Z.F. Gu

Experimental study of ternary Nd–Pt–Fe phase equilibria at 500°C

Abstract The phase equilibria in the ternary Nd–Pt–Fe system at 500°C have been established by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) techniques. Twelve single phase regions (including solid solution regions of the binary compounds) were determined. Twenty-one two phase regions and ten three phase regions were identified to exist at this isothermal section. No Nd3Pt4 phase and new ternary compounds were found.

Experimental determination of the phase relations of the Co–Pt–Dy system at 773 K

The isothermal section of the Co–Pt–Dy system at 773 K was experimentally determined by combining results from X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy investigations. The presence of Co3Dy4 phase at 773 K is confirmed in this study. The four-phase region does not exist at 773 K in the ternary Co–Pt–Dy system, with instead two three-phase regions consisting of Co, DyPt, Dy3Pt4 and Co, DyPt2, Dy3Pt4, respectively. 23 single-phase regions (including solid solution regions of the binary compounds) and 21 three-phase regions were identified to exist at this isothermal section. The highest solid solubility of Dy in α1(Co, Pt), ∊(Co, Pt), α2(Co, Pt), CoPt, CoPt, α(Pt, Co) is less than 1.5 at.% Dy and that of Co in Dy3Pt, Dy2Pt, Dy5Pt3, Dy5Pt4, DyPt, Dy3Pt4, DyPt3, DyPt5 is below 1 at.% Co. The DyPt2 phase dissolves up to about 19 at.% Co. The maximum solid solubility of Pt in Co2Dy, Co3Dy, Co7Dy2, Co17Dy2 is approximately 1 at.% Pt. No new binary and ternary phases were found.