Author : Eslami, Reza
Publisher : KIT Scientific Publishing
Page : 142 pages
File Size : 45,52 MB
Release : 2017-05-03
Category : Technology (General)
ISBN : 3731505835
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.
Author : Reza Eslami
Publisher :
Page : 130 pages
File Size : 35,5 MB
Release : 2020-10-09
Category : Science
ISBN : 9781013282836
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. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.
Author : Kumar, Amritesh
Publisher : KIT Scientific Publishing
Page : 160 pages
File Size : 48,36 MB
Release : 2017-11-06
Category :
ISBN : 3731506947
Author : Zhang, Tao
Publisher : KIT Scientific Publishing
Page : 224 pages
File Size : 44,15 MB
Release : 2021-09-27
Category : Technology & Engineering
ISBN : 3731510022
Most storage materials exhibit phase changes, which cause stresses and, thus, lead to damage of the electrode particles. In this work, a phase-field model for the cathode material NaxFePO4 of Na-ion batteries is studied to understand phase changes and stress evolution. Furthermore, we study the particle size and SOC dependent miscibility gap of the nanoscale insertion materials. Finally, we introduce the nonlocal species concentration theory, and show how the nonlocality influences the results.
Author : Ganser, Markus
Publisher : KIT Scientific Publishing
Page : 272 pages
File Size : 40,31 MB
Release : 2021-03-09
Category : Technology & Engineering
ISBN : 3731510472
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.
Author : Schulz, Sebastian
Publisher : KIT Scientific Publishing
Page : 246 pages
File Size : 26,91 MB
Release : 2017-02-22
Category : Aluminum
ISBN : 3731506181
The utilization of thermodynamic and mobility data plays a major role in phase-field modeling. This work discusses different formulations for the thermodynamic quantities of a grand potential model along with practices to determine parameters from datasets. The framework is used to study solidification of Al-Si-Mg for a variation of composition, diffusivities and surface energy anisotropies. To verify the simulations, they are compared with solidification theories.
Author : Cihan, Ebru
Publisher : KIT Scientific Publishing
Page : 194 pages
File Size : 47,99 MB
Release : 2020-10-21
Category : Technology & Engineering
ISBN : 3731509997
Recent studies of deformation mechanisms of metals and alloys pioneer the better investigation of the friction and wear behavior of materials with well-defined initial microstructures. Within this scope, in this work, the effect of sub-surface deformations on the resulting friction and wear behavior has been searched by means of a systematic experimental study on Au-Ni metallic multilayer model alloy system.
Author : Röhe, Maximilian
Publisher : KIT Scientific Publishing
Page : 178 pages
File Size : 47,43 MB
Release : 2024-01-09
Category :
ISBN : 3731512343
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.
Author : Birkholz, Oleg
Publisher : KIT Scientific Publishing
Page : 246 pages
File Size : 17,2 MB
Release : 2022-10-05
Category : Science
ISBN : 373151172X
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.
Author : Wobrock, Mark
Publisher : KIT Scientific Publishing
Page : 252 pages
File Size : 28,98 MB
Release : 2017-11-22
Category : Diffraction
ISBN : 3731506823
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.
