查看更多>>摘要：A thermodynamic evaluation of the binary Co-V system has been done using experimental thermochemical and phase diagram data. A consistent thermodynamic description, using a Redlich-Kister model for solution phases and sublattice models for the intermetallics, was obtained, and it agreed well with the critically evaluated experimental data. The model for the solid phases accounts for the magnetic contribution to the Gibbs energy. The addition of a composition dependent magnetic term also led to the prediction of an fcc-Co miscibility gap. The model parameters have been determined using a computerized optimization technique. Several diagrams and tables concerning phase equilibria are presented.
查看更多>>摘要：Through the application of the maximum bubble pressure and dilatometric method, density and surface tension were investigated. The experiments were conducted in the temperature range from 583 K <= T <= 1257 K. The surface tension was measured for pure antimony and for six liquid Sb-Sn alloys (mole fractions X_(Sn) =0.2,0.4,0.6,0.8,0.9, and 0.935 mm~2) and measurements of the density were only for alloys. It has been observed that both surface tension and density show linear dependence on temperature. The temperature-concentration relation of both surface tension and density were determined with minimization procedures. The surface tension isotherms calculated at 873 K and 1273 K show slight negative deviations from linearity changes, but the observed maximal differences did not exceed 30 mN m~(-1). The surface tension calculated from Butler's model was higher than the experimental value for most concentrations and also showed curvilinear temperature dependence. The experimental densities and the molar volumes of the Sb-Sn liquid alloys conform very closely to ideal behavior with differences comparable to the experimental errors.
查看更多>>摘要：Phase relations in the ternary system Al-Ru-Ti were studied on arc-melted alloys and specimens annealed at 1100 deg C, 950 deg C, and 800 deg C employing optical and electron microscopy, x-ray diffraction, and electron probe microanalysis. The results, in combination with an assessment of all literature data available, were used to construct liquidus and solidus surfaces, a series of isothermal sections, and a Schulz-Scheil diagram monitoring solidification (crystallization) in thermodynamic equilibrium. The crystal structure of the ternary G-phase was determined by x-ray single crystal diffraction to be a filled variant of the Th_6Mn_(23)-type (space group Fm 3-bar m). Furthermore, a new ternary compound with AuCu_3-type structure was detected.
查看更多>>摘要：The Zn-rich corner of the 450 deg C isothermal section of the Zn-Fe-Sn system was experimentally determined. Within the composition range explored in this study, the liquid phase was found in equilibrium with the ternary extensions of three binary Zn-Fe phases, the zeta delta, and GAMMA_1 phases. The zeta phase contains practically no Sn in solid solution; Sn solubility limits in the delta and GAMMA_1 phases were 2.2 at. percent and 7.0 at. percent, respectively. The only Fe-Sn compound detected in this study was FeSn, which co-existed with the GAMMA_1 phase. When its Sn content was lower than approximately 26 at. percent, the liquid solidified in water quenching as a degenerated eutectic consisting of a mixture of eta-Zn and beta-Sn co-existing with primary zeta crystallites. When its Sn content exceeded approximately 70 at. percent, the liquid transformed into metallic glass containing mostly Sn, Zn, and a small amount of Fe upon water quenching from 450 deg C.
查看更多>>摘要：In this paper, we modify the VDW equation of state by adding a temperature factor to it. As a result, we produce a good phase diagram and the correlation of the reduced pressure and the reduced temperature when a balanced liquid-gas coexistence canonical argon-like system is considered.
查看更多>>摘要：The Fe-Zn phase diagram (Fig. 1) exhibits a gamma loop, extensive solubility of Zn in bcc Fe (alpha), and four intermediate phase: GAMMA, GAMMA_1, delta [1982 Kub]. The GAMMA phase forms peritectically at 782 deg C. The GAMMA_1 phase forms peritectoidally at 550 deg C. The delta and zeta phase form through peritectic reactions at 665 and 530 deg C, respectively. The final solidification at the Zn end yields zeta + (Zn). The GAMMA (Fe_3Zn_(10)) phase with a homogeneity range of 68.5-82.5 at. Percent Zn has the Cu_5Zn_8 type bcc strcture. GAMMA_1 (Fe_(11)Zn_(40)) has a range of 75-81 at. Percent Zn and is a related structure with a large fcc unit cell containing 8 formula units per cell. (GAMMA and GAMMA_1 are denoted as GAMMA_1 and GAMMA_2, respectively, in [1993 Bur] and other publication of Perrot and coworkers. In some recent publications, Tang denotes the GAMMA_1 phase as GAMMA'). The delta (FeZn_(10)) phase (denoted delta_1 by some authors) has a composition range of 86.5-91.8 at. percent Zn and hexagonal symmetry. The zeta (FeZn_(13)) phase (92.8-94 at. percent Zn) has the CoZn_(13) type monoclinic structure. Table 1 lists the crystal structure data on the intermediate phase of this system. Recently, [1994 Gra] determined the details of the site occupancy in the Fe-Zn compounds, using Mossbauer spectroscopy and x-ray diffraction.
查看更多>>摘要：The previous review of this system [1992 Rag] presented a liquidus surface, two isothermal sections at 700 and 450 deg C, and a reaction scheme, mainly from the work of [1970 Kos], [1973 Ure], and [1990 Che]. In the last decade, a number of studies have examined the phase equilibria of this system, especially in Zn rich alloys at typical galvanizing temperatures. Binary Systems The Al-Fe phase diagram [1993 Kat] shows that the face-centered cubic (fcc) solid solution based on Fe is restricted by a gamma loop. The body-centered cubic (bcc) solid solution alpha exists in the disordered A 2 form, as well as the ordered B 2 and D0_3 forms. Apart from the high temperature phase epsilon, there are three other intermediate phases in the system: FeAl_2, Fe_2Al_5 (also denoted eta), and FeAl_3 (also called theta). The Al-Zn phase diagram updated by [1995 Oka] depicts a eutectic reaction at 381 deg C between (Al) and (Zn). In the (Al) region, a miscibility gap occurs in the solid state with the monotectoid reaction at 277 deg C and the critical temperature at 351.5 deg C. The Fe-Zn phase diagram (Fig. 1 under the Fe-Zn system on page 544) exhibits a gamma loop, extensive solubility of Zn in bee Fe (alpha), and four intermediate phases: GAMMA, GAMMA_1, delta, and zeta. For crystal structure data of the Fe-Zn compounds, see Table 1 under Fe-Zn. The details of the site occupancy in the Fe-Zn compounds in alloys containing up to 1 wt. percent Al were studied by [1995 Cod], using Mossbauer spectroscopy and x-ray diffraction.
查看更多>>摘要：The previous review of this system by [1986 Sin] presented three isothermal sections at 800, 650, and 500 deg C and a reaction scheme, mainly from the work of Koster [1956 Kos]. Recently, [1995 Tak] determined four isothermal sections in the temperature range of 880-700 deg C, with special reference to the effect of the magnetic transitions on the phase equilibria. Binary Systems The Co-Fe phase diagram [1984 Nis] is characterized by an extremely narrow solidification range. The fcc Fe forms a continuous solid solution gamma with alpha Co over a wide range of temperature. The gamma -> (alpha Fe) (bcc) transformation temperature is initially raised by the addition of Co, reaching a maximum of 985 deg C at 45 at. percent Co. At 730 deg C, the bcc phase of equiatomic composition orders to a CsCl type B 2 structure. The Co-Zn phase diagram compiled by [Massalski 2] depicts a number of intermediate phases. The CoZn (beta) phase is listed as Cu type fcc structure by [Pearson 3] and W type bcc structure by [Massalski 2]. The CoZn (beta_1) phase has the beta Mn type cubic structure. Co_5Zn_(21) (denoted F by [1995 Tak] and gamma by [Massalski 2]) has the Al_4Cu_9 type c bic structure. The CoZn_9 phase (denoted gamma_1 by [Massalski 2]) has a gamma-brass related cubic structure [1986 Sin]. The CoZn_(13) phase (denoted gamma_2 by [Massalski 2]) is monoclinic and is isostructural with zeta (FeZn_(13)). For more details on the crystal structure data, see [Pearson 3] and [1986 Sin]. The Fe-Zn phase diagram (Fig. 1 under the Fe-Zn system page 544) exhibits a gamma loop, extensive solubility of Zn in bcc Fe (alpha), and four intermediate phases: GAMMA, GAMMA_1, delta and zeta. For crystal structure data of the Fe-Zn compounds, see Table 1 under Fe-Zn.
查看更多>>摘要：Chromium from the stainless steel rollers used for driving the steel sheets into a galvanizing bath can enter the molten Zn and influence the reactions between the steel and the bath. Recently, [2000 Reu] determined a metastable isothermal section for this system at 460 deg C, applicable to industrial galvanizing conditions. Binary Systems The Fe-Cr phase diagram was reviewed by [1993 Itk]. Here, a gamma loop restricts the fcc phase gamma to about 11 wt. percent Cr. The bcc phase alpha is stable over a large region. The intermediate phase sigma, forms from alpha at 820 deg C around the mid-composition and decomposes eutectoidally at 545 deg C to Fe-rich and Cr-rich bcc phases. A partial phase diagram of the Cr-Zn system for Zn-rich alloys [1992 Mos] depicts two intermediate phases: CrZn_(17) (hexagonal) and CrZn_(13) (monoclinic) CrZn_(13) is isostructural with zeta (FeZn_(13)). A thermodynamic assessment of the Zn rich part of this system was reported very recently [2003 Reu]. The Fe-Zn phase diagram (Fig. 1 under the Fe-Zn system on page 544) exhibits a gamma loop, extensive solubility of Zn in bcc Fe (alpha), and four intermediate phases: GAMMA, GAMMA_1, delta, and zeta. For crystal structure data of the Fe-Zn compounds, see Table 1 under Fe-Zn.
查看更多>>摘要：The previous review of this ternary system by [1991 Bha] presented from the work of [1974 Bud] three isothermal sections at 1000, 720, and 625 deg C for alloys containing Mn up to 30 at. percent. Recently, Reumont et al. [1995 Reu] determined an isothermal section for this system at 450 deg C. Binary Systems The Fe-Mn phase diagram [1993 Oka] contains no intermediate phases. It depicts a wide range of mutual solid solubility between fcc Fe and gamma Mn. At 450 deg C, the stable solid solutions are: bcc Fe based alpha has a range of 0-3 at. percent Mn, the fcc solid solution gamma has a range of 25.5-52 at. percent Mn, and (alpha Mn) is stable between 69.5-100 at. percent Mn. The Fe-Zn phase diagram (Fig. I under the Fe-Zn system on page 544) exhibits a gamma loop, extensive solubility of Zn in bcc Fe (alpha), and four intermediate phases: GAMMA, GAMMA_1, delta, and zeta. For crystal structure data of the Fe-Zn compounds, see Table 1 under Fe-Zn. The Mn-Zn phase diagram [1990 Oka] depicts a number of intermediate phases. Due to disagreements between various reports and the lack of confirmatory work, many parts of the diagram are tentative and qualitative [1990 Oka]. At the temperature of interest here (450 deg C), the stable phases are (alpha Mn), (beta Mn), the three modifications of the hexagonal epsilon phase (epsilon, epsilon_1, and epsilon_2), the hexagonal MnZn_9 phase (denoted delta by [1990 Oka]), and the liquid. The low temperature modification of MnZn_9 (denoted delta_1 by [1990 Oka]) is isostructural with delta (FeZn_(10)) [1995 Reu] and forms peritectoidally at 424 deg C [1990 Oka]. The monoclinic MnZn_(13) phase, which is isostructural with zeta (FeZn_(13)), forms peritectically at 428 deg C [1990Oka].
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