Development of Nanostructured Metallic Glasses with High Toughness

Bagheri Behboud, Ali
Metallic glasses are metallic alloys with disordered atomic structures and desirable mechanical properties such as high hardness, high elastic limits, and wear resistance. These properties make metallic glasses promising materials for wear-resistant, corrosion-resistant, and biocompatible coating applications. On the other hand, metallic glasses are brittle, which is a major disadvantage for their use in practice. This thesis study aimed to tackle this problem through the development of nanostructured metallic glasses with high toughness and ductility. In the first part, the thesis considered synthesizing a binary thin film metallic glass over a wide compositional range. Two binary systems, namely, ZrTa and CuTa were investigated. Physical vapor deposition method was the approach for producing the thin films samples, and a combinatorial sputtering technique was employed during the deposition process. This way, 25 monolithic samples (13 ZrTa and 12 CuTa samples) were produced in only two sputtering sessions. The microstructures of the alloy systems were then investigated, demonstrating a wide compositional range of amorphous structures in both systems. Combining these with micromechanical testing provided the underlying structure-property relationships. The next step was the exploration of a novel approach for overcoming the brittle nature of metallic glasses through engineered heterogeneities in the form of compositional modulations. A recently developed indentation-based energy method was used to determine the fracture toughness of nanolayered ZrTa samples, and the results demonstrated that the nanolayered metallic glass composites combine high hardness with ductility, rendering this approach promising for the development of commercial coatings for engineering applications. The same route was also explored CuTa system. In this case, a more sophisticated technique was used to measure the ductility through direct tensile testing. The results showed that the nanolayered metallic glass and MG-crystalline composites combine high hardness, elastic modulus, and ductility, demonstrating their great potential to develop high performance composite coatings.


Micromechanical characterization of metallic glass — crystalline nanocomposite coatings
Abboud, Mohammad; Özerinç, Sezer; Kalay, Yunus Eren; Department of Micro and Nanotechnology (2018)
Amorphous/crystalline nanolayers provide an effective model system to study the mechanical behavior and size effects of metallic glasses and crystalline metals in confined geometries. They also provide an advantageous structure for improving the ductility of amorphous metals while maintaining their outstanding strength. Combination of high strength and ductility make these nanocomposites promising materials as wear resistant coatings. The structure-property relationship in Amorphous/Crystalline nanolayers c...
Magnetic monitoring approach to nanocrystallization kinetics in Fe-based bulk amorphous alloy
Duman, Nagehan; Akdeniz, Mahmut Vedat; Mehrabov, Amdulla (2013-12-01)
Much of the recent metallic glass research is devoted to controlling the crystallization of amorphous precursors with the purpose of obtaining amorphous matrix nanocrystalline alloys which combine unmatched soft magnetic properties with good mechanical properties. Therefore, it is crucial to have better understanding of crystallization mechanisms and thermal dependence of nanocrystals that are formed by annealing. This study deals with the nanociystallization kinetics of Cu-modified Fe-Co-Ni-B-Si-Nb bulk am...
Investigation of material properties of magnetron sputtered CuAg-In-Se thin films
Güllü, Hasan Hüseyin; Parlak, Mehmet (null; 2016-09-23)
Thin films of copper based chalcopyrite absorber materials are attracting the attention of many researchers because of their favorable optoelectronic properties and good stability makes them suitable for photovoltaic and optoelectronic device applications. These compounds are particularly suitable for making p-n hetero-junctions with the II-VI compounds. Therefore, the utilization of I-III-VI2 group of chalcopyrite semiconductors has been reported in the literature for application in thin film solar cells. ...
Nanoheterogeneous ZrTa metallic glass thin films with high strength and toughness
Behboud, Ali B.; Motallebzadeh, Amir; Özerinç, Sezer (2022-04-25)
This study investigated the mechanical behavior of ZrxTa1−x (x = 21–79 at%) thin films and nanolayered films of ZrTa with modulated composition as model systems to gain insight into the hardness and toughness of metallic glasses and metallic glass nanocomposites. The monolithic films exhibit two primary microstructures, namely, a fully amorphous form (Zr = 35–70at%.) and an amorphous-crystalline composite (21–30 at% Zr). The amorphous films show a monotonic hardness variation with composition over a wide ra...
Synthesis and Characterization of Zirconium based Bulk Amorphous Alloys
Saltoğlu, İlkay; Akdeniz, Mahmut Vedat; Mehrabov, Amdulla (2005-09-28)
In recent years, bulk amorphous alloys and nanocrystalline materials have been synthesized in a number of ferrous and non-ferrous based alloys systems, which have gained some applications due to their unique physico-chemical and mechanical properties. In the last decade, Zr-based alloys with a wide supercooled liquid region and excellent glass forming ability have been discovered. These systems have promising application fields due to their mechanical properties; high tensile strength, high fracture toughne...
Citation Formats
A. Bagheri Behboud, “Development of Nanostructured Metallic Glasses with High Toughness,” M.S. - Master of Science, Middle East Technical University, 2021.