Boriding of equiatomic Fe-Mn binary alloy

Abstract

Synthetic equiatomic Fe-Mn binary alloy was prepared under vacuum-argon controlled atmosphere. Fe-Mn alloy samples were boronized using the commercial Ekabor II powder at 900°C, 1000 °C and 1100 °C for 3 h. The borided samples were characterized by X-ray diffraction, scanning electron microscopy-energy dispersive spec- troscopy, and profilometry. The boride layers were composed of FeB, MnB, MnB2 and Fe2B phases for the samples borided at 1000 °C and 1100 °C while the sample borided at 900°C was composed of only FeB and MnB. The boride layer was well adhered to the substrate with saw-tooth like morphology however some discontinuous band of cracks were observed in the boride layer. The concentration ratio of Fe and Mn were equal along the thickness of the coating though in some areas their ratio interchanged. The boride layer thickness and surface roughness increased with boronizing temperature.