Search for dissertations about: "electron cooling"

Showing result 11 - 15 of 101 swedish dissertations containing the words electron cooling.

  2. 11. Electron beam powder bed fusion of Nitinol : A development from production process window towards delicate structures

    Author : Lin Zeyu; Amir Rashid; Carolin Körner; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Production Engineering; Industriell produktion;

    Abstract : Electron beam powder bed fusion (PBF-EB) is increasingly attracting attention for manufacturing the near-net shape parts due to its incomparable merits, such as free residual stress and superior mechanical performance. Nickel Titanium (NiTi) as the most widely used functional alloy, has not been systematically explored for manufacturing using PBF-EB despite the perfect vacuum and high temperature manufacturing environment. READ MORE

  4. 12. Electron beam-powder bed fusion of Alloy 718 : Effect of process parameters on microstructure evolution

    Author : Paria Karimi Neghlani; Joel Andersson; Joakim Ålgårdh; Iain Todd; Högskolan Väst; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Additive manufacturing; Electron beam-powder bed fusion; Microstructure evolution; Microstructure tailoring; Process understanding; Alloy 718; Production Technology; Produktionsteknik;

    Abstract : Additive manufacturing (AM) is the technology of building 3D parts through layer-by-layer addition of material. Of the different types of AM techniques, electron beam-powder bed fusion (EB-PBF) has been used in this study. EB-PBF can build parts by melting metallic powders using an electron beam as the energy source. READ MORE

  5. 13. Evolution of WC-Co cemented carbide microstructure during creep testing

    Author : Mohamed Amine Yousfi; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; plastic deformation; cemented carbides; linear intercept; transmission electron microscopy.; electron backscattered diffraction; Atom probe tomography;

    Abstract : The aim of this work is to understand the mechanisms behind the plastic deformation of WC-­Co based cemented carbides. The microstructures of two materials have been investigated before and after creep deformation using quantitative microscopy, atom probe tomography, and transmission electron microscopy. READ MORE

  6. 14. Time-Resolved Photoemission Electron Microscopy: Development and Applications

    Author : Lukas Wittenbecher; NanoLund: Centre for Nanoscience; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; PEEM; time-resolved PEEM; ultrafast optics; pulse shaping; plasmonics; semiconductor nanowires; hot electrons; ultrafast microscopy; charge carrier relaxation;

    Abstract : Time-resolved photoemission electron microscopy (TR-PEEM) belongs to a class of experimental techniquescombining the spatial resolution of electron-based microscopy with the time resolution of ultrafast opticalspectroscopy. This combination provides insight into fundamental processes on the nanometer spatial andfemto/picosecond time scale, such as charge carrier transport in semiconductors or collective excitations ofconduction band electrons at metal surfaces. READ MORE

  7. 15. Transmission Electron Microscopy of III-V Nanowires and Nanotrees

    Author : Lisa Karlsson; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Technological sciences; Naturvetenskap; Natural science; nanowires; TEM; III-V; Teknik;

    Abstract : In this work, the morphology and crystal structure of epitaxial semiconductor nanowire structures grown by metal-organic vapour phase epitaxy (MOVPE) are studied by electron microscopy methods. In particular, the three-dimensional structure of nanowires and nanotrees has been characterised by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and multi-slice (MS) simulations. READ MORE