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Visar resultat 1 - 5 av 20 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Triboactive Component Coatings : Tribological Testing and Microanalysis of Low-Friction Tribofilms

    Författare :Fredrik Gustavsson; Staffan Jacobson; Bojan Podgornik; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tribofilms; low-friction coatings; tungsten disulfide; TEM; Materialvetenskap; Materials Science;

    Sammanfattning : Coatings are often used on critical components in machines and engines to reduce wear and to provide low friction in order to reduce energy losses and the environmental impact.A triboactive coating not only provides this desired performance, it also actively maintains the low friction by a structural or chemical change in a very thin top layer of these already micrometer thin coatings. LÄS MER

  3. 2. On the Formation of Low-Friction Tribofilms in Me-DLC – Steel Sliding Contacts

    Författare :Nils Stavlid; Urban Wiklund; Sture Hogmark; Erik Johansson; Uppsala universitet; []
    Nyckelord :Materials science; tribofilms; tribochemistry; boundary-lubrication; ESCA; Materialvetenskap;

    Sammanfattning : The present thesis thoroughly treats a special friction reduction phenomenon that may appear in boundary lubricated tribological contacts, of the type encountered in numerous mechanical components made of steel. The phenomenon involves the formation of a special type of tribofilm that offers very low coefficients of friction. LÄS MER

  4. 3. Triboactive Low-Friction Coatings Based on Sulfides and Carbides

    Författare :Jill Sundberg; Ulf Jansson; Jochen M. Schneider; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coatings; thin films; tribology; tungsten disulfide; transition metal dichalcogenide; nanocomposite; TiC a-C; tribofilms; PVD; XPS; HAXPES; XRD; SEM; TEM; Raman spectroscopy; nanoindentation; Kemi med inriktning mot oorganisk kemi; Chemistry with specialization in Inorganic Chemistry;

    Sammanfattning : For sustainable development, it is highly important to limit the loss of energy and materials in machines used for transportation, manufacturing, and other purposes. Large improvements can be achieved by reducing friction and wear in machine elements, for example by the application of coatings. LÄS MER

  5. 4. Protective Tribofilms on Combustion Engine Valves

    Författare :Robin Elo; Staffan Jacobson; Mikael Åstrand; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Internal combustion engine; valve; sealing surface; tribofilm; oil residue; test rig; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

    Sammanfattning : Inside the complex machinery of modern heavy-duty engines, the sealing surfaces of the valve and valve seat insert have to endure. Right next to the combustion, temperatures are high and high pressure deforms the components, causing a small relative motion in the interface. LÄS MER

  7. 5. Formation and Function of Low-Friction Tribofilms

    Författare :Harald Skiöld Nyberg; Staffan Jacobson; Allan Matthews; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tribology; tribofilm; PVD; coating; low-friction; tungsten disulphide; transition metal dichalcogenide; tribochemistry; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

    Sammanfattning : The use of low-friction coatings on machine elements is steadily increasing, and they are expected to play an important role in the reduction of fuel consumption of future motorized vehicles. Many low-friction coatings function by transformation of the outermost coating layer into tribofilms, which then cover the coating surface and its counter surface. LÄS MER