Ternary Phase Regions Research Articles

Phase Equilibria in the Al-Zr-Nd System at 773 K

The isothermal section of the phase diagram of the Al-Zr-Nd ternary system at 773 K has been investigated by means of x-ray powder diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM) for the first time. The existences of 14 binary compounds i.e. Al3Zr, Al2Zr, Al3Zr2, AlZr, Al3Zr4, Al2Zr3, AlZr2, AlZr3, α-Al11Nd3, Al3Nd, Al2Nd, AlNd, AlNd2 and AlNd3 were confirmed. The isothermal section consists of 17 single-phase regions, 31 binary-phase regions and 15 ternary-phase regions. No binary compound is found in the Nd-Zr binary system. No ternary compound is found in the present work. None of the phases in this system reveals a remarkable solid solution at 773 K.

Interactions of the components in the Al–V–Nd system at 773 K

The phase equilibria of the Al–V–Nd ternary system at 773 K were investigated for the first time, mainly by means of X-ray powder diffraction (XRD), scanning electron microscope (SEM) and energy dispersive analysis (EDX). The existence of 11 binary compounds, i.e. Al 21V 2, Al 45V 7, Al 23V 4, Al 3V, Al 8V 5, Al 11Nd 3, Al 3Nd, Al 2Nd, AlNd, AlNd 2 and AlNd 3 were confirmed. At 773 K, one ternary-phase Nd 6V 4Al 43 was confirmed and it was indicated that this compound has a hexagonal structure with space group P6 3/mcm (no. 193) and the lattice parameters of a = 1.1028 nm, c = 1.7931 nm, c/ a = 1.626 and V = 1.893 nm 3. The isothermal section of the Al–V–Nd ternary system consists of 15 single-phase regions, 28 binary-phase regions and 14 ternary-phase regions. The solid solubility of Al in V is up to 39 at.% Al at 773 K.

Experimental study of the 773 K isothermal section in the Ce–Ti–Si ternary system

The isothermal section at 773 K of the Ce–Ti–Si ternary system has been investigated by means of X-ray powder diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscope–energy dispersive X-ray spectroscopy (SEM–EDX). The existences of 11 binary compounds, namely Ce 5Si 3, Ce 3Si 2, Ce 5Si 4, CeSi, Ce 3Si 5, CeSi 2, Ti 3Si, Ti 5Si 3, Ti 5Si 4, TiSi and TiSi 2 have been confirmed. No ternary compound was found in this work. The results show that the phase equilibria consists of 14 single-phase regions, 25 binary phase regions and 12 ternary phase regions. The existence of the binary compound Ce 5Si 3 with the Cr 5B 3-type crystal structure (space group: I4/mcm, a = 0.7890, c = 1.373) was experimentally confirmed.

The phase relations in the Ce–Sn–Ti ternary system at 473 K

The phase equilibria of the Ce–Sn–Ti system at 473 K have been investigated by means of X-ray powder diffraction (XRD). The existence of 13 binary compounds, i.e. Ce 3Sn, α-Ce 5Sn 3, Ce 5Sn 4, Ce 11Sn 10, Ce 3Sn 5, Ce 3Sn 7, Ce 2Sn 5, CeSn 3, Ti 2Sn 3, Ti 6Sn 5, Ti 5Sn 3, Ti 2Sn and Ti 3Sn were confirmed. The isothermal section consists of 16 single phase regions, 29 binary phase regions and 14 ternary phase regions. No ternary compound is found in the ternary system. None of the phases in this system reveals a remarkable homogeneity range at 473 K.

Phase equilibria in the Al–Zr–Ce system at 773K

Abstract The phase equilibria of the Al–Zr–Ce system at 773 K have been investigated by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), optical microscopy (OM) and differential thermal analysis (DTA). The existences of 13 binary compounds, i.e. Al 3 Zr, Al 2 Zr, Al 3 Zr 2 , AlZr, Al 3 Zr 4 , Al 2 Zr 3 , AlZr 2 , AlZr 3 , α-Al 11 Ce 3 , Al 3 Ce, Al 2 Ce, β-AlCe 3 and AlCe were confirmed. The isothermal section consists of 16 single-phase regions, 29 binary-phase regions and 14 ternary-phase regions. No ternary compound is found in the present work. None of the phases in this system reveals a remarkable homogeneity range at 773 K.

The phase equilibria in the Ti–Cu–Y ternary system at 773 K

Physical–chemical analysis apparatuses, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA) were employed in constructing the isothermal section of the Ti–Cu–Y system at 773 K. The existences of 10 binary compounds, Ti 2Cu, TiCu, Ti 3Cu 4, Ti 2Cu 3, TiCu 4, Cu 6Y, Cu 4Y, Cu 7Y 2, Cu 2Y and CuY were confirmed. The isothermal section consists of 13 single-phase regions, 23 binary phase regions and 11 ternary phase regions. No ternary compound is found in this work. Except the binary compounds YCu 6 and TiCu 4 show homogeneity regions less than 1.5 at.%, none of the other phases in this system reveals a remarkable homogeneity range at 773 K.

Phase equilibria of the Co–Ta–Ti system at 950 °C

The phase equilibria of the Co–Ta–Ti system at 950 °C were investigated via a combination of diffusion couples and equilibrated alloys. The samples were examined by means of optical microscopy, X-ray diffraction, scanning electron microscopy, and electron probe microanalysis. The experimental results showed the existence of no ternary compounds at 950 °C. Two continuous series of solid solutions form between γ-TaCo 2 and TiCo 2 (h), and between β-TaCo 2 and TiCo 2 (c), respectively. The 950 °C isothermal section consists of 10 single-phase regions, 15 binary phase regions and 6 ternary phase regions. The following six three-phase equilibria at 950 °C were well determined: (1) (Co) + TiCo 3 + Ta 2Co 7, (2) TiCo 3 + Ta 2Co 7 + (Ta,Ti)Co 2 (h), (3) (Ta,Ti)Co 2 (c) + TiCo + TaCo, (4) TiCo + TaCo + Ta 2Co, (5) TiCo + Ta 2Co + (Ta,Ti) and (6) TiCo + Ti 2Co + (Ta,Ti).

Isothermal section of the Ti–Zr–Sn ternary system at 473 K

Ti–Zr–Sn alloys were obtained by melting pure elements in an arc furnace. Mainly by the method of X-ray diffraction (XRD), the character of phase equilibrium at 473 K is studied for the Ti–Zr–Sn system. The isothermal section at 473 K consists of 11 single phase regions, 16 binary phase regions and 6 ternary phase regions. The existence of a binary compound Ti 2Sn 3 was confirmed in the isothermal section. Zr 5Sn 4 was not observed and no ternary compound is found in the ternary system. The solubility of Zr in Ti 3Sn is up to 5 at.% Zr. The solubility of Ti in ZrSn 2 is about 4 at.% Ti. There is continuous solid solubility between Ti 5Sn 3 and Zr 5Sn 3.

The 773 K isothermal section of the Ti–Co–V ternary system

The isothermal section of the Ti–Co–V ternary system at 773 K have been investigated mainly by powder X-ray diffraction (XRD) and differential thermal analysis (DTA). It consists of 11 single-phase regions, 19 binary-phase regions and 9 ternary-phase regions. There are eight binary compounds, i.e. VCo 3, VCo, V 3Co, h-TiCo 2, c-TiCo 2, TiCo, Ti 2Co and TiCo 3 in the Ti–Co–V system. Co, VCo 3, VCo, and TiCo have a range of homogeneity. The solubilities of Ti in VCo 3, VCo and V 3Co were determined to be up to 19.7 at.%, 4.1 at.% and 7.6 at.% Ti, respectively, the solubilities of V in TiCo and Co were about 23.6 at.% and 6 at.% V.

Phase equilibria of the Zr–Ti–Si ternary system at 773 K

The phase equilibria of the Zr–Ti–Si ternary system at 773 K have been investigated mainly by powder X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive analysis (EDX). The isothermal section consists of 14 single-phase regions, 23 binary-phase regions and 13 ternary-phase regions. The binary compounds Zr 3Si and Zr 5Si 3 are not observed at 773 K. Therefore, there are 10 binary compounds, i.e. Zr 2Si, Zr 3Si 2, Zr 5Si 4, ZrSi, ZrSi 2, Ti 3Si, Ti 5Si 3, Ti 5Si 4, TiSi and TiSi 2 in the Zr–Ti–Si system at 773 K. Ternary compound Si 3Ti 2Zr 3 is found at this isothermal section. The solubilities of Zr in TiSi 2, TiSi, Ti 5Si 4, Ti 5Si 3 and Ti 3Si were determined to be up to 10, 11, 12, 13 and 7 at.% Zr, respectively; the solubilities of Ti in Zr 3Si 2, Zr 5Si 4, ZrSi and ZrSi 2 were about 5.4, 14, 7 and 14 at.% Ti.

The phase equilibria of the La-Ti-Si ternary system at 773 K

Abstract The phase equilibria of the Zr–Ti–Si ternary system at 773 K have been investigated mainly by powder X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive analysis (EDX). The isothermal section consists of 14 single-phase regions, 23 binary-phase regions and 13 ternary-phase regions. The binary compounds Zr3Si and Zr5Si3 are not observed at 773 K. Therefore, there are 10 binary compounds, i.e. Zr2Si, Zr3Si2, Zr5Si4, ZrSi, ZrSi2, Ti3Si, Ti5Si3, Ti5Si4, TiSi and TiSi2 in the Zr–Ti–Si system at 773 K. Ternary compound Si3Ti2Zr3 is found at this isothermal section. The solubilities of Zr in TiSi2, TiSi, Ti5Si4, Ti5Si3 and Ti3Si were determined to be up to 10, 11, 12, 13 and 7 at.% Zr, respectively; the solubilities of Ti in Zr3Si2, Zr5Si4, ZrSi and ZrSi2 were about 5.4, 14, 7 and 14 at.% Ti.

Phase equilibria in the Y–Ti–Si system at 773 K

Abstract Physico-chemical analysis techniques, including X-ray powder diffraction, scanning electron microscopy, optical microscopy and differential thermal analysis were employed in constructing the isothermal section of the Y – Ti – Si system at 773 K. The isothermal section consists of 12 single phase regions, 21 binary phase regions and 10 ternary phase regions. No ternary compound is found in the work. None of the phases in this system reveals a remarkable homogeneity range at 773 K.

Phase relations in the Cu–La–Sb system at 693 K

The phase relation of the Cu–La–Sb ternary system at 693 K has been investigated mainly by means of X-ray powder diffraction with the aid of optical microscopy and differential thermal analysis. This section consists of 17 single phase regions, 33 binary phase regions and 17 ternary phase regions. Two ternary compounds CuLaSb 2 and Cu 3La 3Sb 4 were confirmed.

Phase relations in the BaO–B 2O 3–TiO 2 system and the crystal structure of BaTi(BO 3) 2

In this paper, the subsolidus phase relations in the ternary system BaO–B 2O 3–TiO 2 have been investigated. The phase diagram consists of 15 ternary phase regions. There exist 11 binary compounds and two ternary compounds. The ternary compound, BaTi(BO 3) 2, is isostructural with CaMg(CO 3) 2. It crystallizes in a rhombohedral system with the space group R-3. The lattice parameters are a=5.0205(2) and c=16.3844(1) Å. Final refinement on the diffraction data converge to R p=9.09, R wp=12.24, and R exp=3.75%.

Phase relations in the MgO–Ga 2O 3–B 2O 3 system and the crystal structure of MgGaBO 4

In this paper, the subsolidus phase relations of the ternary system MgO–Ga 2O 3–B 2O 3 were investigated. There are five binary compounds and one ternary compound. The ternary phase diagram consists of eight ternary phase regions. The ternary compound, GaMgBO 4, is isostructural to Y 2BeO 4. It crystallizes in the orthorhombic system with the space group Pnam and lattice parameters a=9.1847(1) Å, b=9.2942(1) Å, c=3.0779(1) Å, Z=4 and ρ cal.=4.267 g/cm 3. The Mg 2+ and Ga 3+ ions are distributed between the two cation sites: 77.8% Ga 3+ and 22.2% Mg 2+ occupy the cation site I, others (22.2% Ga 3+ and 77.8% Mg 2+) occupy the cation site II. In this structure the Mg 2+ and Ga 3+ ions are surrounded octahedrally by oxygen atoms, the borate ion is a single triangle (BO 3). The most important feature of this structure is the way these octahedra are linked together by sharing edges to form ribbons, which are one octahedron thick and four octahedra wide in the ab plane and extend infinitely along the direction of the c axis. The XRD results show no phase transition occurs between −173°C and 227°C. The lattice parameters and the volume expansion coefficient were calculated.

Phase compositions and microstructural characteristics of solidified Al 2O 3-rich spinel solid solution/YAG composite

The phase compositions and microstructures of an Al 2O 3-rich spinel solid solution (MA ss)–YAG composite were investigated by conventional solidification. A binary eutectic system of YAG–MA ss exhibiting changed eutectic temperature was proven to exist in the YAG–spinel–alumina ternary phase region. A YAG–MA ss eutectic-like composite was obtained by controlled cooling process. It was found that metastable phase, YAlO 3, was formed during rapid solidification of the YAG–MA ss composite from an annealing temperature of 1795°C. When reheating the as-solidified YAlO 3–MA ss composite at 1500°C, a YAG–MA ss composite with fine-grained YAG phase was obtained.

Structure and mechanical properties of amorphous Ti–B–N coatings

In this investigation Ti–B–N-coatings were prepared on high speed steel and silicon substrates by reactive magnetron sputtering from a TiB2 target with a stepwise increase of the nitrogen flow rate. Some samples were vacuum-annealed up to 600°C.All Ti–B–N layers had a dense structureless morphology, whereas the pure TiB2 coating was crystalline and had a strong [001] fibre texture. The composition of the films was characterized by a nearly constant B/Ti ratio of 2.6 and a variable N/Ti ratio from 0 to 6.3. Consequently, the samples were situated in two different ternary phase regions. With the increasing nitrogen flow rate the measured compressive residual stresses and the hardness of the Ti–B–N coatings decreased up to 50% in comparison with the TiB2, whereas the critical load of the adhesive failure was not influenced.It could be detected that the amorphous state and the chemical composition were stable during annealing up to 600°C. The compressive residual stresses had been reduced by thermally activated relaxation processes. The TiB2 coatings got tensile stresses, whereas in the Ti–B–N films the compressive stresses were still present. Probably, ordering occurs in the amorphous coatings, because their hardness increases by up to 40%. The results of scratch tests were not influenced by annealing.

A study of structural and thermodynamic properties of the YNi5−xAlx–hydrogen system

Alloys of the composition YNi5−xAlx were prepared and studied by means of X-ray powder diffraction. It was found that the hexagonal symmetry of YNi5 (space group P6/mmm; CaCu5 type) is retained up to the composition YNi3Al2. However, beyond this composition and up to YNi2Al3 there also exists a ternary single phase region, but with a hexagonal structure of the YCo3Ga2 type (space group P6/mmm). It was found that all ternary alloys having the CaCu5 structure react readily with hydrogen and absorb between 1.85 and 3.96 hydrogen atoms per alloy formula unit at room temperature. Binary YNi5 as well as the remaining ternary alloys do not exhibit any significant absorption of hydrogen up to 673 K and 15 MPa of hydrogen. At room temperature the hydrogen capacity and the equilibrium pressure decrease with increasing content of aluminium. The entropy and the enthalpy have been extracted for the systems that exhibit an equilibrium pressure plateau.

The effect of aluminium on the structural and hydrogen sorption properties of ErNi5

The substitution of aluminium for nickel and its effect on the structural and hydrogen sorption properties of the binary ErNi5 has been studied. It was determined that nickel can be replaced by aluminium up to the composition ErNi3Al2 without changing the prototype crystal structure of the CaCu5 type (space group P6/mmm). However, beyond this composition and up to ErNi2Al3 there also exists a ternary single phase region, with a structure of the YCo3Ga2 type, but closely related to the CaCu5 structure. It was found that all ternary alloys having the CaCu5 structure absorb between 1.96 and 2.95 hydrogen atoms per formula unit at room temperature. The binary ErNi5 as well as the remaining ternary alloys do not exhibit any significant hydrogen uptake. The structural and hydrogen sorption properties of the ErNi5−xAlx system are compared with some other related systems and briefly discussed. Generally, in these systems the hydrogen capacity and the equilibrium pressure decrease with increased content of aluminium. In the case of ErNi5−xAlx it was found that the hydrogen capacity increases and the equilibrium pressure decreases as the concentration of aluminium increases.

Phase Relations of the Nd 2O 3-Pr 6O 11-CuO Ternary System

The subsolidus phase relations of the Nd 2O 3-Pr 6O 11-CuO ternary system sintered in air at 950°C have been investigated by X-ray powder diffraction. The system can be divided into one ternary phase region and three binary phase regions. The solid solution Nd 2- x Pr x CuO 4-δ has been observed to exist over the composition region 0 < x > 2. The solid solution has a tetragonal structure, and its lattice parameters increase linearly with the increasing of the praseodymium content.