Browsing by Author "Fatih Kilicaslan M."

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Effect of Co on Si and Fe-containing intermetallic compounds (IMCs) in Al-20Si-5Fe alloys
(2012-10-30) Fatih Kilicaslan M.; Yilmaz F.; Hong S.; Uzun O.
The effects of cobalt addition on microstructure and mechanical properties of Al-20Si-5Fe-XCo (X=0, 1, 3, and 5) alloys were reported in this study. The alloys were produced by both conventional sand casting and melt-spinning at 20. m/s disk velocity. Microstructures of the samples were investigated using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Vickers micro-hardness tester was used for hardness measurements. Results showed that Co addition can alter morphology of Fe-bearing intermetallic compounds (IMCs) from long rod/needle-like structures to short rod-like ones, and lead to a more homogenous distribution in the microstructure. Addition of 5. wt% Co leads to a decrease in average size of the primary silicon phases in as-cast Al-Si alloys. In melt-spun alloys, with the addition of Co, the microstructure became finer and more homogenously distributed, while thickness of the featureless zone has seen great increase. The optimum Fe to Co ratio was found to be 1 for suppressing the undesirable effect of Fe-bearing acicular/needle-like intermetallic compounds. © 2012 Elsevier B.V.
Effect of Different Production Methods on the Mechanical and Microstructural Properties of Hypereutectic Al-Si Alloys
(2014-10-01) Fatih Kilicaslan M.; Uzun O.; Yilmaz F.; Çağlar S.
In this study, the effects of different production methods like melt spinning, high-energy ball milling, and combined melt spinning and high-energy ball milling on the mechanical and microstructural properties of hypereutectic Al-20Si-5Fe alloys were investigated. While microstructural and spectroscopic analyses were performed using scanning electron microscopy and X-ray diffractometry, mechanical properties were measured using a depth-sensing indentation instrument with a Berkovich tip. Microstructural and spectroscopic analyses demonstrate that high-energy ball milling process applied on the melt-spun Al-20-Si-5Fe alloy for 10 minutes brings about a reduction in the size of silicon particles and intermetallic compounds. However, further increase in milling time does not yield any significant reduction in size. High-energy ball milling for 10 minutes on the starting powders is not enough to form any intermetallic phase. According to the depth-sensing indentation experiments, high-energy milling of melt-spun Al-20Si-5Fe alloys shows an incremental behavior in terms of hardness values. For the Al-20Si-5Fe alloys investigated in this study, the production technique remarkably influences their elastic–plastic response to the indentation process in terms of both magnitude and shape of P-h curves.
Effect of Sc addition on the microstructure and mechanical properties OF MELT-SPUN Al-10Ni alloys
(2018-01-01) Fatih Kilicaslan M.; Karakose E.
In the present work, rapidly solidified Al-10Ni-XSc (X = 0, 1 and 2) alloys were fabricated by melt spinning under Ar atmosphere. The Effects of Sc on the microstructural and thermal properties and microhardness values were investigated by scanning electron microscopy (SEM), X-ray diffractometer (XRD) and a Vickers microhardness tester. Experimental results revealed that the addition of 2 wt. % Sc to melt-spun Al-10Ni alloys changed their brittle nature and hindered formation of cracks. The addition of Sc to melt-spun Al-10Ni alloys also changed the morphology of Al3Ni intermetallics from an acicular/needle – like to a rounded particle-like structure and led to reduction in their size. Formation of the metastable Al9Ni2 phase was observed due to the higher constitutional undercooling caused by Sc addition. A considerable improvement in microhardness value (from 95. 9 to 230. 1 HV) was observed with the addition of Sc.
Production of melt-spun al-20si-5fe alloy and boron carbide (B4C) Composite material
(2018-01-01) Fatih Kilicaslan M.; Uzun A.; Karakose E.
In this study, metal matrix composite materials containing melt-spun Al-20Si-5Fe alloys and boron carbide was produced by high energy ball milling and then hot pressing at 200 MPa pressure and 450°C. Mechanical and microstructural characterizations were performed by using an optical microscopy, X-Ray diffractometer, and dynamic microhardness tester. It was observed that boron carbide particles were homogenously distributed in the microstructure and values of microhardness and elastic modules were averagely 830 MPa and 42 GPa, respectively.
Recovery of indium from used LCD panel by a time efficient and environmentally sound method assisted HEBM
(2013-03-01) Lee C.H.; Jeong M.K.; Fatih Kilicaslan M.; Lee J.H.; Hong H.S.; Hong S.J.
In this study, a method which is environmentally sound, time and energy efficient has been used for recovery of indium from used liquid crystal display (LCD) panels. In this method, indium tin oxide (ITO) glass was crushed to micron size particles in seconds via high energy ball milling (HEBM). The parameters affecting the amount of dissolved indium such as milling time, particle size, effect time of acid solution, amount of HCl in the acid solution were tried to be optimized. The results show that by crushing ITO glass to micron size particles by HEBM, it is possible to extract higher amount of indium at room temperature than that by conventional methods using only conventional shredding machines. In this study, 86% of indium which exists in raw materials was recovered about in a very short time. © 2012 Elsevier Ltd.
Thermoelectric properties of n-type Bi2Te3 alloys produced by a combined process of magnetic pulsed compaction (MPC) and spark plasma sintering (SPS)
(2014-01-01) Lee C.; Fatih Kilicaslan M.; Madavali B.; Hong S.
In this study, n-type 95 %Bi2Te3-5 %Bi 2Se3 thermoelectric materials have been produced by a combined process of gas atomization with subsequent magnetic pulsed compaction and spark plasma sintering, and then we investigated the behavior of transport properties with sintering temperature. The microstructural observation was performed by optical microscopy and scanning electron microscopy. The crystal structures were analyzed by X-ray diffractometer. The mechanical properties were calculated by measuring the density and micro-Vickers hardness of the samples. It was found that with increasing sintering temperature the gaps between powder particles decreases and the grain sizes were coarsened. The mechanical properties shows higher values along the parallel direction compared to the perpendicular direction to the pressing. The transport properties of the thermoelectric material were investigated with variation of the sintering temperatures. The maximum power factor 1.7 × 10-3 Wm -1 K-2 was measured at the sintering temperature of 450 °C. © 2014 Springer Science+Business Media Dordrecht.