Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article 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 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.