The isothermal section of the ZrCrCu ternary system at 580 °C

The 580 °C isothermal section of the ZrCrCu ternary system was determined by means of X-ray diffraction, scanning electron microscopy and electron probe microanalysis. This isothermal section contained 10 single-phase regions, 18 two-phase regions and 9 three-phase regions. No ternary compound was found at 580 °C in the system. The solubility of Cu in the ZrCr2 cubic Laves C15 phase and the solubility of Cr and Cu in the terminal α-Zr solid solution phase were determined. The site occupation of element Cu in the ZrCr2 cubic Laves C15 phase was determined by Rietveld refinement. The Cu prefers to occupy the position of Cr. The CuZr phase, which is not stable at 580 °C in the binary CuZr system, was confirmed to exist at this temperature in the ZrCrCu ternary system. This is probably due to that the dissolving of Cr in the CuZr phase increases its thermodynamic stability.