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Visar resultat 1 - 5 av 94 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Wear mechanisms in sheet metal forming : Effects of tool microstructure, adhesion and temperature

   Författare :Anders Gåård; Pavel Krakhmalev; Jens Bergström; Ulf Olofsson; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Galling; sheet metal forming; wear; friction; adhesion; temperature; Materialteknik; Materials Engineering;

   Sammanfattning : The general trend in the car body manufacturing industry is towards low-series production and reduction of press lubricants and car weight. The limited use of lubricants, in combination with the introduction of high and ultrahigh-strength sheet materials, continuously increases the demands on the forming tools. LÄS MER

3. 2. A study of micro-particles in the dust and melt at different stages of iron and steelmaking

   Författare :Muhammad Nabeel; Andrey Karasev; Lauri Holappa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Particle size distribution; ironmaking; iron ore pellets; dust generation; mechanical wear; friction; reduction; REM clusters; Electrolytic extraction; cluster size distribution; growth mechanism; collisions; statistical analysis.; Teknisk materialvetenskap; Materials Science and Engineering; Metallurgical process science; Metallurgisk processvetenskap;

   Sammanfattning : The dust particles generated due to mechanical wear of iron ore pellets and clusters formed in molten stainless steel alloyed with rare earth metals (REM) are considered in this study. Firstly, the influence of the characteristics of iron ore pellets, applied load on a pellet bed and partial reduction of the pellets on the size distribution of the generated dust was investigated. LÄS MER

4. 3. Microstructure and Wear of CVD Coatings used in Metal Cutting Applications

   Författare :Andreas Larsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MTCVD; Ca-treated steel; EFTEM; CVD; TEM; Ti C; alfa-Al2O3; gamma-Al2O3; wear; kappa-Al2O3; N ; EELS;

   Sammanfattning : This thesis is concerned with the microstructural characterisation of wear resistant Al2O3 and Ti(C,N)coatings produced by chemical vapour deposition on cemented carbide cutting tools. The investigation focuses on the effect of deposition conditions on the microstructure and the microstructural evolution of the coatings during heat-treatments and metal cutting. LÄS MER

5. 4. Wear reduction performance of rail flange lubrication

   Författare :Patric Waara; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

   Sammanfattning : Rail and rail wheel flange wear on the rail track has been a problem of attention for the last 30 years. The problems arise in curves and depend on increased traffic volume, heavier axle load and also higher speed. Axle loads of 22,5-25 ton is common nowadays and the trend is towards heavier axle loads where the next step is 30-35 ton. LÄS MER

7. 5. The role of head size in total hip arthroplasty - Dislocation, wear and cup stability

   Författare :Georgios Tsikandylakis; Göteborgs universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; arthroplasty; head; dislocation; wear; corrosion; cup migration;

   Sammanfattning : Large heads are used in total hip arthroplasty, with the aim of reducing the risk of dislocation, but there are concerns related to polyethylene wear, corrosion and cup loosening. Paper I is an observational study that aimed to investigate whether the transition from 28-mm to 32-mm heads and thereafter to 36-mm heads in patients undergoing total hip arthroplasty (THA) after osteoarthritis has been followed by a reduction in dislocation rates in the Nordic countries. LÄS MER