Search for dissertations about: "grain boundaries"

Showing result 11 - 15 of 199 swedish dissertations containing the words grain boundaries.

2. 11. Computational modeling of oxygen-assisted fracture in nickel-based superalloys

   Author : Kim Louisa Auth; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stress-assisted diffusion; Intergranular fracture; Crack growth rate; Crystal plasticity; Moving boundary condition.; Crack propagation; Grain boundaries; Polycrystal;

   Abstract : Nickel-based superalloys are a commonly used material in applications where high strength is required at high temperatures. A typical such example is jet engines and, in the case of polycrystalline nickel-based superalloys, components like turbine disks. READ MORE

4. 12. Silicon Carbide Reinforced Alumina and Mullite Ceramics

   Author : Stefan Gustafsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ceramic Nanocomposites; Creep; SEM; SiC; Grain Boundaries; Microanalysis; Mullite; Pressureless Sintering; TEM; Alumina;

   Abstract : The aim of this work was to develop homogeneous ceramic nanocomposite materials with good thermal and structural stability as well as good mechanical properties. The development of microstructure was related to the material properties. READ MORE

5. 13. Acceptor-doped barium zirconate: Oxidation, hydration and space-charge formation

   Author : Anders Lindman; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; BaZrO3; space charge; point defects; oxidation; GW; hydration; density functional theory; grain boundaries; interatomic potential; perovskites;

   Abstract : The current production and use of fossil fuels is not sustainable and new technologies are needed to become more independent of these fuels.The hydrogen economy, with the fuel cell as an efficient converter of chemical to electrical energy, is a desirable alternative.For this to become a reality, new materials with tailored properties are required. READ MORE

6. 14. On the defective origin of conductive and structural properties of oxides: insights from first principles

   Author : Anders Lindman; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; point defects; thermodynamic modeling; proton conductors; oxyhydrides; density-functional theory; BaZrO3; polarons; grain boundaries; space charges; oxides;

   Abstract : Oxides are versatile materials with applications in many different research fields; especially those related to clean energy technologies, such as fuel cells, batteries and solar panels. Many functional properties of these materials derive from lattice imperfections, or defects, and a lot of effort has been put into fine tuning these materials by modifying their structure on the atomic scale. READ MORE

7. 15. Theory of electron transport in superconducting heterostructures

   Author : Magnus Hurd; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-Tc; superconducting junctions; transport processes; heterostructures; BCS theory; Ginzburg-Landau theory; superconductors; Josephson effect; critical currents; grain boundaries; superconductivity;

   Abstract : .... READ MORE