Browsing by Author "Kilicaslan M.F."

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Depth sensing indentation analyses of hypereutectic Al-10Ni — XSc (X = 0, 1, 2) alloys
(2017-05-01) Kilicaslan M.F.; Karakose E.
Depth sensing indentation analyses of hypereutectic Al-10Ni alloys with different amounts of Sc content were performed to determine the values of elastic modulus, dynamic microhardness, creep rate and elastic recovery rate. Microstructural characterizations were performed by using scanning electron microscopy (SEM), SEM mapping and an X-ray diffractometer. The results revealed that the addition of Sc refined the intermetallic phases of Al and Ni, and led to the formation of two additional intermetallic phases as well, namely Al3Sc and metastable Al9Ni2. The Al-Ni alloys investigated in this work exhibited elastoplastic behavior at room temperature and the addition of Sc influences their elastic-plastic responses to the indentation process. In addition, dynamic microhardness of them exhibited a load-dependent character called the indentation size effect. The addition of Sc considerably improved the values of dynamic microharddness, elastic modulus and elastic recovery rate. It also resulted in a lower creep displacement rate.
Effect of Ni Addition on the Morphology and Microstructure of Both Conventional Cast and Melt-Spun of Al–Si–Fe–Nb (at wt%) Alloy
(2019-11-01) Kilicaslan M.F.; Altaib S.S.; Vurdu C.D.
In this project the morphology and microstructure of both conventional cast and melt spun of Al–20Si–9Fe–1.2Nb and Al–20Si–9Fe–1.2Nb–6Ni (at wt%) alloys were investigated. Therefore, in order to study the effect of added Ni on the morphology characteristics of the above-mentioned alloy, the resulting conventional cast and ribbons of Al–20Si–9Fe–1.2Nb and Al–20Si–9Fe–1.2Nb–6Ni alloys were synthesized and analysed using OM optical microscopy, X-ray diffraction, SEM scanning electron microscopy together with EDS energy dispersive spectroscopy. Observations exhibit that, XRD patterns of Al–Si–Fe–Nb and Al–Si–Fe–Nb–Ni ribbons revealed the peaks of only α-Al phase. Therefore, after adding of 6 wt% Ni, peaks of α-Al were shifted to the relatively lower angles with a very weak intensity. Furthermore, 6 wt% Ni addition causes homogeneously scattered colonies (size range 5 –25 μm) which contain fine spherical (primary Si and δ-Al4(FeNiNb)Si2 phases) particles in the α-Al dendrite of rapidly solidified Al–20Si–9Fe–1.2Nb alloy, the size of spherical particles were found to be in the range of 100 nm–1 μm.
Production of CNT-bearing melt-spun Al-2Sc-0.05CNT alloys
(2018-03-25) Kilicaslan M.F.; Karaköse E.
In the present work, rapidly solidified Al–2Sc-XCNT (X = 0, 0.05) alloys were successfully fabricated by melt spinning under Ar atmosphere. The effects of addition of CNT on the microstructural, thermal, microhardness, and electrical properties were investigated by using scanning electron microscopy (SEM), X-ray diffractometer (XRD), differential calorimeter (DSC), Vickers microhardness testing and a four point probe resistivity tester. Experimental results illustrated that the addition of 0.05 wt% CNT to melt-spun Al–2Sc alloys led to the formation of equiaxed globular-like morphologies with size from 0.3 to 2.7 μm in. In the microstructure of Al-2Sc-0.05CNT alloy, CNTs covered by Al with size (width and length) changing from 40 to 55 nm and 255–295 nm, respectively, were observed. The addition of CNT led to a net increment (∼25%) in microhardness values due to solitary strengthening of the carbon nanotubes, solute solution hardening and modification of the morphologies of Al3Sc intermetallics. In addition, because of CNT addition there was a decrease in the electrical resistivity.