Zhuang Yinghong

Phase relations in the Nd–Al–Si system at 500°C

Abstract The partial isothermal section of the phase diagram of the Nd–Al–Si ternary system at 500°C (50 at.% Nd or less) has been investigated by X-ray diffraction analysis, differential thermal analysis, scanning electron microscopy and electron micro-probe analysis. The existence of six binary compounds, αNd 2 Si 3 , βNdSi x ( x ⩽1.8⩽2.0), NdAl, NdAl 2 , NdAl 3 and αNd 3 Al 11 , and three ternary compounds, NdAl 2 Si 2 ( γ ), NdAl 1.75 Si 0.25 ( δ ), NdAl 1.25 Si 0.25 ( η ), was confirmed. The ternary compound NdAl 1.5 Si 0.5 was not found in this section. This isothermal section consists of 11 single-phase regions, 21 two-phase regions and 11 three-phase regions. The compound NdAl 1.25 Si 0.25 has a large homogeneity range, while the other ternary compounds are non-solubility compounds.

Phase relationships in the Al–Ti–Ho system at 773 K

Abstract The phase relationships in the Al–Ti–Ho ternary system at 773 K have been determined mainly by XRD techniques, with the aid of differential thermal analysis, EPMA, metallography. The existence of 10 binary compounds and two ternary phases, namely TiAl3, TiAl2, TiAl, Ti3Al, Al17Ho2, Al3Ho, Al2Ho, AlHo, Al2Ho3, AlHo3, Al43Ti4Ho6 and Al20Ti2Ho, respectively, have been confirmed. The section consists of 15 single-phase regions, 29 two-phase regions and 15 three-phase regions.

The 520°C isothermal section of the phase diagram of the ternary Dy-Fe-Si system

The 520°C isothermal section of the Dy–Fe–Si system was investigated by X-ray powder diffraction, differential thermal microanalysis and electron-probe microanalysis techniques. At 520°C, it consists of 21 single-phase regions, 46 two-phase regions and 26 three-phase regions. The existence of eleven binary compounds and seven ternary compounds was conformed. Among seven ternary compounds. DyFe3Si6 and DyFe11Si are new phases, which belong to the hexagonal system with a=0.3931 nm, c=1.5431 nm and tetragonal system with a=0.8519 nm, c=0.4780 nm, respectively.

The 500°C isothermal section of the phase diagram of the FeGdNd ternary system

Abstract The isothermal section of the phase diagram of the FeGdNd ternary system at 500 °C has been investigated mainly by X-ray powder diffraction, with aid of differential thermal analysis, scanning electron microscope and electron probe microanalysis. The existence of seven binary compounds, namely Fe 2 Gd, Fe 3 Gd, Fe 23 Gd 6 , Fe 17 Gd 2 , Fe 17 Nd 2 , Fe 17 Nd 5 and δ, was confirmed in this isothermal section. The section consists of 9 single-phase regions, 14 two-phase regions and 6 three-phase regions. The maximum solid solubilities of Fe in α-Nd and Nd in Fe 2 Gd, Fe 3 Gd and Fe 23 Gd are about 0.1 at.%, 2.0 at.%, 1.0 at.%, and 2.0 at.% respectively. No ternary compounds were found in this section.

Isothermal section of the phase diagram of the ternary system Dy–Ni–Ti at 773 K

Abstract The isothermal section of the phase diagram of the ternary system Dy–Ni–Ti at 773 K was investigated by X-ray diffraction, differential thermal analysis, optical microscopy and electron microscopy techniques. It consists of 14 single-phase regions, 25 two-phase regions and 12 three-phase regions. At 773 K, the maximum solid solubilities of Ti in Ni, Dy 2 Ni 17 , DyNi 5 , Dy 2 Ni 7 , DyNi 3 and DyNi 2 are about 7.5 at.% Ti, 5.0 at.% Ti, 3.5 at.% Ti, 2.0 at.% Ti, 3.0 at.% Ti, and 4.0 at.% Ti, respectively. The existence of any ternary compound was not observed. The decomposition of the NiTi compound was not observed under the present conditions.

Phase relation in the Pr–Ti–Al ternary system at 500°C

Abstract The isothermal section of the Pr–Ti–Al ternary phase diagram at 500°C was investigated by powder X-ray diffraction, electron probe microanalysis and differential thermal analysis. The 500°C isothermal section of this ternary system consists of 14 single-phase regions, 26 two-phase regions and 13 three-phase regions. Only one ternary compound Ti 2 Al 20 Pr was proved to exist in this isothermal section. A solid solution of the type Pr(Al 1− x Ti x ) 2 was found in this work. At 500°C, the maximum solid solubility of Ti in Al 2 Pr is 17 at.% Ti and of Pr in Ti 3 Al and TiAl are less than 2 at.% Pr, respectively.

Magnetocaloric Effect of Alloys Gd(Al1 - x Cox)2

Abstract The magnetocaloric effect in alloys Gd(Al 1 - x Co x ) 2 with x = 0, 0.05, and 0.10 were investigated using X-ray diffraction (XRD) and magnetization measurements. It was found that three alloys crystallized in a single phase with MgCu 2 -type structure. The lattice parameter and Curie temperature decreased with increasing Co content, whereas the magnetic-entropy change increased. With a magnetic-field change of 2 T, the maximum of the magnetic-entropy change reached 4.6 J · kg −1 · K −1 near Curie temperature at approximately 95 K in the alloy GdAl 1.8 Co 0.2 , which appeared to be an alternative candidate for active magnetic refrigerants working in the temperature range centered at 100 K.

The isothermal section (500°C) of the phase diagram of the Fe-Ho-V ternary system

Abstract The isothermal section (500°C) of the phase diagram of the Fe–Ho–V ternary system was investigated by X-ray powder diffraction, differential thermal microanalysis, optical microscopy and electron probe microanalysis (EPMA) techniques. The section consists of nine single-phase regions, 16 two-phase regions and eight three-phase regions. Only one ternary compound (Fe 10 HoV 2 ) was found in this isothermal section. The Fe 10 HoV 2 exhibits no homogeneity range. The maximum solid solubility of holmium in α-Fe, δ-FeV and V are about 1.5 at.%, 6 at.%, and 2.0 at.%, respectively.

The ternary system AgCuHo at 500 °C

Abstract The solid state phase equilibria at 500 °C in the AgCuHo (33.3 at.% Ho or less) ternary system were investigated mainly by X-ray powder diffraction, with the aid of differential thermal microanalysis, optical microscopy and electron probe microanalysis. The isothermal section (500 °C) of this system has been established. It consists of six single-phase regions, nine two-phase regions and four three-phase regions. No ternary compound was found in this system, only the binary compounds found in the CuHo and AgHo systems. The maximum solid solubilities of Ag in Cu 5 Ho, Ag in Cu, Cu in Ag 2 Ho, and Cu in Ag are 42, 0.98, 28 and 2.93 at.% respectively. Cu 2 Ho and Ag 3 Ho are non-variable compounds.

Phase equilibria in the ternary HoFeNd system at 500°C

Abstract The solid state phase equilibria and phase relationship in the ternary Ho Fe Nd system at 500°C were investigated mainly by X-ray powder diffraction and by differential thermal microanalysis. The isothermal section at 500°C of this system has been established. The existence of the binary compounds Fe 1 , Nd 2 , in the Fe Nd system and the δ phase (Sm type) in the Ho Nd system were confirmed. The δ phase belongs to the rhombohedral system with a = 0.3636 nm and c = 26146 nm in the hexagonal description. The composition range of the δ phase is from 45 to 65 at.% Nd. The isothermal section consists of nine single-phase regions, 15 two-phase regions and six three-phase regions. The compounds Fe 2 , Nd 2 , and Fe 1 , Ho, form a continuous series of solid solutions. At 500°C. the solid solubilities of Fe in α-Ho, α-Nd or the δ phase are small and Fe 1 , Nd 2 , Fe 3 , Ho 6 , Fe 3 Ho and Fe 3 Ho are non-variable compounds.