The microstructures of Zr-Cr binary alloys based upon the Cr2Zr Laves phase were characterized by using optical and scanning electron microscopy, electron probe analysis, X-ray diffraction, transmission electron microscopy and density measurements. Eutectic compositions which corresponded to the reactions: liquid → Cr solid solution + Cr2Zr and liquid → Zr solid solution + Cr2Zr occurred at about 20.5 and 72at%Zr, respectively. The Cr2Zr Laves phase had a solid-solution range of 31 to 34at%Zr, which was more extended on the Cr-rich side of stoichiometry. The alloy stoichiometry and heat treatment affected the phase stability and microstructure of the Cr2Zr Laves phase. Atomic defect structures, introduced into the Cr-rich and Zr-rich sides of stoichiometry were of antisite type and a mixture of antisite type and vacancy-type, respectively. The observed defect structures were explained in terms of atomic size factors.

Microstructures and Defect Structures in ZrCr2 Laves Phase Based Intermetallic Compounds. S.Kanazawa, Y.Kaneno, H.Inoue, W.Y.Kim, T.Takasugi: Intermetallics, 2002, 10[8], 783-92