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Full-Text Articles in Materials Science and Engineering

Tailoring The Mechanical And Optical Properties Of Silicon-Niobium-Nitride Composite Coatings, Cristian Orozco Jan 2019

Tailoring The Mechanical And Optical Properties Of Silicon-Niobium-Nitride Composite Coatings, Cristian Orozco

Open Access Theses & Dissertations

Nitride nanocomposite thin films have generated significant attention as a result of their robust mechanical properties, excellent triobology, and good chemical (corrosion) stability. Due to their excellent hardness and high wear resistance NbN coatings have found use in a wide variety of applications such as the coating of cutting tools and to strengthen the surface mechanical properties of superconducting cavities. The mechanical properties of NbN can be further improved through mixing with Si3N4, leading to the formation of a nanocomposite structure. NbN-Si3N4 nanocomposite coatings have been actively studied due to their high hardness, high elastic modulus, and high resistance to …


Mechanical Properties And Degradation Of High Capacity Battery Electrodes: Fundamental Understanding And Coping Strategies, Yikai Wang Jan 2019

Mechanical Properties And Degradation Of High Capacity Battery Electrodes: Fundamental Understanding And Coping Strategies, Yikai Wang

Theses and Dissertations--Chemical and Materials Engineering

Rechargeable lithium ion and lithium (Li) metal batteries with high energy density and stability are in high demand for the development of electric vehicles and smart grids. Intensive efforts have been devoted to developing high capacity battery electrodes. However, the known high capacity electrode materials experience fast capacity fading and have limited cycle life due to electromechanical degradations, such as fracture of Si-based electrodes and dendrite growth in Li metal electrodes. A fundamental understanding of electromechanical degradation mechanisms of high capacity electrodes will provide insights into strategies for improving their electrochemical performance. Thus, this dissertation focuses on mechanical properties, microstructure …


Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe Jan 2018

Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe

Open Access Theses & Dissertations

Hafnium oxide, or hafnia, is a high temperature refractory material with good electrical, chemical, optical, and thermodynamic properties. The effects of dopants have been widely studied, especially after the discovery of ferroelectricity induced in hafnia thin films. While attractive and used in the opto-electronic, memory devices, and semiconductor industries, there is a lack in the literature on enhancing the mechanical properties of hafnium oxide, specifically through doping it with tungsten, another material of interest particularly for future high temperature device applications. Thus, this work aimed to grow hafnia thin films doped with varying amounts of tungsten. The samples were grown …


Characterization Of High-Purity Niobium Structures Fabricated Using The Electron Beam Melting Process, Cesar Adrian Terrazas Jan 2014

Characterization Of High-Purity Niobium Structures Fabricated Using The Electron Beam Melting Process, Cesar Adrian Terrazas

Open Access Theses & Dissertations

Additive Manufacturing (AM) refers to the varied set of technologies utilized for the fabrication of complex 3D components from digital data in a layer-by-layer fashion. The use of these technologies promises to revolutionize the manufacturing industry. The electron beam melting (EBM) process has been utilized for the fabrication of fully dense near-net-shape components from various metallic materials. This process, catalogued as a powder bed fusion technology, consists of the deposition of thin layers (50 - 120µm) of metallic powder particles which are fused by the use of a high energy electron beam and has been commercialized by Swedish company Arcam …