The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Liguo Song - One of the best experts on this subject based on the ideXlab platform.
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effects of alloying elements on phase stability in nb Si System intermetallics materials
Intermetallics, 2007Co-Authors: Shiyu Qu, Liguo SongAbstract:Abstract The effects of alloying elements, such as Ti, Cr, Al and Hf on phase stability in Nb–Si System intermetallics materials have been investigated by scanning electron microscopy (SEM), X-ray energy disperSive spectrum (EDS) and X-ray diffraction (XRD). The binary, ternary and multicomponent alloys have been fabricated by vacuum non-consumable arc melting method. The results showed that Ti and Hf tend to stabilize Nb 3 Si phase to lower temperatures, while Cr and Al promote the direct formation of Nb 5 Si 3 phase. The coordinate effects of alloying elements on microstructures of Nb–Si System intermetallics materials have also been examined.
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Effects of alloying elements on phase stability in Nb–Si System intermetallics materials
Intermetallics, 2007Co-Authors: Yafang Han, Liguo SongAbstract:Abstract The effects of alloying elements, such as Ti, Cr, Al and Hf on phase stability in Nb–Si System intermetallics materials have been investigated by scanning electron microscopy (SEM), X-ray energy disperSive spectrum (EDS) and X-ray diffraction (XRD). The binary, ternary and multicomponent alloys have been fabricated by vacuum non-consumable arc melting method. The results showed that Ti and Hf tend to stabilize Nb 3 Si phase to lower temperatures, while Cr and Al promote the direct formation of Nb 5 Si 3 phase. The coordinate effects of alloying elements on microstructures of Nb–Si System intermetallics materials have also been examined.
H.m. Flower - One of the best experts on this subject based on the ideXlab platform.
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Calculated ternary diagram of Ti–Al–Si System
Materials Science and Technology, 2000Co-Authors: C.r. De Farias Azevedo, H.m. FlowerAbstract:The phase equilibria between β (body centred cubic, bcc), α (hexagonal closed packed, hcp), Ti3 Al–α 2 (hcp), and Ti5 Si3 (hcp) in the Ti–Al–Si System have been investigated in the temperature rang...
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Phase equilibria and transformations in a Ti-Zr-Si System
Metallurgical and Materials Transactions A, 1995Co-Authors: N. H. Salpadoru, H.m. FlowerAbstract:The phase equilibria in the titanium-zirconium rich region of the ternary Ti-Zr-Si System have been studied in the temperature range from 1473 to 1323 K, together with microstructures pres-ent in the as-cast state. DTA, microscopy, X-ray diffraction (XRD), and chemical analySis by X-ray energy-disperSive spectroscopy have been employed. Whereas Ti_5Si_3 nucleates hetero-geneously and grows rapidly in titanium matrices, Ti_3Si exhibits very slow precipitation kinetics. It also is displaced by (Ti, Zr)_5Si_3 and a ternary Silicide in ternary and more complex Systems, explaining its absence in commercial alloys. Zirconium exhibits substantial solid solubility in Ti_5Si_3in ternary alloys, while Ti exhibits only limited solubility in Zr_2Si, Zr_3Si, and Zr_5Si_3. Additionally, a new Silicide of general formula (Ti, Zr)_2Si is formed in ternary alloys with a Ti:Zr ratio ranging from 2.26 to 0.68. Isothermal sections for the Ti-Zr-Si System are presented for temperatures of 1473 and 1323 K.
Shuhong Liu - One of the best experts on this subject based on the ideXlab platform.
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Modeling on the molar volume of the Al–Cu–Mg–Si System
Calphad, 2020Co-Authors: Dandan Huang, Shuhong LiuAbstract:Abstract Molar volume is an important parameter for the microstructure evolution Simulation in materials science. In this work, a comprehenSive study on the temperature– and compoSition–dependents of the molar volume in the Al–Cu–Mg–Si System were performed uSing a CALPHAD (CALculation of PHAse Diagram)–type formalism. Based on the critical review of the available data on molar volume, molar volume of pure elements was described with a thermal expanSion relation. Subsequently, molar volume of the binary solution phases was assessed via CALPHAD technique and the obtained description can reproduce the corresponding experimental data reasonably. Then, molar volume of ternary and higher–order solution phases was extrapolated from the binaries. Molar volumes of the stable compounds in the Al–Cu–Mg–Si System are also assessed in the Similar model of the corresponding Gibbs energy expresSion. USing the established database for the quaternary Al–Cu–Mg–Si System, molar volume of some commercial aluminum alloys was predicted, which shows a good agreement with experimental data from literature.
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Phase equilibria of the Cu–Zr–Si System at 750 and 900 °C
Calphad, 2020Co-Authors: Meng Xiao, Zhijian Liu, Chen Chong, Lianchang Qiu, Huaqing Zhang, Yuling Liu, Shuhong LiuAbstract:Abstract Phase equilibria in the ternary Cu–Zr–Si System at 750 and 900 °C have been experimentally investigated via electron probe micro-analyzer (EPMA) and X-ray diffraction (XRD) analySis on the equilibrated alloys. The results show the presence of eight three-phase regions at 750 °C and seven three-phase regions at 900 °C. Four ternary phase: τ1 (Zr3Cu4Si6, tI26-Zr3Cu4Si6), τ4 (Zr3Cu4Si4, oI22-Gd3Cu4Ge4), τ5 (ZrCuSi, oP12-Co2Si), and τ6 (Zr3Cu4Si2, 2hP9-Fe2P) were confirmed to exist in the Cu–Zr–Si ternary System at 750 and 900 °C. At 900 °C, the dark gray phase, the chemical compoSition of which is close to η-Cu3Si, is confirmed to be the liquid phase. Moreover, the solubilities of Cu in ZrSi2, SiZr and Zr3Si2 are conSiderably small. The solubility of Zr in η-Cu3Si is determined to be negligible. The newly determined phase equilibria of the Cu–Zr–Si System in this work can provide important experimental data for the thermodynamic assessment of the Cu–Zr–Si System and to develop the Cu–Zr–Si alloys and related tranSition metal Silicides.
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Experimental investigation and thermodynamic modeling of the Ce-Si System
Thermochimica Acta, 2016Co-Authors: Dandan Huang, Shuhong Liu, Philip Nash, Ying Tang, Bo SundmanAbstract:Abstract Phase equilibria and thermodynamic properties of the Ce-Si System were studied experimentally by investigating a Si/(Ce,Si) diffuSion couple and thirteen Ce-Si alloys. X-ray diffraction (XRD), electron probe micro-analyzer (EPMA), differential thermal analySis (DTA) and high temperature reaction calorimetry (HTRC) were utilized. A phase with close compoSition of CeSi1.34 and the decompoSition temperature of 1469 K is detected. The eutectic reaction liquid ↔ (Si) + CeSi2 is observed to occurs at 1502.6 K. The enthalpy of formation of CeSi1.68 was measured to be −70 ± 6 kJ mol-atoms−1. A thermodynamic modeling of the Ce-Si System was then performed by conSidering the reliable literature data and the present experimental results. A substitutional solution model was used for the description of the liquid phase, and all of the compounds are treated as stoichiometric ones. The calculated phase diagram and thermodynamic properties uSing the obtained thermodynamic parameters are in good agreement with the experimental data.
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Modeling of the viscoSity in the AL–Cu–Mg–Si System: Database construction
Calphad, 2015Co-Authors: Fan Zhang, Shuhong Liu, Wanqi JieAbstract:Abstract The viscoSity database for the Al–Cu–Mg–Si System was constructed uSing the CALPHAD (CALculation of PHAse Diagram)-type formalism. ViscoSities of pure elements were described with the Arrhenius formula based on the experimental data. Subsequently, viscoSities of the Al–Cu, Al–Si, Al–Mg and Cu–Si binary Systems were assessed via CALPHAD technique and compared with the corresponding experimental data. Due to the lack of experimental data, viscoSities in the Mg–Si and Cu–Mg Systems were estimated by means of the Hirai's equation. The viscoSities of the ternary Al–Cu–Si System were then predicted based on the binary parameters and compared with the experimental results. USing the established viscoSity database for the quaternary Al–Cu–Mg–Si System, the viscoSities of some commercial aluminum alloys were predicted. The reasonable agreement between calculations and experiments in Al-rich corner indicates that the CALPHAD-type database for the viscoSity is valid and the database is suitable for predicting the viscoSity of the commercial Al–Cu–Mg–Si based alloys.
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Heat contents of Sc 5 Si 3 and ScSi intermetallics and thermodynamic modeling of the Sc–Si System
Journal of Thermal Analysis and Calorimetry, 2014Co-Authors: Aning Qin, Shuhong Liu, Dandan Liu, Chong Chen, Man Wang, Philip NashAbstract:The heat contents (HT − H298K) of Sc5Si3 and ScSi in the Sc–Si System were measured by drop calorimetry method from 400 to 1,200 °C in the present work. Based on the critically reviewed thermodynamic properties and phase diagram data from the literature and the present work, the Sc–Si System was assessed by means of the CALPHAD (CALculation of PHAse Diagram) approach. The Gibbs energies of solution phases, Liquid, (αSc), (βSc), and (Si), were modeled by the Redlich–Kister polynomial. All the intermetallic compounds, Sc5Si3, ScSi, αSc3Si5, and βSc3Si5, were described as stoichiometric phases. Finally, a set of self-conSistent thermodynamic parameters for the Sc–Si System was obtained. The calculated phase diagram and thermodynamic properties agree well with the available experimental data.
Philip Nash - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation and thermodynamic modeling of the Ce-Si System
Thermochimica Acta, 2016Co-Authors: Dandan Huang, Shuhong Liu, Philip Nash, Ying Tang, Bo SundmanAbstract:Abstract Phase equilibria and thermodynamic properties of the Ce-Si System were studied experimentally by investigating a Si/(Ce,Si) diffuSion couple and thirteen Ce-Si alloys. X-ray diffraction (XRD), electron probe micro-analyzer (EPMA), differential thermal analySis (DTA) and high temperature reaction calorimetry (HTRC) were utilized. A phase with close compoSition of CeSi1.34 and the decompoSition temperature of 1469 K is detected. The eutectic reaction liquid ↔ (Si) + CeSi2 is observed to occurs at 1502.6 K. The enthalpy of formation of CeSi1.68 was measured to be −70 ± 6 kJ mol-atoms−1. A thermodynamic modeling of the Ce-Si System was then performed by conSidering the reliable literature data and the present experimental results. A substitutional solution model was used for the description of the liquid phase, and all of the compounds are treated as stoichiometric ones. The calculated phase diagram and thermodynamic properties uSing the obtained thermodynamic parameters are in good agreement with the experimental data.
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Heat contents of Sc 5 Si 3 and ScSi intermetallics and thermodynamic modeling of the Sc–Si System
Journal of Thermal Analysis and Calorimetry, 2014Co-Authors: Aning Qin, Shuhong Liu, Dandan Liu, Chong Chen, Man Wang, Philip NashAbstract:The heat contents (HT − H298K) of Sc5Si3 and ScSi in the Sc–Si System were measured by drop calorimetry method from 400 to 1,200 °C in the present work. Based on the critically reviewed thermodynamic properties and phase diagram data from the literature and the present work, the Sc–Si System was assessed by means of the CALPHAD (CALculation of PHAse Diagram) approach. The Gibbs energies of solution phases, Liquid, (αSc), (βSc), and (Si), were modeled by the Redlich–Kister polynomial. All the intermetallic compounds, Sc5Si3, ScSi, αSc3Si5, and βSc3Si5, were described as stoichiometric phases. Finally, a set of self-conSistent thermodynamic parameters for the Sc–Si System was obtained. The calculated phase diagram and thermodynamic properties agree well with the available experimental data.
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Thermodynamic modeling of the V–Si System supported by key experiments
Calphad, 2008Co-Authors: Chao Zhang, Wei Xiong, Philip Nash, Yifang OuyangAbstract:Abstract The V–Si System is reassessed based on a critical literature review involving recently reported data and the present experimental data. These new data include the thermodynamic stability of V 6Si5 and the enthalpies of formation for the compounds calculated by first-principles method. Two alloys were prepared in the region of (Si)+V Si2 and annealed at 1273 K for 14 days. After X-ray diffraction (XRD) and chemical analySis of these alloys were performed, the eutectic reaction (L⇔(Si)+V Si2) temperature was determined by differential thermal analySis (DTA). Self-conSistent thermodynamic parameters for the V–Si System were obtained by optimization of the selected experimental values. The calculated phase diagram and thermodynamic properties agree well with the experimental ones. Noticeable improvements have been made, compared with the previous assessments.
Dong-koo Park - One of the best experts on this subject based on the ideXlab platform.
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Interfacial reactions for the non-stoichiometric TiB_ x /(100)Si System
Journal of Materials Science, 2002Co-Authors: Young-ki Lee, Jung-yuel Kim, You-kee Lee, Gi-seog Eom, Young-kyu Kwon, Min-sang Lee, Chul-min Lim, Dong-kun Kim, Young-chul Jin, Dong-koo ParkAbstract:In order to evaluate the interfacial reactions in the TiB_ x /(100)Si System and the thermal stability of non-stoichiometric TiB_ x films (0 ≤ B/Ti ≤ 2.5), TiB_ x /Si samples prepared by a co-evaporation process were annealed in vacuum at temperatures between 300 and 1000°C. The solid phase reactions were investigated by means of sheet reSistance, X-ray diffraction, transmisSion electron microscopy, X-ray photo-electron spectroscopy, and stress measurement. For TiB_ x samples with a ratio of B/Ti ≥ 2.0, an apparent structural change is not observed even after annealing at 1000°C for 1 h. For samples with a ratio of B/Ti < 2.0, however, there are two competitive solid phase reactions: the formation of a titanium Silicide layer at the interface and the formation of a stoichiometric TiB_2 layer at the surface, indicating the salicide $$(\underline s elf - \underline {al} igned Sil\underline {icide} )$$ process. The sheet reSistance and the film stress in the Ti/Si and TiB_ x /Si Systems are well explained by the solid phase reactions.
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Interfacial reactions for the non-stoichiometric TiBx/(100)Si System
Journal of Materials Science, 2002Co-Authors: Young-ki Lee, Jung-yuel Kim, You-kee Lee, Gi-seog Eom, Young-kyu Kwon, Min-sang Lee, Chul-min Lim, Dong-kun Kim, Young-chul Jin, Dong-koo ParkAbstract:In order to evaluate the interfacial reactions in the TiB x /(100)Si System and the thermal stability of non-stoichiometric TiB x films (0 ≤ B/Ti ≤ 2.5), TiB x /Si samples prepared by a co-evaporation process were annealed in vacuum at temperatures between 300 and 1000°C. The solid phase reactions were investigated by means of sheet reSistance, X-ray diffraction, transmisSion electron microscopy, X-ray photo-electron spectroscopy, and stress measurement. For TiB x samples with a ratio of B/Ti ≥ 2.0, an apparent structural change is not observed even after annealing at 1000°C for 1 h. For samples with a ratio of B/Ti < 2.0, however, there are two competitive solid phase reactions: the formation of a titanium Silicide layer at the interface and the formation of a stoichiometric TiB2 layer at the surface, indicating the salicide \((\underline s elf - \underline {al} igned Sil\underline {icide} )\) process. The sheet reSistance and the film stress in the Ti/Si and TiB x /Si Systems are well explained by the solid phase reactions.
