Amorphization in iron-carbon systems with transition metals by mechanical alloying

Abstract

Mechanical alloying (MA) of elemental powder mixtures of Fe 83− x M x C 17 (M ≡ Cr, Mo or Co) with x = 0–35 was performed using a planetary ball mill, to examine effect of the ternary additions M on amorphization of FeC materials by MA. In the MA processing, the additions Cr and Mo with the high carbide-forming tendency (CFT) in FeC-based systems strongly promoted the amorphization reaction in milled powder products. In contrast, for the case of Co with a lower CFT such a remarkable effect was not observed. These results are interpreted in terms of atomic bonding energies in the ternary FeMC solution and crystal structures of competing stable carbides in the FeMC system. The amorphicity of MA samples was examined by X-ray diffraction, differential scanning calorimetry and electrical resistivity measurements.