An investigation on the formation of metal-like compounds in the diffusion layer obtained during simultaneous multicomponent saturation of iron (Armco) with boron and zirconium

Abstract

The structure, thickness and microhardness of the diffusion layer obtained during solid phase saturation of iron (Armco) with ZrB 2 using various activators were studied. Monoclinic ZrO 2 and Fe 2B with zirconium doping were established by X-ray phase analysis. The diffusion mobilities of zirconium and boron, together with the increases in their amounts in the layer, were studied by X-ray microprobe analysis, emission spectrography and metallographic analysis. The grain size of the surface layer was established by scanning electron microscopy. The activation energy of the process was calculated. On the basis of thermodynamic calculations, a probable mechanism of formation of metal-like compounds in the diffusion layer in the presence of a given activator is proposed. It was established that during the heat treatment the system became heterogeneous and that transfer of the components took place with the participation of gaseous carriers and a liquid phase.