Kalay, İlkay
Loading...
Profile URL
Name Variants
Kalay, I.
Kalay, I
Kalay, İlkay
Kalay, Ilkay
Kalay, İlkay
Kalay, İlkay
Kalay, İlkay
Kalay, I
Kalay, İlkay
Kalay, Ilkay
Kalay, İlkay
Kalay, İlkay
Kalay, İlkay
Job Title
Dr. Öğr. Üyesi
Email Address
ikalay@cankaya.edu.tr
Main Affiliation
06.08. Mekatronik Mühendisliği
06. Mühendislik Fakültesi
01. Çankaya Üniversitesi
06.08. Mekatronik Mühendisliği
Mekatronik Mühendisliği
06. Mühendislik Fakültesi
01. Çankaya Üniversitesi
06. Mühendislik Fakültesi
01. Çankaya Üniversitesi
06.08. Mekatronik Mühendisliği
Mekatronik Mühendisliği
06. Mühendislik Fakültesi
01. Çankaya Üniversitesi
Status
Current Staff
Website
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Files
Sustainable Development Goals
SDG data is not available
This researcher does not have a Scopus ID.
This researcher does not have a WoS ID.
Scholarly Output
15
Articles
14
Views / Downloads
666/9
Supervised MSc Theses
0
Supervised PhD Theses
0
WoS Citation Count
153
Scopus Citation Count
344
WoS h-index
7
Scopus h-index
7
Patents
0
Projects
0
WoS Citations per Publication
10.20
Scopus Citations per Publication
22.93
Open Access Source
3
Supervised Theses
0
Google Analytics Visitor Traffic
| Journal | Count |
|---|---|
| Metallurgical and Materials Transactions A | 5 |
| Materials Science and Engineering: A | 2 |
| Intermetallics | 1 |
| Journal of Alloys and Compounds | 1 |
| Metallurgical And Materials Transactions A-Physical Metallurgy And Materials Science | 1 |
Current Page: 1 / 2
Scopus Quartile Distribution
Competency Cloud
15 results
Scholarly Output Search Results
Now showing 1 - 10 of 15
Correction The Anomalous Nucleation in Al-Tb Metallic Glasses (Vol 52a, Pg 700, 2021)(Springer, 2021) Ulucan, T. H.; Kalay, I.; Kalay, Y. E.Article Citation - WoS: 8Citation - Scopus: 9Effect of Sm on Thermal and Mechanical Properties of Cu-Zr Bulk Metallic Glasses(Elsevier Science Sa, 2019) Sikan, F.; Atabay, S. E.; Motallebzadeh, A.; Ozerinc, S.; Kalay, I.; Kalay, Y. E.The effect of rare-earth (Sm) microalloying on the thermal stability and phase selection along with the effect of nanocrystallization on the mechanical properties of amorphous melt-spun ribbons of Zr50Cu40Al10, Zr49Cu39.2Al9.8Sm2 and Zr48Cu38.4Al9.6Sm4 alloys were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD), transmission electron microscopy (TEM), Vickers and nanoindentation hardness tests and micropillar compression analysis. XRD and TEM analyses showed that all samples were fully amorphous in as-spun state; however, crystallization sequences for the Sm-free and the Sm micro-alloyed samples were different during devitrification. Combined study of XRD, DSC and TEM on melt-spun ribbons show that Zr48Cu38.4Al9.6Sm4 have nanocrystallization of Cu2Sm phase with an average diameter of 10 nm, which was absent in Zr50Cu40Al10, prior to crystallization of Cu10Zr7 phase. The nanoindentation and micropillar compression tests revealed Cu2Sm nanocrystals embedded in Zr48Cu38.4Al9.6Sm4 alloy improves strength and hardness. On the other hand, presence of these nanocrystals deteriorate shear band stability and thus result in a catastrophic brittle fracture through a single shear band burst.Article Kinetics and mechanisms of isothermal devitrification inamorphous cu50zr50(Springer, 2015) Cullinan, Tim; Kalay, İlkay; Kalay, Y. Eren; Kramer, Matt; Napolitano, RalphThe crystallization kinetics and microstructural dynamics associated with devitrifying a melt-spun Cu50Zr50 metallic glass were investigated using isothermal treatments, in situ high-energy synchrotron X-ray diffraction, conventional and high-resolution transmission electron microscopy, and differential scanning calorimetry. The analysis of isothermal transformations allows us to more clearly unravel the complex interplay between nucleation and growth of competing stable and metastable phases. The isothermal devitrification response was found to involve the Cu10Zr7, CuZr2, and CuZr phases, consistent with previously reported constant heating rate experiments, but here we have resolved the phase evolution and structural characteristics of the transformation, including the very early stages of crystallization. At 671 K (398 A degrees C), the isothermal transformation starts with the formation of the Cu10Zr7 phase, which grows in a generally equiaxed morphology. At a size of approximately 100 nm, the growth of the Cu10Zr7 particles is interrupted by the precipitation of a thin layer of the CuZr2 phase, upon which the metastable CuZr (B2) grows epitaxially. Crystallization kinetics are quantified here though in situ measurements (HEXRD, DSC) and ex situ microstructural analysis (TEM, HRTEM). Finally, the influences of chemical partitioning, diffusion, and crystallographic orientation on this sequence are examined.Article Citation - WoS: 11Citation - Scopus: 14Nanocrystallization in Cu-Zr Bulk Metallic Glasses(Springer, 2018) Yasar, Bengisu; Kalay, Ilkay; Sikan, FatihThe effect of rare-earth element (Sm) microalloying on the thermal stability and crystallization kinetics of melt-spun ribbons and suction-cast rods of Zr48Cu38.4Al9.6Sm4 alloy were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD), transmission electron microscopy (TEM), and atom probe tomography (APT). The XRD results of constant heating rate annealing indicated that amorphous Zr48Cu38.4Al9.6Sm4 melt-spun ribbons devitrifies into Cu2Sm at 673 K (400 A degrees C). The sequence continues with the precipitation of Cu10Zr7 and then these two phases coexist. XRD and TEM studies on 1 mm diameter as suction-cast rods indicated the precipitation of 30-nm-mean size Cu2Sm crystals during solidification. TEM investigation of the isothermal crystallization sequence of melt-spun ribbons and 1-mm-diameter suction-cast rods revealed the precipitation of Cu2Sm nanocrystals at the onset of crystallization and the restriction of the growth of these nanocrystals up to 10 nm diameter with further annealing. APT analysis of 1-mm-diameter suction-cast rods showed that the limited growth of Cu2Sm nanocrystals is due to sluggish diffusion of Sm and Al-Zr pile up at the interface.Article Citation - WoS: 25Citation - Scopus: 27Crystallization Kinetics and Phase Transformation Mechanisms in Cu56zr44 Glassy Alloy(Springer, 2015) Kramer, Matthew J.; Napolitano, Ralph E.; Kalay, IlkayThe kinetics and phase selection mechanisms involved in the crystallization of an amorphous Cu-Zr alloy of eutectic composition (Cu56Zr44) were investigated using in situ high-energy X-ray diffraction (HEXRD), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) under isothermal and constant heating rate conditions. In situ HEXRD results for 10 K/min (10 A degrees C/min) heating indicate that the amorphous alloy devitrifies into CuZr2 and mainly Cu10Zr7 at the crystallization temperature of 725 K (452 A degrees C). The sequence continues with the precipitation of CuZr (B2) at 1004 K (731 A degrees C), where these three phases coexist until the decomposition of CuZr2 is observed at 1030 K (757 A degrees C). The two equilibrium phases Cu10Zr7 and CuZr (B2) remain present on further heating until melting at the eutectic temperature for the Cu56Zr44 alloy. TEM investigation of the isothermal [705 K (432 A degrees C)] crystallization sequence reveals primary nucleation and growth of the Cu10Zr7 phase, where growth of the Cu10Zr7 crystals is initially planar with a transition to a cellular morphology, associated with partitioning of Zr at the growth front. Related cellular structures and composition profiles are quantified. (C) The Minerals, Metals & Materials Society and ASM International 2015Article Citation - WoS: 3Citation - Scopus: 3Nanomechanical Properties of Al-Tb Marginal Metallic Glass(Elsevier Science Sa, 2023) Okuyucu, Can; Ulucan, Tolga Han; Abboud, Mohammad; Motallebzadeh, Amir; Ozerinc, Sezer; Kalay, Ilkay; Kalay, Yunus ErenAl-Rare Earth (RE) metallic glasses provide an effective model system to study the effect of nanocrystallites in an amorphous matrix on nanomechanical behavior. In this work, we achieved a series of Al-Tb metallic glasscrystalline composites with systematically varying crystalline content through annealing. The nanomechanical properties were characterized using micropillar compression tests and nanoindentation for as-quenched amorphous and annealed amorphous/nanocrystalline composite specimens. The promising hardness increases after annealing from 3.0 GPa to 4.6 GPa and elastic modulus increment from 68 GPa to 92 GPa were discussed in detail, considering the structural features of Al-RE marginal metallic glass formers. The increase in elastic modulus is associated with the nucleated fcc-Al nanocrystals that divide the amorphous matrix, leading to the branching of the shear bands. The correlation between the fcc-Al nanocrystals and the behavior of shear bands was discussed in detail.Article Crack Propagation and Shear Band Evolution in Marginal AL-RE Metallic Glasses(Elsevier Ltd, 2025) Acun, Elif; Sun, Fan; Kalay, Ilkay; Berger, Marie-Helene; Kalay, Yunus ErenAluminum-rare earth marginal metallic glasses (MMGs) exhibit unique devitrification behavior, with an exceptionally high density of face-centered cubic (fcc) Al nanocrystals after the first crystallization reaction. The origin of these highly populated fcc-Al nanocrystals has been linked to a possible medium-range order (MRO) that exists within the as-quenched MMGs. However, the formation and propagation of shear bands in these MRO containing marginally glassy metallic alloys have not been thoroughly investigated and remain an open question. In this respect, we have investigated the shear band propagation using in-situ tensile straining within a transmission electron microscope (TEM). The results reveal that deformation-induced nanocrystallization occurs within shear bands, with fcc-Al nanocrystals forming in the adiabatic heat-affected zone as the crack propagates. TEM analysis indicates that nanocrystals with an average size of 5 nm form at shear bands before final fracture, providing enhanced crack deflection and energy dissipation. In that sense, MRO within the amorphous structure is believed to act as precursors, enabling the rapid formation of these fcc-Al nanocrystals under mechanical loading. Additionally, it has been shown that MRO causes heterogeneous mechanical responses, leading to variations in shear resistance within the glassy matrix. These variations contribute to the redirection, branching, and blunting as they encounter MRO embedded regions with differing local stiffness and energy dissipation capacity. © 2025 Elsevier B.V., All rights reserved.Article Citation - WoS: 4Citation - Scopus: 3Microstructure and Mechanical Properties of Al-Co High Entropy Alloys(Taylor & Francis Ltd, 2022) Ayrenk, A.; Kalay, IThe structure and mechanical properties of non-equiatomic Al8Co30Cr18Fe9Ni31Nb4, Al8Co30Cr18Fe9Ni31Nb2Ti2 and Al8Co30Cr18Fe9Ni31Ti4 high entropy alloys (HEAs) were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), hardness and tensile testing. TEM and XRD analyses revealed the formation of gamma''-Ni3Nb/gamma (FCC), double FCC and gamma'-Ni3Al/gamma (FCC) structure for as-cast Al8Co30Cr18Fe9Ni31Nb4, Al8Co30Cr18Fe9Ni31Nb2Ti2 and Al8Co30Cr18Fe9Ni31Ti4 HEAs, respectively. The hardness and yield strength values were found to increase with the addition of Nb while the ductility of alloys increased with the increase in Ti concentration, significantly. The as-cast Al8Co30Cr18Fe9Ni31Ti4 alloy exhibited an excellent combination of ultimate tensile strength of 844 MPa and an elongation of 29.8% due to the coherent phase relation between gamma' precipitates and gamma matrix. The fractured surfaces of as-cast Al8Co30Cr18Fe9Ni31Nb4, Al8Co30Cr18Fe9Ni31Nb2Ti2 and Al8Co30Cr18Fe9Ni31Ti4 HEAs showed typical dimple type ductile fracture under tension test.Article Citation - WoS: 50Citation - Scopus: 51Local Chemical and Topological Order in Al-Tb and Its Role in Controlling Nanocrystal Formation(Pergamon-elsevier Science Ltd, 2012) Kalay, Y. E.; Kalay, I.; Hwang, Jinwoo; Voyles, P. M.; Kramer, M. J.How the chemical and topological short- to medium-range order develops in Al-Tb glass and its ultimate effect on the control of the high number density of face-centered-cubic-Al (fcc-Al) nuclei during devitrification are described. A combined study using high-energy X-ray diffraction (HEXRD), atom probe tomography (APT), transmission electron microscopy and fluctuation electron microscopy (FEM) was conducted in order to resolve the local structure in amorphous Al90Tb10. Reverse Monte Carlo simulations and Voronoi tessellation analysis based on HEXRD experiments revealed a high coordination of Al around Tb atoms in both liquid and amorphous states. APT results show Al-rich and Al-depleted regions within the as-quenched alloy. A network structure of Tb-rich clusters divides the matrix into nanoscale regions where Al-rich clusters are isolated. It is this finely divided network which allows the amorphous structure to form. Al-rich regions are the locus for fcc-Al crystallization, which occurs before the intermetallic crystallization. FEM reveals medium-range ordered regions similar to 2 nm in diameter, consistent with fcc-Al and trigonal-like Al3Tb crystal structures. We propose that the high coordination of Al around Tb limits diffusion in the intermetallic network, allowing for the isolated Al-rich regions to form at high density. These regions are responsible for the extremely high density of Al nanocrystal nuclei. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.Article Citation - WoS: 23Citation - Scopus: 24Kinetics and Mechanisms of Isothermal Devitrification in Amorphous Cu50zr50(Springer, 2015) Kalay, Ilkay; Kalay, Y. Eren; Kramer, Matt; Napolitano, Ralph; Cullinan, TimThe crystallization kinetics and microstructural dynamics associated with devitrifying a melt-spun Cu50Zr50 metallic glass were investigated using isothermal treatments, in situ high-energy synchrotron X-ray diffraction, conventional and high-resolution transmission electron microscopy, and differential scanning calorimetry. The analysis of isothermal transformations allows us to more clearly unravel the complex interplay between nucleation and growth of competing stable and metastable phases. The isothermal devitrification response was found to involve the Cu10Zr7, CuZr2, and CuZr phases, consistent with previously reported constant heating rate experiments, but here we have resolved the phase evolution and structural characteristics of the transformation, including the very early stages of crystallization. At 671 K (398 A degrees C), the isothermal transformation starts with the formation of the Cu10Zr7 phase, which grows in a generally equiaxed morphology. At a size of approximately 100 nm, the growth of the Cu10Zr7 particles is interrupted by the precipitation of a thin layer of the CuZr2 phase, upon which the metastable CuZr (B2) grows epitaxially. Crystallization kinetics are quantified here though in situ measurements (HEXRD, DSC) and ex situ microstructural analysis (TEM, HRTEM). Finally, the influences of chemical partitioning, diffusion, and crystallographic orientation on this sequence are examined.
