Download or read book High Cycle Fatigue of Al and Cu Thin Films by a Novel High Throughput Method written by Sofie Burger and published by KIT Scientific Publishing. This book was released on 2014-05-19 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last two decades, the reliability of small electronic devices used in automotive or consumer electronics gained researchers attention. Thus, there is the need to understand the fatigue properties and damage mechanisms of thin films. In this thesis a novel high-throughput testing method for thin films on Si substrate is presented. The specialty of this method is to test one sample at different strain amplitudes at the same time and measure an entire lifetime curve with only one experiment.
Download or read book A novel micro mechanical model for prediction of multiaxial high cycle fatigue at small scales written by Eslami, Reza and published by KIT Scientific Publishing. This book was released on 2017-05-03 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The grain microstructure and damage mechanisms at the grain level are the key factors that influence fatigue of metals at small scales. This is addressed in this work by establishing a new micro-mechanical model for prediction of multiaxial high cycle fatigue (HCF) at a length scale of 5-100?m. The HCF model considers elasto-plastic behavior of metals at the grain level and microstructural parameters, specifically the grain size and the grain orientation.
Download or read book Microplasticity of idealized single crystalline Ag cantilevers characterized with methods of high resolution written by Wobrock, Mark and published by KIT Scientific Publishing. This book was released on 2017-11-22 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single crystalline, μm-sized cantilevers are fabricated out of epitaxially grown Ag thin films by a lithography-based procedure and are deflected by a nanoindenter system. The microstructure of the plastically deformed cantile-vers is investigated using transmission Kikuchi diffraction (TKD) on the cantilever cross section. 3D discrete dislocation dynamics simulations (DDD) are performed for further analysis. A mechanism to explain the formation of dislocation networks upon loading is suggested.
Download or read book Experimental Investigation of Crack Initiation in Face Centered Cubic Materials in the High and Very High Cycle Fatigue Regime written by Straub, Thomas and published by KIT Scientific Publishing. This book was released on 2016 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book investigates the fatigue mechanisms and crack initiation of Ni, Al and Cu on a small-scale in the Very High Cycle Fatigue regime by means of innovative fatigue experimentation. A novel custom-built resonant fatigue setup showed that the sample resonant frequency changes with increasing cycle number due to fatigue damage. Mechanisms such as slip band formation have been observed. Cyclic hardening, vacancy and oxidation formation may be considered as early fatigue mechanisms.
Download or read book Influence of strain on the functionality of ink jet printed thin films and devices on flexible substrates written by Mishra, Nilesha and published by KIT Scientific Publishing. This book was released on 2019-02-15 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ink-jet printed devices on the flexible substrate are inexpensive and large area compatible as compared to rigid substrates. However, during fabrication and service they are subjected to complex strains, resulting in crack formation or delamination within the layers, affecting the device performance. Therefore, it is necessary to understand their failure mechanisms by correlating their electrical or structural properties with applied strain, supported by detailed microstructural investigations.
Download or read book Fatigue of Micro Molded Materials Aluminum Bronze and Yttria Stabilized Zirconia written by Kennerknecht, Tobias and published by KIT Scientific Publishing. This book was released on 2014-12-04 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Custom built setups were developed to investigate micro samples during quasistatic and cyclic testing in tension, compression and bending. Micro molded CuAl10Ni5Fe4-samples showed similar fatigue behavior compared to macroscopic samples due to both the sample size and microstructure being scaled down with the manufacturing process. Results from cyclic three-point bending tests on micro molded 3Y-TZP suggested that a minimum crack extension is necessary to develop cyclically degradable shielding.
Download or read book Fluid Flow and Heat Transfer in Cellular Solids written by Ettrich, Joerg and published by KIT Scientific Publishing. This book was released on 2014-09-26 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: To determine the characteristics and properties of cellular solids for an application, and to allow a systematic practical use by means of correlations and modelling approaches, we perform experimental investigations and develop numerical methods. In view of coupled multi-physics simulations, we employ the phase-field method. Finally, the applicability is demonstrated exemplarily for open-cell metal foams, providing qualitative and quantitative comparison with experimental data.
Download or read book Modeling transport properties and electrochemical performance of hierarchically structured lithium ion battery cathodes using resistor networks and mathematical half cell models written by Birkholz, Oleg and published by KIT Scientific Publishing. This book was released on 2022-10-05 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hierarchically structured active materials in electrodes of lithium-ion cells are promising candidates for increasing gravimetric energy density and improving rate capability of the system. To investigate the influence of cathode structures on the performance of the whole cell, efficient tools for calculating effective transport properties of granular systems are developed and their influence on the electrochemical performance is investigated in specially adapted cell models.
Download or read book Grain growth behavior and efficient large scale simulations of recrystallization with the phase field method written by Vondrous, Alexander and published by KIT Scientific Publishing. This book was released on 2014-12-15 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the found insights of grain growth behavior, of multidimensional decomposition for regular grids to efficiently parallelize computing and how to simulate recrystallization by coupling the finite element method with the phase-field method for microstructure texture analysis. The frame of the book is created by the phase-field method, which is the tool used in this work, to investigate microstructure phenomena.
Download or read book On the Electro Chemo Mechanical Coupling in Solid State Batteries and its Impact on Morphological Interface Stability written by Ganser, Markus and published by KIT Scientific Publishing. This book was released on 2021-03-09 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid state batteries with a lithium metal electrode are considered the next generation of high energy battery technology. Unfortunately, lithium metal is prone to harmful protrusion or dendrite growth which causes dangerous cell failure. Within this work the problem of protrusion growth is tackled by deriving a novel electro-chemo-mechanical theory tailored for binary solid state batteries which is then used to discuss the impact of mechanics on interface stability by numerical studies.
Download or read book Investigations on Joule heating applications by multiphysical continuum simulations in nanoscale systems written by Feuchter, Manuel Klaus Ludwig and published by KIT Scientific Publishing. This book was released on 2014-10-01 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work furthers the overall understanding of a 3w-measurement, by considering previously unexamined macroscopic influence factors within measurement by Finite Element simulations (FES). Moreover, new measuring configurations are developed to determine (an)isotropic thermal conductivities of nanoscale samples. Since no analytic solutions are available for these configurations, a new evaluation methodology is presented to determine emergent thermal conductivities by FES and Neural Networks.
Download or read book On the structure property correlation and the evolution of Nanofeatures in 12 13 5 Cr oxide dispersion strengthened ferritic steels written by He, Pei and published by KIT Scientific Publishing. This book was released on 2013-12-24 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Main objective of this work is to develop, by systematic variation of the chemical composition, and TMP, 14% Cr nano-structured ferritic alloys with significantly improved high-temperature properties compared to currently available ODS alloys. Application of state-of-the-art characterization tools shall lead to an integrated understanding of structure-property correlation and the formation mechanism of nanoparticles.
Download or read book Phase field modeling of microstructural pattern formation in alloys and geological veins written by Ankit, Kumar and published by KIT Scientific Publishing. This book was released on 2016-05-31 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advent of high performance computing, the application areas of the phase-field method, traditionally used to numerically model the phase transformation in metals and alloys, have now spanned into geoscience. A systematic investigation of the two distinct scientific problems in consideration suggest a strong influence of interfacial energy on the natural and induced pattern formation in diffusion-controlled regime.
Download or read book Dynamic Model based Analysis of Oxygen Reduction Reaction in Gas Diffusion Electrodes written by Röhe, Maximilian and published by KIT Scientific Publishing. This book was released on 2024-01-09 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the first simulation model of oxygen depolarized cathodes (ODC), which are silver catalyst-based gas diffusion electrodes, is presented that considers the phase equilibrium of the gas-liquid interface and structure-related inhomogeneities in electrolyte distribution. By means of the model it has been identified that mass transport of water and ions in the liquid phase is a crucial factor for electrode performance and how it is influenced by the electrode structure.
Download or read book Characterization and Modeling of the Ratcheting Behavior of the Ferritic Martensitic Steel P91 written by Zhang, Kuo and published by KIT Scientific Publishing. This book was released on 2017-07-12 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the ratcheting-behavior of 9%Cr-1%Mo ferritic-martensitic steel is studied with uniaxial cyclic loading. To describe the ratcheting-behavior of this steel, a visco-plastic constitutive model with consideration of cyclic softening of Reduced Activation Ferritic Martensitic steels is further modified, based on the analysis of back stress.
Download or read book The Impact of Recycling on the Fibre and the Composite Properties of Carbon Fibre Reinforced Plastics written by Hüther, Jonas Johannes and published by KIT Scientific Publishing. This book was released on 2020-06-19 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Micromechanical study on the deformation behaviour of directionally solidified NiAl Cr eutectic composites written by Kumar, Amritesh and published by KIT Scientific Publishing. This book was released on 2017-11-06 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
