Sökning: "porosity"

Visar resultat 1 - 5 av 433 avhandlingar innehållade ordet porosity.

1. 1. Fatigue strength of engineering materials : the influence of environment and porosity

   Författare :Jan Linder; Bengt Lindberg; Lennart Josefsson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stainless steel; cast aluminium; hardened steels; fatigue; corrosion; crack propagation; spot weld; porosity; Other materials science; Övrig teknisk materialvetenskap;

   Sammanfattning : The objective of this work was to use LEFM in order to assess the detrimental influence of surrounding chloride-containing environments for stainless steels, hardened steel as well as for a cast aluminium alloy. An additional aim was also to use LEFM to assess the influence of porosity on the fatigue properties for different commercial cast aluminium alloys and manufacturing methods. LÄS MER

3. 2. Laser welding of ultra-high strength steel and a cast magnesium alloy for light-weight design

   Författare :Karl Fahlström; Lars-Erik Svensson; Leif Karlsson; Michael Rethmeier; Högskolan Väst; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser welding; ultra-high strength steel; cast magnesium alloy; light-weight design; automotive industry; distortion; porosity; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

   Sammanfattning : There is a strong industrial need for developing robust and flexible manufacturing methods for future light-weight design. Better performing, environmental friendly vehicles will gain competitive strength from using light weight structures. LÄS MER

4. 3. Welding of Ti-6Al-4V: Influence of welding process and alloy composition on microstructure and properties

   Författare :Sakari Tolvanen; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fatigue; microstructure; Ti-6Al-4V; porosity; welding; defects;

   Sammanfattning : Titanium alloys are widely used for components in the fan and compressor sections of aeroengines mainly because of their superior strength-to-weight ratio. Large static compressor components can be manufactured by welding together smaller subcomponents, which has potential to provide benefits such as higher buy-to-fly ratio and improved performance of the components. LÄS MER

5. 4. Analysis of Deformation of Gas Diffusion Layers and the Impact on Performance of PEM Fuel Cells

   Författare :Jiatang Wang; Värmeöverföring; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PEM fuel cell; compression ratio; assembly pressure; porosity; deformed GDL; electric resistance; transport phenomena; model; performance; analysis; OpenFOAM;

   Sammanfattning : Proton exchange membrane (PEM) fuel cells have been promoted due to significant breakthroughs in various aspects and increasing public interests. The porous features of the gas diffusion layer (GDL) and the necessary assembly processes generate localized pressure forces on the channel/shoulder structure of the bi-polar plates (BPP). LÄS MER

7. 5. Increased Productivity of Ferrous Alloys Produced by Powder Bed Fusion - Laser Beam

   Författare :Rasmus Gunnerek; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; additive manufacturing; process optimization; build rate; build speed; powder bed fusion – laser beam; porosity; low alloy steel; 316L stainless steel; productivity in AM;

   Sammanfattning : Low production speeds limit wider adoption of powder bed fusion – laser beam (PBF-LB) in cost sensitive industries as it correlates directly with high production costs. The main process parameters such as scan speed, hatch distance and layer thickness can be scaled up to increase build speed, but it often comes at a trade off in lower quality, i. LÄS MER