Search for dissertations about: "Dislocations"

Showing result 1 - 5 of 137 swedish dissertations containing the word Dislocations.

2. 1. Dislocations in silicon

   Author : Niklas Lehto; Luleå tekniska universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fysik; Fysik;

   Abstract : The topic of this thesis is theoretical studies of the electrical and structural properties in the elemental semiconductor silicon. Because of the numerous and powerful applications of semiconductors, e.g., rectifiers, transistors, solar cells and lasers, they have been the focus of huge amounts of research. READ MORE

4. 2. Numerical Modeling of Plasticity in FCC Crystalline Materials Using Discrete Dislocation Dynamics

   Author : Arash Hosseinzadeh Delandar; Pavel Korzhavyi; Rolf Sandström; Mikko Alava; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dislocations; crystal plasticity; discrete dislocation dynamics; Cu single crystal; high strain rate deformation; strain rate sensitivity; plastic anisotropy; slip band formation; Teknisk materialvetenskap; Materials Science and Engineering;

   Abstract : Plasticity in crystalline solids is controlled by the microscopic line defects known as “dislocations”. Decisive role of dislocations in crystal plasticity in addition to fundamentals of plastic deformation are presented in the current thesis work. READ MORE

5. 3. Modelling and simulation of short fatigue cracks

   Author : Christina Bjerkén; Materialteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; materialteknik; Materiallära; Material technology; Interface cracks; Dislocations; Short cracks; Local plasticity;

   Abstract : The growth of short fatigue cracks deviates from the behaviour of long fatigue cracks even if subjected to the same nominal driving force. The influence from the microstructure is pronounced, while crack closure effects may not be that important as for longer cracks. READ MORE

6. 4. Microstructural Decay in High-Strength Bearing Steels under Rolling Contact Fatigue

   Author : Tania Loaiza; Peter Hedström; Mårten Olsson; Steve Ooi; Prasath Babu; Harry Bhadeshia; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microstructural decay; microscopy; rolling contact fatigue; Hybrid 60 steel; Bearing steel; 52100; dislocations; ferrite microbands; Mikrostrukturell nedbrytning; mikroskopi; rullande kontaktfatigue; Hybrid 60-stål; dislokationer; Materials Science and Engineering; Teknisk materialvetenskap;

   Abstract : The work presented in this thesis aims to enhance our understanding of material decay in high-strength steels used for bearing applications. The primary objective is to investigate the microstructural changes in two high-strength steels: 52100 steels, a popular bearing steel, and Hybrid 60, a relatively new bearing steel designed for long fatigue life and use at elevated temperatures. READ MORE

7. 5. Creep Behaviour of Titanium Aluminides and its Relation to Phase Distributions and Dislocation Structures

   Author : Dennis Lundström; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gamma-TiAl; twinning; fatigue; dislocations; microstructure; thermal transport properties; creep;

   Abstract : The need for more efficient gas turbines with lowered fuel consumption and thereby lowered emission has recently lead to increased interest in low-density, .gamma.-based TiAl intermetallic alloys as a replacement of e.g. READ MORE