Experimental investigation of phase relationship in Ti-Fe-Hf ternary system

摘要

Based on diffusion triple and equilibrated alloy methods, phase relations in the Ti-Fe-Hf ternary system were investigated using the experimental data obtained through the combination of optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA) techniques. Isothermal sections of the Ti-Fe-Hf system at both 1073 K and 1273 K were well constructed. There are three and four three-phase regions in these two sections, respectively. According to the present results, Hf can dissolve into FeTi at approximately 3.0% at both 1073 K and 1273 K. A continuous solid solution of Fe-2(Ti, Hf) forms between the binary intermediate compounds Fe2Ti and Fe2Hf (h). Fe2Hf(c) and FeHf2 show large solid solubilities. The solubility of Ti in Fe2Hf(c) changes from 33.9% at 1073 K to 39.0% at 1273 K, while that of FeHf2 can reach up to approximately 63.0% at 1273 K. No ternary compound exists in the Ti-Fe-Hf ternary system.