Composite powder and compacts of iron/iron oxide type produced by mechanosynthesis and reactive sintering

摘要

Composite powder of Fe/Fe_20_3 type was synthesized by mechanical milling using commercially Fe and Fe_20_3 powders in mass ratio of 35/65. The milling process leads to the powder homogenization, powder activation and formation of some Fe/Fe_20_3 composite particles. The Fe/Fe_20_3 composite powder obtained by mechanical milling and the un-milled Fe/Fe_20_3 mixture were subjected to the reactive sintering procedure in argon atmosphere at 1100 °C for 6 hours. The sintering procedure promotes the reaction of the Fe with the Fe_20_3 and the result is a sintered composite compact of Fe/Fe_3O_4/FeO type. The microstructure of the Fe/Fe_30_4/Fe0 sintered composite compacts presents iron clusters in an oxide matrix. A more homogeneous iron clusters size and distribution in oxide matrix is observed in the case of the sintered compact obtained from mechano-activated powder. The X-ray diffraction (XRD), laser particles size analysis (LPSA), optical (OM) and scanning electron (SEM) microscopies techniques were used for the investigations.