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B B Straumal - One of the best experts on this subject based on the ideXlab platform.

  • wetting transition of grain boundaries in the sn rich part of the sn bi phase diagram
    Journal of Materials Science, 2011
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    The microstructural evolution of tin-rich Sn–Bi alloys after the grain boundary wetting phase transition in the (liquid + β-Sn) two-phase region of the Sn–Bi phase diagram was investigated. Three Sn–Bi alloys with 30.6, 23, and 10 wt% Bi were annealed between 139 and 215 °C for 24 h. The micrographs of Sn–Bi alloys reveal that the small amount of liquid phase prevented the grain boundary wetting transition to occur during annealing close to the Solidus Line. The melted area of the grain boundary triple junctions and grain boundaries increased with increasing the annealing temperature. When the amount of liquid phase exceeded 34 wt% during annealing, increasing temperature has not affected the wetting behavior of grain boundaries noticeably and led only to the increase of the amount of liquid phase among solid grains in the microstructure. The XRD results show that the phase structure and crystallinity remained unchanged after quenching from various annealing temperatures.

  • study on the Solidus Line in sn rich region of sn in phase diagram
    Journal of Phase Equilibria and Diffusion, 2009
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    Binary phase diagrams are important tools for designing desired alloys. In the Sn-rich region of the Sn-In alloy phase diagram, the Solidus Line appears as a dotted Line in current literature plots to indicate uncertainty. The contour of the Solidus has now been clarified as a result of the present investigation. Four alloys, Sn70In30, Sn75In25, Sn80In20, and Sn85In15 were melted at 300 °C for 10 h and annealed between 120 and 200 °C in the (L + γ) two-phase region. The morphology and chemical compositions of annealed specimens were analyzed using both field emission scanning electron spectroscopy and energy-dispersive x-ray spectrometry. The results reveal that the liquid phase, initially appearing at the eutectic temperature, invades the solid along grain boundaries with penetration gradually increasing with increasing annealing temperature and a granular structure form. The average compositions in grains of Sn70In30, Sn75In25, Sn80In20, and Sn85In15 specimens correspond to the Solidus concentrations, and the Solidus Line and (β + γ)/γ phase boundary can be determined as a fit to these temperature-composition points.

  • Study on the Solidus Line in Sn-Rich Region of Sn-In Phase Diagram
    Journal of Phase Equilibria and Diffusion, 2009
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    Binary phase diagrams are important tools for designing desired alloys. In the Sn-rich region of the Sn-In alloy phase diagram, the Solidus Line appears as a dotted Line in current literature plots to indicate uncertainty. The contour of the Solidus has now been clarified as a result of the present investigation. Four alloys, Sn(70)In(30), Sn(75)In(25), Sn(80)In(20), and Sn(85)In(15) were melted at 300 A degrees C for 10 h and annealed between 120 and 200 A degrees C in the (L + gamma) two-phase region. The morphology and chemical compositions of annealed specimens were analyzed using both field emission scanning electron spectroscopy and energy-dispersive x-ray spectrometry. The results reveal that the liquid phase, initially appearing at the eutectic temperature, invades the solid along grain boundaries with penetration gradually increasing with increasing annealing temperature and a granular structure form. The average compositions in grains of Sn(70)In(30), Sn(75)In(25), Sn(80)In(20), and Sn(85)In(15) specimens correspond to the Solidus concentrations, and the Solidus Line and (beta + gamma)/gamma phase boundary can be determined as a fit to these temperature-composition points

  • The Solidus Line of the Cu-Bi phase diagram
    Journal of Phase Equilibria, 1997
    Co-Authors: L S Chang, B B Straumal, Eugen Rabkin, W. Gust, F. Sommer
    Abstract:

    The solid solubility of Bi in Cu single crystals has been experimentally determined. It is shown that the Solidus Line is a retrograde curve without a monotectic transition. The solid and liquid phases are successfully described with simple thermodynamic models. The experimentally measured maximum solubility of 0.0207 at. % Bi at 975 °C correlates well with that from the model (0.0193 at. % Bi at 968 °C). A Linear temperature dependence of the interchange energies is suggested, and the values of the optimized coefficients are in accordance with those estimated from the thermal expansion coefficients. The calculated thermodynamic functions are in good agreement with the assessed experimental data.

C H Yeh - One of the best experts on this subject based on the ideXlab platform.

  • wetting transition of grain boundaries in the sn rich part of the sn bi phase diagram
    Journal of Materials Science, 2011
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    The microstructural evolution of tin-rich Sn–Bi alloys after the grain boundary wetting phase transition in the (liquid + β-Sn) two-phase region of the Sn–Bi phase diagram was investigated. Three Sn–Bi alloys with 30.6, 23, and 10 wt% Bi were annealed between 139 and 215 °C for 24 h. The micrographs of Sn–Bi alloys reveal that the small amount of liquid phase prevented the grain boundary wetting transition to occur during annealing close to the Solidus Line. The melted area of the grain boundary triple junctions and grain boundaries increased with increasing the annealing temperature. When the amount of liquid phase exceeded 34 wt% during annealing, increasing temperature has not affected the wetting behavior of grain boundaries noticeably and led only to the increase of the amount of liquid phase among solid grains in the microstructure. The XRD results show that the phase structure and crystallinity remained unchanged after quenching from various annealing temperatures.

  • study on the Solidus Line in sn rich region of sn in phase diagram
    Journal of Phase Equilibria and Diffusion, 2009
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    Binary phase diagrams are important tools for designing desired alloys. In the Sn-rich region of the Sn-In alloy phase diagram, the Solidus Line appears as a dotted Line in current literature plots to indicate uncertainty. The contour of the Solidus has now been clarified as a result of the present investigation. Four alloys, Sn70In30, Sn75In25, Sn80In20, and Sn85In15 were melted at 300 °C for 10 h and annealed between 120 and 200 °C in the (L + γ) two-phase region. The morphology and chemical compositions of annealed specimens were analyzed using both field emission scanning electron spectroscopy and energy-dispersive x-ray spectrometry. The results reveal that the liquid phase, initially appearing at the eutectic temperature, invades the solid along grain boundaries with penetration gradually increasing with increasing annealing temperature and a granular structure form. The average compositions in grains of Sn70In30, Sn75In25, Sn80In20, and Sn85In15 specimens correspond to the Solidus concentrations, and the Solidus Line and (β + γ)/γ phase boundary can be determined as a fit to these temperature-composition points.

  • Study on the Solidus Line in Sn-Rich Region of Sn-In Phase Diagram
    Journal of Phase Equilibria and Diffusion, 2009
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    Binary phase diagrams are important tools for designing desired alloys. In the Sn-rich region of the Sn-In alloy phase diagram, the Solidus Line appears as a dotted Line in current literature plots to indicate uncertainty. The contour of the Solidus has now been clarified as a result of the present investigation. Four alloys, Sn(70)In(30), Sn(75)In(25), Sn(80)In(20), and Sn(85)In(15) were melted at 300 A degrees C for 10 h and annealed between 120 and 200 A degrees C in the (L + gamma) two-phase region. The morphology and chemical compositions of annealed specimens were analyzed using both field emission scanning electron spectroscopy and energy-dispersive x-ray spectrometry. The results reveal that the liquid phase, initially appearing at the eutectic temperature, invades the solid along grain boundaries with penetration gradually increasing with increasing annealing temperature and a granular structure form. The average compositions in grains of Sn(70)In(30), Sn(75)In(25), Sn(80)In(20), and Sn(85)In(15) specimens correspond to the Solidus concentrations, and the Solidus Line and (beta + gamma)/gamma phase boundary can be determined as a fit to these temperature-composition points

L S Chang - One of the best experts on this subject based on the ideXlab platform.

  • wetting transition of grain boundaries in the sn rich part of the sn bi phase diagram
    Journal of Materials Science, 2011
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    The microstructural evolution of tin-rich Sn–Bi alloys after the grain boundary wetting phase transition in the (liquid + β-Sn) two-phase region of the Sn–Bi phase diagram was investigated. Three Sn–Bi alloys with 30.6, 23, and 10 wt% Bi were annealed between 139 and 215 °C for 24 h. The micrographs of Sn–Bi alloys reveal that the small amount of liquid phase prevented the grain boundary wetting transition to occur during annealing close to the Solidus Line. The melted area of the grain boundary triple junctions and grain boundaries increased with increasing the annealing temperature. When the amount of liquid phase exceeded 34 wt% during annealing, increasing temperature has not affected the wetting behavior of grain boundaries noticeably and led only to the increase of the amount of liquid phase among solid grains in the microstructure. The XRD results show that the phase structure and crystallinity remained unchanged after quenching from various annealing temperatures.

  • study on the Solidus Line in sn rich region of sn in phase diagram
    Journal of Phase Equilibria and Diffusion, 2009
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    Binary phase diagrams are important tools for designing desired alloys. In the Sn-rich region of the Sn-In alloy phase diagram, the Solidus Line appears as a dotted Line in current literature plots to indicate uncertainty. The contour of the Solidus has now been clarified as a result of the present investigation. Four alloys, Sn70In30, Sn75In25, Sn80In20, and Sn85In15 were melted at 300 °C for 10 h and annealed between 120 and 200 °C in the (L + γ) two-phase region. The morphology and chemical compositions of annealed specimens were analyzed using both field emission scanning electron spectroscopy and energy-dispersive x-ray spectrometry. The results reveal that the liquid phase, initially appearing at the eutectic temperature, invades the solid along grain boundaries with penetration gradually increasing with increasing annealing temperature and a granular structure form. The average compositions in grains of Sn70In30, Sn75In25, Sn80In20, and Sn85In15 specimens correspond to the Solidus concentrations, and the Solidus Line and (β + γ)/γ phase boundary can be determined as a fit to these temperature-composition points.

  • Study on the Solidus Line in Sn-Rich Region of Sn-In Phase Diagram
    Journal of Phase Equilibria and Diffusion, 2009
    Co-Authors: C H Yeh, L S Chang, B B Straumal
    Abstract:

    Binary phase diagrams are important tools for designing desired alloys. In the Sn-rich region of the Sn-In alloy phase diagram, the Solidus Line appears as a dotted Line in current literature plots to indicate uncertainty. The contour of the Solidus has now been clarified as a result of the present investigation. Four alloys, Sn(70)In(30), Sn(75)In(25), Sn(80)In(20), and Sn(85)In(15) were melted at 300 A degrees C for 10 h and annealed between 120 and 200 A degrees C in the (L + gamma) two-phase region. The morphology and chemical compositions of annealed specimens were analyzed using both field emission scanning electron spectroscopy and energy-dispersive x-ray spectrometry. The results reveal that the liquid phase, initially appearing at the eutectic temperature, invades the solid along grain boundaries with penetration gradually increasing with increasing annealing temperature and a granular structure form. The average compositions in grains of Sn(70)In(30), Sn(75)In(25), Sn(80)In(20), and Sn(85)In(15) specimens correspond to the Solidus concentrations, and the Solidus Line and (beta + gamma)/gamma phase boundary can be determined as a fit to these temperature-composition points

  • The Solidus Line of the Cu-Bi phase diagram
    Journal of Phase Equilibria, 1997
    Co-Authors: L S Chang, B B Straumal, Eugen Rabkin, W. Gust, F. Sommer
    Abstract:

    The solid solubility of Bi in Cu single crystals has been experimentally determined. It is shown that the Solidus Line is a retrograde curve without a monotectic transition. The solid and liquid phases are successfully described with simple thermodynamic models. The experimentally measured maximum solubility of 0.0207 at. % Bi at 975 °C correlates well with that from the model (0.0193 at. % Bi at 968 °C). A Linear temperature dependence of the interchange energies is suggested, and the values of the optimized coefficients are in accordance with those estimated from the thermal expansion coefficients. The calculated thermodynamic functions are in good agreement with the assessed experimental data.

Christopher M. Gourlay - One of the best experts on this subject based on the ideXlab platform.

  • Recommended values for the βSn Solidus Line in Sn-Bi alloys
    Thermochimica Acta, 2017
    Co-Authors: S.a. Belyakov, Christopher M. Gourlay
    Abstract:

    Abstract Sn-Bi is an industrially important system that is often incorporated into multicomponent solder alloys. Despite a large body of experimental work, the reported data are in significant disagreement over the βSn Solidus Line and maximum solubility of Bi in βSn. These inconsistencies are often adopted in thermodynamic assessments and databases and might result in the incorrect design of Bi-containing solders. The present study re-measures the βSn Solidus Line using DSC techniques, explores the origin of the inconsistencies in past measurements, and provides recommended values. The work highlights the importance of the equilibration methods used for Solidus measurements and discusses methods to test for full homogenisation.

Mireux Bastien - One of the best experts on this subject based on the ideXlab platform.

  • in situ Microtomography applied to deformation and solidification of aluminium alloys
    2012
    Co-Authors: Mireux Bastien
    Abstract:

    La fissuration à chaud est un défaut majeur intervenant en fin de solidification d'alliages métalliques, lorsque le matériau est encore à l'état semi solide. L'objectif de cette thèse est d'apporter une contribution à la prévision de ce phénomène. Pour cela il est nécessaire de caractériser la déformabilité de la phase solide d'un matériau à l'état semi solide et d'apporter des informations au niveau local sur la microstructure lors de sa déformation (fractions de liquide et de pores, épaisseur de films de liquide, vitesses d'écoulement du liquide, indice de coalescence des pores...). Le comportement macroscopique de la phase solide sur la ligne de Solidus a été déterminé et validé par des essais de compression à chaud. Cette loi de comportement a également été comparée avec plusieurs modèles analytiques. La différence de comportement mécanique entre une microstructure de composition homogène et une microstructure à gradient de composition a été mise en évidence. Des informations microscopiques en temps réel sur des échantillons à l'état semi solide soumis à un effort de traction ont été obtenues par microtomographie in situ standard en conditions isothermes et en solidification. Un modèle analytique prédictif de la fissuration à chaud a été modifié pour mieux rendre compte des valeurs expérimentales. Pour gagner en résolutions temporelle et spatiale, un dispositif de traction destiné à l'utilisation de la microtomographie in situ rapide ou ultra rapide a été conçu et réalisé. Les essais en conditions isothermes et en solidification sont désormais reproductibles sur une microstructure obtenue par refusion. Des phénomènes rapides au sein d'une microstructure très fine sont maintenant observables.Hot tearing is a defect which forms at high solid fraction in solidifying alloys, when the material is still semi solid. This work aims at bringing a contribution to the prevision of this phenomenon. To be able to do that, it is necessary to characterize deformability of the semi-solid alloy solid phase, and also bring local information on microstructure during its straining (liquid and pore fractions, liquid films thickness, liquid flow velocity…). Solid phase macroscopic behaviour on Solidus Line has been determined and validated by hot compression tests. The calculated behaviour law has also been compared with several analytical models. Mechanical behaviour differences between homogeneous and composition gradient microstructure has been put in evidence. Real time microscopic information on tensile tested semi solid samples have been obtained by in situ standard microtomography, in isothermal and solidification conditions. An analytic hot tearing predictive model has been modified to better fit the experimental data. An experimental device has been developed and realized to be able to carry out high and ultra high speed microtomography. These two methods bring better both time and space resolution. High velocity phenomenons in very fine microstructures can thus be visible. Isothermal and solidification conditions tests and now reproducible on remelted samples

  • Microtomographie in situ appliquée à la déformation et la solidification d'alliages d'aluminium
    HAL CCSD, 2012
    Co-Authors: Mireux Bastien
    Abstract:

    Hot tearing is a defect which forms at high solid fraction in solidifying alloys, when the material is still semi solid. This work aims at bringing a contribution to the prevision of this phenomenon. To be able to do that, it is necessary to characterize deformability of the semi-solid alloy solid phase, and also bring local information on microstructure during its straining (liquid and pore fractions, liquid films thickness, liquid flow velocity…). Solid phase macroscopic behaviour on Solidus Line has been determined and validated by hot compression tests. The calculated behaviour law has also been compared with several analytical models. Mechanical behaviour differences between homogeneous and composition gradient microstructure has been put in evidence. Real time microscopic information on tensile tested semi solid samples have been obtained by in situ standard microtomography, in isothermal and solidification conditions. An analytic hot tearing predictive model has been modified to better fit the experimental data. An experimental device has been developed and realized to be able to carry out high and ultra high speed microtomography. These two methods bring better both time and space resolution. High velocity phenomenons in very fine microstructures can thus be visible. Isothermal and solidification conditions tests and now reproducible on remelted samples.La fissuration à chaud est un défaut majeur intervenant en fin de solidification d'alliages métalliques, lorsque le matériau est encore à l'état semi solide. L'objectif de cette thèse est d'apporter une contribution à la prévision de ce phénomène. Pour cela il est nécessaire de caractériser la déformabilité de la phase solide d'un matériau à l'état semi solide et d'apporter des informations au niveau local sur la microstructure lors de sa déformation (fractions de liquide et de pores, épaisseur de films de liquide, vitesses d'écoulement du liquide, indice de coalescence des pores...). Le comportement macroscopique de la phase solide sur la ligne de Solidus a été déterminé et validé par des essais de compression à chaud. Cette loi de comportement a également été comparée avec plusieurs modèles analytiques. La différence de comportement mécanique entre une microstructure de composition homogène et une microstructure à gradient de composition a été mise en évidence. Des informations microscopiques en temps réel sur des échantillons à l'état semi solide soumis à un effort de traction ont été obtenues par microtomographie in situ standard en conditions isothermes et en solidification. Un modèle analytique prédictif de la fissuration à chaud a été modifié pour mieux rendre compte des valeurs expérimentales. Pour gagner en résolutions temporelle et spatiale, un dispositif de traction destiné à l'utilisation de la microtomographie in situ rapide ou ultra rapide a été conçu et réalisé. Les essais en conditions isothermes et en solidification sont désormais reproductibles sur une microstructure obtenue par refusion. Des phénomènes rapides au sein d'une microstructure très fine sont maintenant observables

  • Microtomographie in situ appliquée à la déformation et la solidification d'alliages d'aluminium
    2012
    Co-Authors: Mireux Bastien, Salvo Luc, Suery Michel
    Abstract:

    La fissuration à chaud est un défaut majeur intervenant en fin de solidification d'alliages métalliques, lorsque le matériau est encore à l'état semi solide. L'objectif de cette thèse est d'apporter une contribution à la prévision de ce phénomène. Pour cela il est nécessaire de caractériser la déformabilité de la phase solide d'un matériau à l'état semi solide et d'apporter des informations au niveau local sur la microstructure lors de sa déformation (fractions de liquide et de pores, épaisseur de films de liquide, vitesses d'écoulement du liquide, indice de coalescence des pores...). Le comportement macroscopique de la phase solide sur la ligne de Solidus a été déterminé et validé par des essais de compression à chaud. Cette loi de comportement a également été comparée avec plusieurs modèles analytiques. La différence de comportement mécanique entre une microstructure de composition homogène et une microstructure à gradient de composition a été mise en évidence. Des informations microscopiques en temps réel sur des échantillons à l'état semi solide soumis à un effort de traction ont été obtenues par microtomographie in situ standard en conditions isothermes et en solidification. Un modèle analytique prédictif de la fissuration à chaud a été modifié pour mieux rendre compte des valeurs expérimentales. Pour gagner en résolutions temporelle et spatiale, un dispositif de traction destiné à l'utilisation de la microtomographie in situ rapide ou ultra rapide a été conçu et réalisé. Les essais en conditions isothermes et en solidification sont désormais reproductibles sur une microstructure obtenue par refusion. Des phénomènes rapides au sein d'une microstructure très fine sont maintenant observables.Hot tearing is a defect which forms at high solid fraction in solidifying alloys, when the material is still semi solid. This work aims at bringing a contribution to the prevision of this phenomenon. To be able to do that, it is necessary to characterize deformability of the semi-solid alloy solid phase, and also bring local information on microstructure during its straining (liquid and pore fractions, liquid films thickness, liquid flow velocity ). Solid phase macroscopic behaviour on Solidus Line has been determined and validated by hot compression tests. The calculated behaviour law has also been compared with several analytical models. Mechanical behaviour differences between homogeneous and composition gradient microstructure has been put in evidence. Real time microscopic information on tensile tested semi solid samples have been obtained by in situ standard microtomography, in isothermal and solidification conditions. An analytic hot tearing predictive model has been modified to better fit the experimental data. An experimental device has been developed and realized to be able to carry out high and ultra high speed microtomography. These two methods bring better both time and space resolution. High velocity phenomenons in very fine microstructures can thus be visible. Isothermal and solidification conditions tests and now reproducible on remelted samples.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF