Sökning: "powder degradation"

Visar resultat 1 - 5 av 27 avhandlingar innehållade orden powder degradation.

  1. 1. Powder degradation during powder bed fusion processing

    Författare :Ahmad Raza; Chalmers tekniska högskola; []
    Nyckelord :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.;

    Sammanfattning : 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. LÄS MER

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

    Författare :Ahmad Raza; Chalmers tekniska högskola; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 3. Degradation of polyethylene pipes distributing chlorinated water : depletion of stabilizers, release of degraded products and polymer degradation

    Författare :Wenbin Yu; Ulf Gedde; Mats Jonsson; Minna Hakkarainen; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polyethylene pipes; chlorine dioxide; degradation; Polymer chemistry; Polymerkemi;

    Sammanfattning : This thesis presents the study of antioxidants depletions in chlorinated media (10 ppm Cl2 - and ClO2 - aqueous media), polyethylene pipes degradations scenarios and migration of the degraded species to aqueous phase. Pressure testing on pipes and squalane testing with controlled pH aqueous media (6.8 ± 0. LÄS MER

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

    Författare :Hans Gruber; Chalmers tekniska högskola; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  7. 5. Aspects of building geometry and powder characteristics in powder bed fusion

    Författare :Alexander Leicht; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; direct metal laser sintering; stainless steel; powder recycling; thin wall structures; 316L; microstructure; electron beam melting; powder bed fusion; additive manufacturing;

    Sammanfattning : Additive manufacturing (AM) produces near-net-shaped parts directly from a 3D-CAD model in a layer-by-layer manner. One of the most common AM technique for fabricating metallic components is powder bed fusion (PBF). The PBF process has shown great potential in fabricating metallic parts with properties better or comparable to conventional methods. LÄS MER