Investigation of the iron-rich corner of the Fe-Hf-Zr system

The Fe-Hf-Zr phase diagram was determined at 900 °C in the Fe-rich corner by powder x-ray diffraction (XRD) and electron probe microanalysis (EPMA). Iron-rich parts of the Fe-Hf and Fe-Zr binary systems were also reviewed. The existence of Fe23Zr6 with a cubic Mn23Th6 structure was confirmed. A calorimetric study by direct reaction at high temperatures gave the enthalpies of formation of Fe23Zr6, Fe0.70Hf0.30(λ), and some ternary alloys: Fe0.66(Hf, Zr)0.34 and Fey(Hf, Zr)l-y with 76≤y≤100at.%Fe.