Isothermal section of the Al–Dy–Zr ternary system at 773 K

The phase relations in the Al–Dy–Zr ternary system at 773 K have been investigated by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) with energy disperse X-ray spectroscopy (EDX) in backscattered electron imaging (BSE) modes. The isothermal section at this temperature is featured with 17 single-phase regions, 32 two-phase regions and 16 three-phase regions. Besides, the ternary compound Al30Dy7Zr3 has been confirmed to be existed. The maximum solid solubility of Zr in AlDy2, Al2Dy3, AlDy, Al2Dy and Al3Dy at 773 K is determined to be 11.5 at.%, 7.8 at.%, 2.4 at.%, 22.5 at.% and 2.5 at.%, respectively.

► The phase relations in the Al–Dy–Zr ternary system at 773 K were firstly investigated by powder X-ray diffraction, scanning electron microscopy and Energy Disperse Spectroscopy techniques. The 773 K isothermal section of this ternary system consists of 17 single-phase regions, 32 two-phase regions and 16 three-phase regions.
► The existence of one ternary compound Al30Dy7Zr3 was confirmed.
► By the phase-disappearing method and comparing the shift of the XRD pattern of the samples near to the compositions of the binary phases, the solid solubility ranges of all the single phases have been determined. Nine solid solution regions were observed in this system. The maximum solid solubility of Zr in AlDy2, Al2Dy3, AlDy, Al2Dy and Al3Dy is found to be 11.5 at.%, 7.8 at.%, 2.4 at.%, 22.5 at.% and 2.5 at.%, respectively, at 773 K.