Sökning: "w c ratio"

Visar resultat 6 - 10 av 37 avhandlingar innehållade orden w c ratio.

1. 6. Microstructure of Cermets

   Författare :Per Lindahl; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; thermodynamic; microchemistry; N ; AP-FIM; Ti C; cutting tools; SEM; cemented carbide; TEM; sintering;

   Sammanfattning : The microstructure of several TiC-TiN-Mo2C-WC-Co/Ni model alloys and a commercial (Ti,Ta,W,Mo)(C,N)-(Co,Ni) type cermet was studied using x-ray diffraction, optical microscopy, scanning electron microscopy, analytical electron microscopy and atom probe field ion microscopy. In addition thermodynamical calculations were made in order to understand the development of the microstructure during sintering. LÄS MER

3. 7. Synthesis and characterization of Mo- and W-based atomic laminates

   Författare :Rahele Meshkian; Johanna Rosén; Per Persson; Arni Sigurdur Ingason; Michael Naguib; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Mn+1AXn (MAX) phases are inherently nanolaminated compounds based on transition metals (M), A group elements (A), and carbon or/and nitrogen (X), which exhibit a unique combination of ceramic and metallic properties. My thesis work has focused on exploring novel MAX phase chemistries, including elemental combinations beyond those traditionally used for MAX phases, and their graphene-analogous 2D counterpart, MXenes. LÄS MER

4. 8. Thermally stable electrical contacts to 6H silicon carbide

   Författare :Nils Lundberg; Mikael Östling; Claude Jaussaud; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; I-V current -voltage ; C-V capacitance-voltage ; rectifying; ohmic; interface; silicide; carbide; epilayer; Schottky barrier height; current rectification ratio CRR ; specific contact resistivity; transmission line model TLM ; contact resistance; transfer length; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Silicon Carbide (SiC) are at present being developed for use in high temperature (≥ 500◦C) and high-power environments under which conventional semiconductors can hardly perform.  Thermally stable electrical contacts are essential to the ability of SiC to function under such extreme conditions. LÄS MER

5. 9. Equilibrium aspects of Cr-alloyed cemented carbides

   Författare :Bartek Kaplan; Malin Selleby; Armando F. Guillermet; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : In view of the extensive use of Cr as a grain growth inhibitor in WC-Co cemented carbides this thesis comprises a combined experimental and ab initio study of a number of critical issues pertaining to phase equilibria of the subsystems to the W-Co-Cr-C system.To be able to predict which of the stable Cr-carbides forms above the solubility limits of Cr and C in the fcc phase the respective solubility of Co in Cr23C6, Cr7C3 and Cr3C2 are investigated experimentally. LÄS MER

7. 10. Moisture Conditions and Frost Resistance of Concrete in Hydraulic Structures

   Författare :Martin Rosenqvist; Avdelningen för Byggnadsmaterial; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydraulic Structures; Hydro Power; Concrete Dams; Concrete; Frost Resistance; Scaling; Spalling; Moisture Absorption; Macroscopic Ice Lens Growth;

   Sammanfattning : Owing to the winter conditions in Sweden, the effects of frost action may have a considerable impact on the deterioration of concrete. Both superficial and internal damage, which are suspected to have been caused by frost action, have been found in concrete in hydraulic structures. LÄS MER