% graphite were mechanically alloyed using a planetary ball mill. The structural changes of powder particles during mechanical alloying were studied by x-ray diffractometery, scanning electron microscopy and microhardness measurements. For both compositions, mechanical alloying for ۳۰h resulted in the development of a nanocrystalline structure with a typical grain size of ۱۶nm containing nanoscale size Fe۳C phase. This structure exhibited high microhardness value of the order of ۶۰۰Hv. The powder particles after ۳۰h of milling had a nearly spherical morphology and narrow size distribution. The mean powder particle size for Fe-۰.۸wt.% graphite composition was ۱۵μm, whereas the Fe-۱.۵wt.% graphite composition achieved a smaller particle size with a mean of ۹μm due to higher graphite content.

Keywords:

Powder preparation , Fe-C , Mechanical alloying , Nanomaterials