Effect of Carbon on the Physical and Structural Properties of Boride Fe₂B

<p>For Fe-В and Fe-В-С system alloys one of the structure constituent is iron boride Fe&lt;sub&gt;2&lt;/sub&gt;B but in the literature there is no information on carbon solubility limit in iron boride Fe2В. The object of this paper is to reveal the effect of carbon on the physical and structural properties of boride Fe&lt;sub&gt;2&lt;/sub&gt;B. Investigation was performed for the specimens with carbon content of 0,05 - 0,80 % (wt.) and boron content of 9,0 - 15,0 % (wt.), the rest is iron. To determine the physical properties of alloys we use microstructure analysis, X-ray microanalysis and X-ray structural analysis. It is found that carbon doping of boride Fe&lt;sub&gt;2&lt;/sub&gt;Bleads to a feeble lattice strain and effects on the physical characteristics of boride. We estimate the free energy of boride Fe&lt;sub&gt;2&lt;/sub&gt;B and carbon content in Fe&lt;sub&gt;2&lt;/sub&gt;Bphase. Carbon can substitute up to 3 – 8 % of boron atoms in Fe2B phase depending on the temperature which is verified by experimental data. The carbon solubility in this phase is also examined.</p><p>Keywords: iron boride Fe&lt;sub&gt;2&lt;/sub&gt;B, Fe-В alloys, free energy of the phase, carbon solubility.</p>