The 1100 °C isothermal section of the Ti-Co-Si ternary system

The 1100 °C isothermal section of the Ti-Co-Si ternary system has been determined, for which 24 single-phase fields, 42 two-phase fields, and 22 three-phase fields were detected. Ten ternary phases were detected; these include eight previously reported in the literature plus two previously reported, H(Ti₄CoSi₄) and J(Ti₃Co₂Si). The I phase, whose crystallographic data have not been reported before, is found to be orthorhombic with a=0.7961 nm, b=0.7048 nm, and c=0.5467 nm. Except for K and H, all ternary phases show considerable composition ranges, especially the G′ and V phases.     

The 1100 °C isothermal section of the Ti-Co-Si ternary system

The 1100 °C isothermal section of the Ti-Co-Si ternary system has been determined, for which 24 single-phase fields, 42 two-phase fields, and 22 three-phase fields were detected. Ten ternary phases were detected; these include eight previously reported in the literature plus two previously reported, H(Ti₄CoSi₄) and J(Ti₃Co₂Si). The I phase, whose crystallographic data have not been reported before, is found to be orthorhombic with a=0.7961 nm, b=0.7048 nm, and c=0.5467 nm. Except for K and H, all ternary phases show considerable composition ranges, especially the G′ and V phases.     

The isothermal section at 400°C of the Nd–Cu–Sn ternary system

The Nd–Cu–Sn isothermal section at 400°C has been investigated by means of X-ray diffraction, optical and scanning electron microscopy and electron probe microanalysis. The following compounds have been identified or confirmed: NdCu₅Sn, Nd₇Cu₃₅Sn₁₁, NdCu₉Sn₄, NdCuSn, Nd₃Cu₄Sn₄, NdCu₂Sn₂, Nd₂Cu₃Sn₆ and NdCu_1−ySn₂, and their crystal structure have been determined or revised. Single crystal structure determination of the phases Nd₇Cu₃₅Sn₁₁ and Nd₃Cu₄Sn₄ and full profile powder refinement of the compound Nd₂Cu₃Sn₆, previously suggested as Nd₂Cu₄Sn₅, are also given. The subdivision of the composition triangle in tie triangles has been nearly completed. Of the predicted 36 three-phase equilibria, thirty have been defined. The general characteristics of the section have been discussed in comparison with those of other R–Cu–Sn systems formed by light rare earths (R= Ce, Pr).     

Investigation of the nitrogen-nickel-titanium system: The isothermal section at 900 °C

Phase relations in the ternary system N-Ni-Ti have been established experimentally for the 900 °C isothermal section assisted by thermodynamic modeling. Phase equilibria are characterized by an appreciable amount of up to ≅11 at. % N dissolved in the octahedral interstices of the crystal structure of Ti₂Ni. Two-phase equilibria are formed at 900 °C among the pairs Ti₂N + Ti₂NiN_x, TiN_1-x + Ti₂NiN_x, TiN_1-x + TiNi_1-x, and TiN_1-x + Ni(Ti)_x. The investigation is based on X-ray powder diffraction, metallography, scanning electron microscopy, and electron probe microanalysis techniques on about 50 alloys, which were prepared by arc melting or high-frequency levitation melting of appropriate blends of Ti,Ni-powders with TiN used to introduce nitrogen. Key experiments related to the N solubility in the Ti₂Ni phase have been triggered by an interactively performed thermodynamic modeling. The experimental results are in fine agreement with the thermodynamic calculation.     

The isothermal section at 400 °C of the Pr–Ag–Sn ternary system

The phases and equilibria involved in the isothermal section at 400 °C of the Pr–Ag–Sn ternary system have been here investigated after different annealing times by X-ray diffraction, optical and scanning electron microscopy and electron probe microanalysis. Three ternary compounds have been confirmed: PrAgSn hP6 LiGaGe type, Pr₃Ag₄Sn₄ oI22 Gd₃Cu₄Ge₄ type and Pr₅AgSn₃ hP18 Hf₅CuSn₃ type. The solid solubility ranges of the binary compounds have been considered and trends of their lattice parameters studied. The tie-triangles of the ternary system have been defined. The general features of the section are discussed and compared to those of the other R–Ag–Sn ternary systems.     

The isothermal section at 450°C of the Yb–Pr–Mg system

In the framework of a systematic investigation of the ternary alloys formed by magnesium with two different metals of the rare earth family, data obtained in a study of the Yb–Pr–Mg system are presented. In the isothermal section at 450°C, phases have been identified which are based on the ternary extensions of the binary compounds PrMg, PrMg₃, Pr₅Mg₄₁ and YbMg₂. The PrMg₁₂ compound on the contrary shows very small ternary solid solubility. Two ternary compounds have also been identified: τ₁, (Yb_xPr_1-x)Mg₂ (0.15⩽x⩽0.48), cF24–MgCu₂ Laves type and τ₂,≈(Yb_xPr_1-x)Mg_4.5 (0.12⩽x⩽0.40), cF440–GdMg₅ type. The trends of the lattice parameters and the general features of the isothermal section are discussed and compared with those of other magnesium ternary alloys with rare earth elements. The behaviour of the different MeMg₂ Laves phases is particularly highlighted.     

Determination of isothermal section of Fe-Ti-Zr ternary system at 1173 K

Phase relations in the Fe-Ti-Zr ternary system at 1173 K were investigated by means of diffusion-triple approach together with electron probe microanalysis（EPMA） technique. A series of tie lines and tie-triangles were determined and the isothermal section at 1 173 K was established, which consists of four three-phase fields： β（Ti, Zr）＋FeZr2＋FeTi, FeZr2＋FeTi＋Fe2Zr, FeTi ＋Fe2Zr ＋Fe2Ti and Fe2Zr ＋Fe2Ti ＋Fe. The results show that the largest solubility of Ti in Fe2Zr is about 11.3 %（mole fraction） and the solid solubility of Ti in FeZr2 is about 26.9%, the solid solubility of Zr in Fe2Ti is about 8.1% and the solid solubility of Zr in FeTi is 7.2%. The binary compound FeZr2 is nearly a linear compound. No ternary compound is found.     

The isothermal section of the phase diagram of the Dy–Mn–Ni ternary system at 803 K

The isothermal section of the phase diagram of the ternary system Dy–Mn–Ni system at 803 K was investigated by powder X-ray diffraction (XRD), differential thermal analysis (DTA), optical microanalysis and electron probe microanalysis techniques. It consists of 13 single-phase regions, 22 two-phase regions and 10 three-phase regions. At 803 K, the maximum solid solubilities of Mn in Ni, Dy₂Ni₁₇, DyNi₅, Dy₂Ni₇, DyNi₃, DyNi, Dy₃Ni₂ and Dy₃Ni are about 31at.% Mn, 6 at.% Mn, 5.5 at.% Mn, 3 at.% Mn, 5 at% Mn, 5 at.% Mn, 3 at.% Mn and 1.5 at.% Mn, respectively. The maximum solid solubilities of Ni in Mn, DyMn₁₂ and Dy₆Mn₂₃ are about 2.6 at.% Ni, 2 at.% Ni and 4 at.% Ni, respectively. DyMn₂ and DyNi₂ form a continous solid solution in this system. The binary compounds DyNi₄ and Dy₄Ni₁₇ were not observed in this work. The existence of any ternary compound was not observed.     

Yb–Cu–Sn system: the isothermal section at 400°C

Phase equilibria in the ternary system Yb–Cu–Sn have been studied by X-ray powder diffraction analysis, optical and scanning electron microscopy and electron probe microanalysis. The isothermal section has been analysed at 400°C: 10 ternary compounds have been confirmed or determined and the corresponding tie-triangles defined. The ternary compounds are YbCu_4.4Sn_0.6, Yb₃Cu₁₃Cu₄, Yb₁₄Cu₆₀Sn₂₆, YbCu₉Sn₄, Yb₃₀Cu₃₉Sn₃₁, YbCuSn, Yb₅CuSn₃, Yb₂₃Cu₄₂Sn₃₅, Yb₃Cu₄Sn₄, Yb₃₆Cu₁₈Sn₄₆.     

773K isothermal section of Gd—Ni—Ti ternary system

The 773K isothermal section of the Gd-Ni-Ti system was investigated b X-ray diffractometry,optical microanalysis and electron probe microanalysis techniques.The results show that it consists of 13 single-phase regions,23 two-phase regions and 11 three-phase regions.The maximum solid solubility of Ti in Ni,Gd2Ni17,GdNi5 and Gd2Ni7 are 6.0%,3.0%,3.0%,and 2.5(mole fraction).respectively.     

Determination of isothermal sections of Ni-Cr-Nb ternary system

The isothermal sections of Ni-Cr-Nb ternary system at 1 323 K and 1 423 K were determined by means of diffusion triple and energy spectrum analysis (ESA). By analyzing the diffusion layers in the diffusion couples, the compounds forming in this system were identified. There are three similar compounds found at these two temperatures: Ni3 Nb, NiNb and NbCr2-R, and four similar three-phase regions are found : (Ni) (Cr) Ni3 Nb, Ni3Nb NbCr2-R NiNb, NbCr2-R (Cr) Ni3 Nb, NbCr2-R NiNb (Nb). The results show that no phase transformation happens between these tow temperatures. But the solid solubilities of the binary compounds at 1423 K become bigger than those at 1 323 K, especially the solid solubility of NbCr2-R. No ternary compound is observed.     

Determination of isothermal section of Ni—Pt—Ta ternary system at 1173K

The isothermal section of the Ni-Pt-Ta ternary system at 1173K was determined by means of the diffusion triple technology and the electron microprobe analysis.The phase relations in this system were studied.Linear compound(Ni,Pt)3Ta with small solubility forming between Ni3Ta and Pt3Ta was identified.Four binary compounds,i.e.Pt2Ta,Ni2Ta,NiTa and NiTa2,and four three-phase fields,i.e.Pt2Ta (Ta) NiTa2,Pt2Ta NiTa2 NiTa,Pt2Ta (Ni,PT)3Ta NiTa and (Ni,Pt)3Ta NiTa Ni2Ta,were also identified.     

1100℃ isothermal section of Nb-W-Zr-C quaternary system

An isothermal section of the Nb-W-Zr-C system at 1100℃ was established by means of multiphase diffusion couples along with electron microprobe analysis and X-ray diffraction analysis. The isothermal section consists of two single-phase regions, a(Nb, W, Zr) and (W, Nb)2Zr and one double-phase region, a(Nb, W, Zr) (W, Nb)2Zr. It is concluded that (W, Nb)2Zr is an interstitial intermediate phase with the face-centered eubie (Cu2Mg) lattices. The maximum solid solubility of carbon in (W, Nb)2Zr phase is determined as about 4.18%C (mole fraction). The composition ranges of tungsten in the (W, Nb)2Zr phase are 55.41% to 65.98% and the maximum solid solubility of niobium in (W, Nb)2Zr is determined as 7.78%.     

Phase relations in the Fe-rich region of the Fe-Gd-Mo ternary system at 800 °C

The phase relation in the Fe-rich region of the Fe-Gd-Mo ternary system at 800 °C has been investigated using x-ray powder diffraction followed by Rietveld refinement and electron probe microanalysis. A partial isothermal section contains one ternary ThMn₁₂-type phase, four solution phases (Fe,Mo)₁₇Gd₂, (Fe,Mo)₂₃Gd₆, (Fe,Mo)₃Gd, and (Fe,Mo)₂Gd, one binary phase μ(Fe,Mo), and a liquid phase. The homogeneity range of the ternary ThMn₁₂-type phase is compared to that observed at 1200 °C.     

Phase relations in the Fe-rich region of the Fe-Gd-Mo ternary system at 800 °C

The phase relation in the Fe-rich region of the Fe-Gd-Mo ternary system at 800 °C has been investigated using x-ray powder diffraction followed by Rietveld refinement and electron probe microanalysis. A partial isothermal section contains one ternary ThMn₁₂-type phase, four solution phases (Fe,Mo)₁₇Gd₂, (Fe,Mo)₂₃Gd₆, (Fe,Mo)₃Gd, and (Fe,Mo)₂Gd, one binary phase μ(Fe,Mo), and a liquid phase. The homogeneity range of the ternary ThMn₁₂-type phase is compared to that observed at 1200 °C.     

Solid-liquid phase equilibria at 727 °C in the ternary system Fe-Mg-Si

The solid-liquid phase equilibria in the Fe-Mg-Si ternary system were experimentally investigated at 727 °C by two complementary approaches: reaction to equilibrium of Fe-Mg-Si powder mixtures and growth of reaction zones at the interface of diffusion couples. X-ray powder diffraction, optical metallography (OM), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA) were used to characterize the phases formed in these experiments. It has been shown that except silicon and βFeSi₂, all the compounds and solid solutions stable at 727 °C in the Mg-Si and Fe-Si binary subsystems (Mg₂Si, εFeSi, α₁Fe₃Si, α₂Fe₃Si, and αFe) are in equilibrium at that temperature with a magnesium-rich Mg-Si liquid phase. The liquid simultaneously in equilibrium with FeSi and Mg₂Si contains 3.1±0.2 at.% Si; that involved in the three-phased equilibrium with εFeSi (50 at.% Si) and α₁Fe₃Si (27 at.%Si) contains 1.0±0.05 at.%Si. For lower silicon contents in the liquid, the conjugate solid phases are successively α₁Fe₃Si (DO₃ structure, homogeneity range 27 to 14 at.%Si), α₂Fe₃Si (B2 structure, homogeneity range 14 to 11.5 at.%Si), and αFe (A2 structure, homogeneity range 11.5 to 0 at.% Si). It is however to note that for a silicon content in the liquid as low as about 0.05 at.%, the conjugate solid phase is still quasistoichiometric α₁Fe₃Si with 25 at.% Si.     

Phase equilibria of Zn-Al-Ti ternary system at 450 and 600 °C

The phase relationships in the Zn-Al-Ti system at 450 and 600 °C were experimentally determined using equilibrated alloys method. The specimens were investigated by means of scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray diffractometry. Eleven and eight three-phase regions are confirmed in the 450 and 600 °C isothermal sections, respectively. The Ti₂Al₅ which only exists at high temperature (990-1199.4 °C) in Ti-Al binary system is confirmed in two isothermal sections due to the dissolution of zinc. The T phase is confirmed as a ternary compound rather than an extension phase of TiZn₃ at 450 °C. The T₂ phase is a new ternary phase stable at 450 and 600 °C in Zn-Al-Ti ternary system.     

Phase reactions in the Nb–N system below 1400°C

In continuation of a recent study on high-temperature nitridation of niobium the phase equilibria of the Nb–N system were investigated for T≤1400°C by means of diffusion couples, electron probe microanalysis (EPMA) and differential scanning calorimetry (DSC). The γ-Nb₄N_3±x→δ-NbN_1−x phase transition was investigated as a function of composition and occurs at temperatures between 1070°C (45.2 at.% N) and 1225°C (38.9 at.% N). The equilibrium composition of γ-Nb₄N_3±x in this temperature interval is—depending on the temperature—only 42–44.0 at.% N, hence the transition occurs also in samples with a non-equilibrium composition. It can only be investigated by using in situ methods such as DSC and high-temperature X-ray diffraction because of the fast transition rate which does not permit quenching and which is responsible for the contradictory results in the literature. The congruent transformation η-NbN→δ-NbN_1−x was observed between 1300 and 1320°C. Homogeneity ranges were measured from the phase bands of the diffusion couples by means of EPMA and the results are presented in the form of a phase diagram.     

Determination of isothermal sections of the Co-Nb-Ni and Ni-Mo-Re ternary systems

The isothermal sections of the Co-Nb-Ni ternary system at 1373 K and the Ni-Mo-Re ternary system at 1473 K were determined by means of diffusion triple and electron probe microanalysis (EPMA).The results indicate that there are three three-phase regions found in the Co-Nb-Ni ternary system at 1373 K:(Ni,Co) NbCo3 Ni3Nb,NbCo3 NbCo2 Ni3Nb,and NbCo2 μ Ni3Nb;and four three-phase regions found in the Ni-Mo-Re ternary system at 1473 K:Re Ni χ,Ni NiMo σ,σ χ Ni,and σ Mo NiMo.No ternary eompoond is observed in the two isothermal sections.The isothermal sections arc contrasted with the previous study.