WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Citation - WoS: 1Citation - Scopus: 1The Variations of Electrical Resistivity and Thermal Conductivity With Growth Rate for the Zn-Al Eutectic Alloy(Springer, 2021-06-24) Marasli, Necmettin; Bayram, Umit; Aksoz, SezenThe Zn-Al-Cu alloy (Zn-5wt%Al-0.5wt%Cu) is solidified with different growth rates (V = 8.45-2087.15 mu m s(-1)) at a constant temperature gradient (G = 3.67 K mm(-1)) using Bridgman-type directional solidification apparatus (BTDSA). The thermal conductivity (K) and electrical resistivity (rho) for the Zn-Al-Cu alloy solidified with the different V values are measured by the longitudinal heat flow method (LHFM) and DC four-point probe technique (FPPT), respectively. The lambda and K decrease with the increasing V, while the q increases with increasing V in the Zn-Al-Cu eutectic alloy. The dependences of rho and K on lambda and V for the Zn-Al-Cu eutectic alloy are obtained as rho = 9.98 x 10(-8)lambda(-0.18), q = 7.03 x 10(-8) V-0.07, K = 110.91 lambda(0.104) and K = 144.59V(-0.040), respectively. The melting enthalpy (DHf) and specific heat difference between solid and liquid phases (Delta C-p) for the Zn-Al-Cu eutectic alloy are determined as 113.89 J g(-1) and 0.172 J g(-1) K-1, respectively, by the differential scanning calorimetry (DSC).Article Citation - WoS: 4Citation - Scopus: 4Investigations of Electrical Resistivity and Thermal Conductivity Dependences on Growth Rate in the Al-Cu Eutectic Alloy(Springer/plenum Publishers, 2021-05-03) Marasli, Necmettin; Bayram, UmitDirectional solidification of Al-Cu-Ti (Al-33wt%Cu-0.1wt%Ti) eutectic alloy was done with a growth rate range (V = 8.58 to 2038.65 mu m.s(-1)) at a temperature gradient of 6.45 K.mm(-1) using Bridgman-type directional solidification furnace. The measurements of thermal conductivity (K) and electrical resistivity (rho) for the Al-Cu-Ti alloy solidified with the different values of V were made by the longitudinal heat flow method (LHFM) and DC four-point probe technique (FPPT). While the highest values of K and rho were determined to be 236.04 W.K-1.m(-1) and 5.91 x 10(-8) omega m, respectively, at 8.58 mu m.s(-1), the lowest values of K and rho were obtained to be 199.82 W.K-1.m(-1) and 12.11 x 10(-8) omega m, respectively, at 2038.65 mu m.s(-1). The K and rho dependences on V were obtained to be K=259.96xV(-0.032) and rho=4.47x10(-8)V(0.13) from linear regression analysis. The fusion enthalpy ( increment H) and specific heat difference between solid and liquid ( increment C-P) for the Al-Cu-Ti were also determined to be 222.69 J.g(-1) and 0.266 Jg(-1).K-1, respectively, by means of differential scanning calorimetry (DSC).Article Citation - WoS: 1Citation - Scopus: 1Effect of Sn Contents on Thermodynamic, Microstructure and Mechanical Properties in the Zn90-Bi10 and Bi88-Zn12 Based Ternary Alloys(Springer, 2019-01-10) Esener, Pinar Ata; Altintas, Yemliha; Bayram, Umit; Ozturk, Esra; Marasli, Necmettin; Aksoz, SezenThe thermal conductivity variations with temperature for Zn90-x-Sn-x-Bi10 (x=5,10, 40 and 85wt%) and Bi88-x-Sn-x-Zn-12 (x=1.39, 43.26 and 79.3wt%) alloys were measured by using the linear heat flow method. From thermal conductivity-temperature plots, the coefficients of thermal conductivity for the Zn-Sn-Bi alloys were calculated. The microstructures of Zn-Sn-Bi alloys were observed using scanning electron microscopy (SEM). The existing phases into microstructure were identified energy dispersive X-ray (EDX) analysis. The melting temperatures, the enthalpy of fusion and specific heat change between the liquid and solid phases in the Zn-Sn-Bi alloys were determined from Differential Scanning Calorimetry (DSC) trace. The tensile strength and microhardness of the alloys were measured using a Shimadzu Universal Testing Instrument (Type AG-10 KNG) and Future-Tech FM-700 model microhardness device.Article Citation - WoS: 5Citation - Scopus: 5Directional Solidification of Al-Si Irregular Ternary Eutectic Alloy and Thermophysical Properties(Springer, 2022-10-03) Bayram, UmitDirectional solidification of Al-11.75 wt pct Si-2.15 wt pct Ti irregular eutectic alloy which has an 843.83 K melting point, was done with different growth rates (V = 8.51 to 2065.18 mu m s(-1)) at a temperature gradient (G) of 8.36 K mm(-1) using Bridgman-type directional solidification apparatus (BTDSA). Scanning electron microscopy (SEM)-Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were used to characterize all phases forming the alloy. The average values of interflake spacing (lambda(T)) were measured from transverse sections of the directionally solidified samples with standard techniques. The dependency of lambda(T) was experimentally obtained using linear regression analysis for low, high, and all growth rates. It was observed that the lambda(T) values tended to decrease with increasing V values; therefore, the interflake structures came closer. The fusion enthalpy (Delta H-f) and specific heat difference between solid and liquid (Delta C-p) for the Al-Si-Ti eutectic alloy were found as 376.12 J g(-1)and 0.659 J g(-1) K-1, respectively, by the differential scanning calorimetry (DSC). All results obtained in the present work were compared with the eutectic theory and the Al-based similar experimental results in the literature. [GRAPHICS] .