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Öğe Determination of the thermal properties of Al-Zn-Mg alloy(Redakcia Kovove Materialy, 2021) Cadirli, E.; Ustun, E.; Buyuk, U.; Kaya, H.In this work, the thermal conductivity, enthalpy of fusion, specific heat capacity, and thermal diffusivity of the Al-5.5Zn-2.5Mg (wt.%) ternary alloy have been investigated. Thermal conductivity of as-cast Al-5.5Zn-2.5Mg alloy was measured using comparison cut bar method in the temperature range of 323-723 K. With the increase of temperature, thermal conductivity decreased gradually in as-cast Al-5.5Zn-2.5Mg alloy. The thermal temperature coefficient was calculated from the respective graph. The enthalpy of fusion and the specific heat capacity during the transformation were also determined. Thermal diffusivity changes were calculated as a function of temperature through the obtained thermal data. It was observed that thermal diffusivity values decreased with increasing temperature.Öğe Directionally Solidified Al-Cu-Si-Fe Quaternary Eutectic Alloys(Maik Nauka/Interperiodica/Springer, 2020) Buyuk, U.; Engin, S.; Kaya, H.; Cadirli, E.; Marasli, N.Directional solidification of eutectic alloys attracts considerable attention because of microhardness, tensile strength, and electrical resistivity affected by eutectic structures. In this research, solidification processing of Al-Cu-Si-Fe (Al-26 wt % Cu-6.5 wt % Si-0.5 wt % Fe) quaternary eutectic alloy by directional solidification is examined. The alloy was prepared by vacuum furnace and directionally solidified in Bridgman-type equipment. During the directional solidification process, the growth rates utilized varied from 8.25 to 164.80 mu m/s. The Al-Cu-Si-Fe system showed a eutectic transformation, which resulted in the matrix Al, lamellar Al2Cu, plate Si, and plate Al7Cu2Fe phases. The eutectic spacing lambda(Al2Cu) between lamellae of Al2Cu, as well as-lambda (Si), between plates of Si phase,-was measured. Additionally, the microhardness, tensile strength, and electrical resistivity of the studied alloy were determined using directionally solidified samples, and the experimental relationships between them were obtained. It was found that the microhardness, tensile strength, and electrical resistivity were affected by both eutectic spacing and the growth rate.Öğe Influence of solidification rate and alloying elements on structure, mechanical and electrical properties of Al-Cu-X alloys(Redakcia Kovove Materialy, 2021) Kalkanoglu, A.; Kaya, H.; Buyuk, U.; Cadirli, E.The present work aims to explore the effects of the alloying elements (Si, Bi, Sb, Ni, and Co) and solidification rates (V) on the microstructural morphology, microhardness, ultimate tensile strength and electrical resistivity of Al-Cu based eutectic alloys by Bridgman-type solidification apparatus, metallographic observation, scanning electron microscopy, microhardness testing, tensile testing and four-point probe testing. Firstly, the Al-33 Cu-2X (wt.%) samples were produced by using metals of high purity (> 99.95 %) in the vacuum and hotfilling furnaces; these alloys were unidirectionally solidified under different solidification rates, V (8.28-167.08 mu m s(-1)) and constant temperature gradient, G (average 8.50 K mm(-1)). Secondly, metallographic examination and measurement processes: lamellar spacings (lambda), microhardness (HV), ultimate tensile strength (UTS) and electrical resistivity (rho) were measured and expressed as functions of V. It has been found that the addition of the alloying elements (AE) content in Al-Cu eutectic as well as increasing of V lead to a decrease of lamellar spacings. On the contrary, the values of HV, UTS, and rho increase with increasing V values and the addition of alloying elements. Relationships between lambda-V, lambda-HV, lambda-UTS (sigma) and lambda-rho were found by regression analysis, and the results found in this research were compared with the previous similar studies.Öğe Investigation of the Thermal and Electrical Properties of Al-1.9Mn-xFe Ternary Alloys(Pleiades Publishing Inc, 2021) Cadirli, E.; Ustun, E.; Buyuk, U.; Kaya, H.In this work, the thermal conductivity, electrical conductivity, enthalpy of fusion, specific heat capacity and thermal diffusivity of the Al-1.9Mn-xFe ternary alloys (x: 0.5, 1.5 and 5.0 wt %) have been investigated. Thermal conductivity of as-cast Al-1.9Mn-xFe alloys were measured using comparison cut bar method in the temperature range of 323-823 K. Variation of electrical conductivity with the temperature in the range of 290-580 K for studied alloys was also measured by using a standard four-point probe technique. With the increase of temperature and Fe content, thermal conductivity and electrical conductivity decreased gradually in as-cast Al-1.9Mn-xFe alloys. The thermal temperature coefficient (alpha TTC) and the electrical temperature coefficient (alpha ETC) were calculated from the respective graphs. The electrical conductivities of the samples were predicted with the Wiedemann-Franz and Smith-Palmer equations by using the measured thermal conductivity values. The electrical conductivity values estimated from the Smith-Palmer equation were closer to the experimentally measured electrical conductivity values. The enthalpy of fusion and the specific heat capacity during the transformation were also determined. Thermal diffusivity changes were calculated as a function of temperature through the obtained thermal data. It was observed that thermal diffusivity values decreased with increasing temperature.Öğe Microstructure, microhardness, tensile, electrical, and thermal properties of the Al-Mn-xSi ternary alloys(Redakcia Kovove Materialy, 2020) Kaya, H.; Cadirli, E.; Buyuk, U.The effect of Si content (0.5, 1.5, and 5 wt.%) and growth velocity on the microstructure, microhardness, ultimate tensile strength, electrical resistivity, enthalpy, and specific heat properties of the directionally solidified Al-Mn eutectic alloy have been investigated. Al-1.94Mn-xSi (x = 0.5, 1.5, 5 wt.%) samples were prepared from pure metals (99.99 % purity) under the vacuum. These alloys were directionally solidified under constant temperature gradient G (4.9 K mm(-1)) and different growth velocities V (from 8.3 to 978 mu m s(-1)) in a Bridgman-type growth apparatus. Measurements of primary dendrite arm spacing (lambda), microhardness (HV), ultimate tensile strength (UTS) and electrical resistivity (rho) of the samples were carried out and then expressed as functions of growth velocity and Si content (C-o). Additionally, the enthalpy of fusion (Delta H) and specific heat capacity (C-p) for the same alloys were determined by a differential scanning calorimeter (DSC) from the heating curves. It has been found that the values of HV, UTS, and rho increase with increasing values of V and C-o. On the contrary, the values of lambda decrease with increasing V. The increasing Si content in Al-Mn leads to a decrease of Delta H and C-p.Öğe Physical Properties of Directionally Solidified Al-1.9Mn-5Fe Alloy(Springer, 2021) Yilmazer, I; Cadirli, E.; Kaya, H.; Buyuk, U.Al-1.9Mn-5Fe (wt.%) alloy was prepared by adding 5 wt.% Fe to the eutectic Al-Mn alloy. This alloy undergone controlled solidification under four different growth velocities (V) in Bridgman-type furnace. Eutectic spacings (lambda), microhardness (HV), ultimate tensile strength (sigma(U)) and electrical resistivity (rho) of these alloys were determined. While the HV and sigma(U) increased with increasing V values or decreasing lambda, the elongation (delta) values decreased. In addition, relationships between these parameters were investigated using linear regression analysis. Microstructure photographs of directionally solidified samples were taken by optical microscope and scanning electron microscope (SEM). The eutectic spacings were measured from these photographs. The relationships among growth velocity (V), eutectic spacing (lambda), microhardness (HV), ultimate tensile strength (sigma(U)) and electrical resistivity (rho) were measured by suitable method and tests. The rho measurements were carried out depending on V and temperature (T). While temperature coefficient of resistivity (alpha(TCR)) was calculated from the rho-T curve, the values of thermal conductivity (K) predicted by Wiedemann-Franz (W-F) and Smith-Palmer (S-P) equations. It was found that the microstructure, microhardness, tensile strength and electrical resistivity were affected by both eutectic spacing and the growth velocity.Öğe Physical Properties of Directionally Solidified Al-1.9Mn-5Fe Alloy (Nov, 10.1007/s11665-020-05253-3, 2020)(Springer, 2021) Yilmazer, I.; Cadirli, E.; Kaya, H.; Buyuk, U.[Abstract Not Available]
