Browsing by Author "Keslioglu, Kazim"

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Determination of thermodynamic properties of aluminum based binary and ternary alloys
(ELSEVIER, 2015) Altintas, Yemliha; Sezen Aksöz; Keslioglu, Kazim; Necmettin, Maraşlı; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Altintas, Yemliha
In the present work, the Gibbs-Thomson coefficient, solid-liquid and solid-solid interfacial energies and grain boundary energy of a solid Al solution in the Al-Cu-Si eutectic system were determined from the observed grain boundary groove shapes by measuring the thermal conductivity of the solid and liquid phases and temperature gradient. Some thermodynamic properties such as the enthalpy of fusion, entropy of fusion, the change of specific heat from liquid to solid and the electrical conductivity of solid phases at their melting temperature were also evaluated by using the measured values of relevant data for Al-Cu, Al-Si, Al-Mg, Al-Ni, Al-Ti, Al-Cu-Ag, Al-Cu-Si binary and ternary alloys. (C) 2015 Elsevier B.V. All rights reserved.
Experimental Determination of Interfacial Energies for Solid Sn in Equilibrium with Sn-Mg-Zn Liquid
(KOREAN INST METALS MATERIALS, 2015) Altintas, Yemliha; Ozturk, Esra; Aksoz, Sezen; Keslioglu, Kazim; Marasli, Necmettin; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Altintas, Yemliha
The equilibrated grain boundary groove shapes of solid Sn in equilibrium with Sn-Mg-Zn liquid were observed from a quenched sample by using a radial heat flow apparatus. The Gibbs-Thomson coefficient, solid-liquid interfacial energy and grain boundary energy of solid Sn were determined from the observed grain boundary groove shapes. The thermal conductivity of the eutectic solid phase for Sn-8.12 at% Mg-4.97 at% Zn alloy and the thermal conductivity ratio of the liquid phase to the solid phase for Sn-8.12 at% Mg-4.97 at% Zn alloy at eutectic temperature were also measured with a radial heat flow apparatus and a Bridgman-type growth apparatus, respectively. The Gibbs-Thomson coefficient, solid-liquid interfacial energy and grain boundary energy of solid Sn in equilibrium with Sn-Mg-Zn liquid were determined to be (8.3 ± 0.6)×10-8 Km, (118.5 ± 14.2)×10-3 J m-2 and (225.1 ± 29.3)×10-3 J m-2 respectively from observed grain boundary groove shapes. A comparison of present results for solid Sn in the Sn-8.12 at% Mg-4.97 at% Zn alloy with the results obtained in previous works for similar solid Sn in equilibrium with different binary or ternary liquid was made.
The Experimental Determination of Interfacial Energies for Solid Zn in Equilibrium with Zn-Al-Sb Liquid
(SPRINGER, 2015) Altintas, Yemliha; Ozturk, Esra; Aksoz, Sezen; Keslioglu, Kazim; Marasli, Necmettin; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Altintas, Yemliha
The equilibrated grain boundary groove shapes of solid Zn in equilibrium with Zn-Al-Sb liquid were observed from a quenched sample using a radial heat flow apparatus. The Gibbs-Thomson coefficient, solid-liquid interfacial energy, and grain boundary energy of the solid Zn were determined from the observed grain boundary groove shapes. The thermal conductivity of the eutectic solid phase for Zn-0.4 at. pct Al-0.4 at. pct Sb alloy and the thermal conductivity ratio of the liquid phase to the solid phase for Zn-0.4 at. pct Al-0.4 at. pct Sb alloy at eutectic temperature were also measured with a radial heat flow apparatus and a Bridgman-type growth apparatus, respectively.
The experimental determination of thermophysical properties of intermetallic CuAl2 phase in equilibrium with (Al plus Cu plus Si) liquid
(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD24-28 OVAL RD, LONDON NW1 7DX, ENGLAND, 2016) Altintas, Yemliha; Aksoz, Sezen; Keslioglu, Kazim; Marasli, Necmettin; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Altintas, Yemliha
The equilibrated grain boundary groove shapes of solid CuAl2 in equilibrium with (Al + Cu + Si) eutectic liquid were observed from a quenched sample by using a radial heat flow apparatus. The Gibbs-Thomson coefficient, (solid + liquid) interfacial energy and grain boundary energy of the solid CuAl2 were determined from these observed shapes. The thermal conductivity of the eutectic solid and the thermal conductivity ratio of eutectic liquid to the eutectic solid in the (Al + 26.82 wt.% Cu + 5.27 wt.% Si) eutectic alloy at its eutectic melting temperature were also measured with a radial heat flow apparatus and a Bridgman-type growth apparatus, respectively. The three phases of (Al + Cu + Si) alloy have detected as Al solution, Si and theta (CuAl2) phases with EDX composition analysis and the microstructure of these phases were photographed by SEM. (C) 2016 Elsevier Ltd. All rights reserved.
The measurements of electrical and thermal conductivity variations with temperature and phonon component of the thermal conductivity in Sn-Cd-Sb, Sn-In-Cu, Sn-Ag-Bi and Sn-Bi-Zn alloys
(ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER65 RUE CAMILLE DESMOULINS, CS50083, 92442 ISSY-LES-MOULINEAUX, FRANCE, 2016) Altintas, Yemliha; Kaygisiz, Yusuf; Ozturk, Esra; Aksoz, Sezen; Keslioglu, Kazim; Marasli, Necmettin; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Altintas, Yemliha
The electrical and thermal conductivity variations with temperature for lead-free ternary solders, namely Sn-41.39 at.% Cd-6.69 at.% Sb, Sn-49 at.% In-1 at.% Cu, Sn-50 at.% Ag-10 at.% Bi and Sn-32 at.% Bi-3 at.% Zn alloys, were measured by the d.c. four-point probe method and radial heat flow apparatus, respectively. The contributions of electrons and phonons to the thermal conductivity were separately determined by using the measured values of the thermal and electrical conductivities obtained by the Wiedemann-Franz law in the lead-free ternary solders. The percentages of the phonon component of thermal conductivity were found to be in the range of 46-55%, 46-50%, 38-47% and 69-73% for Sn-41.39 at.% Cd-6.69 at.% SU, Sn-49 at.% In-1 at.% Cu, Sn-50 at.% Ag-10 at.% Bi and Sn-32 at.% Bi-3 at.% Zn alloys at the ranges of 318-443 K temperature, respectively. The temperature coefficients (alpha) of electrical conductivity for the lead-free ternary solders were found to be 2.47 x 10(-3), 4.97 x 10(-3), 1.14 x 10(-3) and 1.00 x 10(-3) K-1, respectively. The thermal conductivities of the solid phases at their melting temperature and the thermal temperature coefficients for the lead-free ternary solders were also found to be 47.72 +/- 2.38, 68.57 +/- 3.42, 73.52 +/- 3.67, 37.53 +/- 1.87 W/Km and 1.47 x 10(-3), 1.48 x 10(-3), 1.85 x 10(-3) and 2.21 x 10(-3) K-1, respectively. (C) 2015 Elsevier Masson SAS. All rights reserved.
Thermal conductivity and interfacial energy of solid Bi in the Bi-Ag eutectic system
(SPRINGER, 2015) Altintas, Yemliha; Ozturk, Esra; Aksoz, Sezen; Keslioglu, Kazim; Marasli, Necmettin; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Altintas, Yemliha
The equilibrated grain boundary groove shapes for solid Bi (Bi–2.87 at.%Ag) in equilibrium with Bi–Ag eutectic liquid have been observed from quenched sample with a radial heat flow apparatus. The Gibbs–Thomson coefficient, solid–liquid interfacial energy and grain boundary energy of solid Bi have been determined from the observed grain boundary groove shapes. The variation of thermal conductivity with temperature for eutectic solid phase (Bi–4.7 at.%Ag) has been measured. The ratio of thermal conductivity of equilibrated eutectic liquid phase to eutectic solid phase has also been measured with a Bridgman-type growth apparatus at the melting temperature. The Gibbs–Thomson coefficient, solid–liquid interfacial energy and grain boundary energy of solid Bi in equilibrium with Bi–Ag eutectic liquid were determined to be (9.2 ± 0.6) 9 10–8 K m, (52.7 ± 6.3) 9 10–3 J m–2 and (102.4 ± 13.3) 9 10–3 J m–2, respectively, from observed grain boundary groove shapes.