Boronizing and Characterization of Fe-Co Binary Alloys Produced in Controlled Atmosphere

This study was carried out to reveal the effect of amount of co in the substrate on boronising behavior of fe-co alloy. firstly, binary fe-co alloys (at. % 1, 2, 4, 8, 12, 16 co) were prepared under argon/vacuum atmosphere. the fe-co alloys along with pure fe were borided with pack boronizing method at 1100˚c for 3 hours. microstructure, phase composition, hardness with thickness, chemical composition and surface morphology of boride layer were characterized by using x-ray diffraction, sem-eds, hardness measurement device and profilometer. the formation of tooth shaped boride layer on all substrates were observed. the typical saw tooth morphology and the boride layer thickness formed on pure fe were not changed with co addition into the substrates. it was revealed that the boride layer contained feb and fe2b phases, and the phase content was not changed with co concentration in the substrates. the existence and homogenous distribution of co in the boride layer were revealed. the hardness (1450 hv - 2200 hv) of the boride layer was found to be in the same range of hardness of boride layer formed on pure iron and was independent from the boride layer thickness.