Search for dissertations about: "alloy degradation"

Showing result 1 - 5 of 47 swedish dissertations containing the words alloy degradation.

2. 1. Co-firing complex biomass in a CFB boiler : ash transformation, corrosion control and materials selection

   Author : Henrik Hagman; Dan Boström; Rainer Backman; Mats Lundberg; Lars-Erik Åmand; Umeå universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ash transformation; process control; equilibrium calculations; boiler availability; failures; alloy selection; alloy degradation; vortex finder VF ; service life estimation; sulfation; chloridation; high temperature corrosion; biomass; waste derived fuels; forest residues; RDF; Biomal; slaughterhouse waste; peat; waste wood; industrial waste water treatment sludge; HAD; RSMT; Alloy 253MA; Alloy 310S; Alloy 800H HT; Alloy DS; Alloy 600;

   Abstract : The effects of greenhouse gas net emissions on global warming, stricter legislation on waste handling, and the pursuit of ever cheaper heat- and power production are all important factors driving the introduction of complex fuels in incineration plants. However - without fundamental knowledge regarding ash transformation, corrosion control, and materials selection – this introduction of potentially economically and environmentally beneficial fuels, might instead cause economic loss and environmentally adverse effects. READ MORE

4. 2. Powder degradation during powder bed fusion processing

   Author : Ahmad Raza; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser-based powder bed fusion; Alloy 718; Powder degradation; Oxidation; Electron beam powder bed fusion; Additive manufacturing; AlSi10Mg; Residual oxygen; Spatter particles; Sublimation.;

   Abstract : Powder bed fusion (PBF) techniques, including laser-based powder bed fusion (LB-PBF) and electron beam powder bed fusion (EB-PBF), are two rapidly growing additive manufacturing (AM) processes due to their ability to produce complex geometries in near-net shapes. To attain reproducibility and repeatability in PBF processes, a consistent set of powder properties is vital. READ MORE

5. 3. Powder degradation during powder bed fusion processing: impact of processing conditions and alloy composition

   Author : Ahmad Raza; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; residual oxygen; powder bed fusion – electron beam; powder degradation; oxidation; Alloy 718; AlSi10Mg; powder bed fusion - laser beam; TiAl6V4; Hastelloy X.; sublimation; spatter particles; Keywords: additive manufacturing;

   Abstract : In the recent decade, powder bed fusion (PBF) metal additive manufacturing (AM) has attracted huge attention both from the industry and the research community. This effort has helped mature PBF technology as a potential alternative to conventional manufacturing processes as casting, machining, forging, etc. READ MORE

6. 4. ELECTRON BEAM MELTING OF ALLOY 718 - POWDER RECYCLING AND ITS EFFECT ON DEFECT FORMATION

   Author : Hans Gruber; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; powder recycling; electron beam melting; oxide defects; Alloy 718; defect formation; powder degradation; additive manufacturing; non-metallic inclusions;

   Abstract : As for any production process, the performance of additively manufactured components is ultimately dependent on the quality of the feedstock material. Consequently, for critical components, the feedstock needs to be carefully controlled to assure a stable and reliable quality. READ MORE

7. 5. On Gas Contaminants, and Bipolar Plates in Proton Exchange Membrane Fuel Cells

   Author : Yasna Acevedo Gomez; Carina Lagergren; Göran Lindbergh; Rakel Wreland Lindström; Qinfeng Li; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PEM fuel cell; contaminants; ammonia; nitrogen dioxide; degradation; recovery; bipolar plates; electroplating; Ni-Mo; Ni-Mo-P; internal contact resistance; PEM bränslecell; föroreningar; ammoniak; kvävedioxid; degradering; återhämtning; bipolära plattor; elektroplätering; Ni-Mo; Ni-Mo-P; interna kontaktmotståndet; Chemical Engineering; Kemiteknik;

   Abstract : The proton exchange membrane (PEM) fuel cell is an electrochemical device that converts chemical energy into electrical energy through two electrocatalytic reactions. The most common catalyst used is platinum on carbon (Pt/C), which has shown the best performance in the fuel cell until now. READ MORE