Sökning: "metal resistance"

Visar resultat 21 - 25 av 291 avhandlingar innehållade orden metal resistance.

  1. 21. Fatigue of Metal Matrix Composites

    Författare :Magnus Levin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mechanical properties; microstructures; manufacture; DMMC;

    Sammanfattning : This thesis treats the mechanical properties of discontinuously reinforced metal matrix composites, DMMCs, in general and their fatigue properties in particular. Methods of manufacture, microstructures and resulting mechanical properties of DMMCs are reviewed in the introductory part. LÄS MER

  3. 22. Tribology at the Cutting Edge : A Study of Material Transfer and Damage Mechanisms in Metal Cutting

    Författare :Julia Lundberg Gerth; Urban Wiklund; Uppsala universitet; []
    Nyckelord :Tribology; Metal cutting; Gear hobbing; Wear; Coating; Residual stress; Material transfer; Steel; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

    Sammanfattning : The vision of this thesis is to improve the metal cutting process, with emphasis on the cutting tool, to enable stable and economical industrial production while using expensive tools such as hobs. The aim is to increase the tribological understanding of the mechanisms operating at a cutting edge and of how these can be controlled using different tool parameters. LÄS MER

  4. 23. Development of metal hydride surface structures for high power NiMH batteries : Also extended cycle-life and lead to more effective recycling methods

    Författare :Yang Shen; Dag Noréus; Andreas Züttel; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Metal hydrides; NiMH batteries; Surface treatment; Ni clusters; Rare earths hydroxides; Oxygen; Hydrogen; Inorganic Chemistry; oorganisk kemi;

    Sammanfattning : By combining alkaline etching of hydrogen storage alloys or their hydrides with a controlled oxidation, it was possible to improve reaction kinetics and accelerate activation of MH-electrodes. Both AB5 and AB2 alloys were studied where A is mixtures of rare earth elements for AB5 alloys and titanium and/or vanadium, zirconium for AB2 alloys; nickel contributes the major part of B. LÄS MER

  5. 24. Study of Electrochemical Behaviour and Corrosion Resistance of Materials for Pacemaker Lead Applications

    Författare :Andreas Örnberg; Jinshan Pan; Jukka Lausmaa; Ann Cornell; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Co-base alloy; 35N LT; MP35N; Ta; TiN coating; electrochemical behaviour; corrosion resistance; Chemistry; Kemi;

    Sammanfattning : For patients suffering bradycardia, i.e., too slow heart rhythm, the common treatment is having a pacemaker implanted. The pacemaker system consists of the pacemaker and a pacing lead. LÄS MER

  7. 25. DESIREE: Instrumentation Developments and Hot Metal Cluster Decays

    Författare :Emma K. Anderson; Henning Schmidt; Henrik Cederquist; Henning Zettergren; Oded Heber; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DESIREE; microchannel plate; clusters; spontaneous decay; small metal cluster anions; silver; copper; gold; carbon dianions; fragmentation; vibrational autodetachment; DESIREE; mikrokanalplattor; kluster; spontana sönderfall; små metallklusteranjoner; silver; koppar; guld; kol di-anjoner; fragmentering; Physics; fysik;

    Sammanfattning : This thesis presents instrumentation developments and measurements performed at the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. DESIREE operates at cryogenic temperatures ~13 K, with very low background pressures of ~10-14mbar, allowing the observation of stored ions to long times of tens of seconds and longer. LÄS MER