Sökning: ".kappa.-Al2O3"

Hittade 5 avhandlingar innehållade ordet .kappa.-Al2O3.

  1. 1. The microstructure and stability of CVD aluminia coatings

    Författare :Mats Halvarsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; .kappa.-Al2O3; SEM; multilayers; TEM; .alpha.-Al2O3; phase transformation; CVD; XRD; microstructure;

    Sammanfattning : This thesis has examined topics of relevance for increasing the understanding of alumina coatings produced by Chemical Vapour Deposition. The work consists of three parts: (i) The microstructure of Al2O3 coatings; (ii) the .kappa.-Al2O3 -> . LÄS MER

  3. 2. Microstructure and Wear of CVD Coatings used in Metal Cutting Applications

    Författare :Andreas Larsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MTCVD; Ca-treated steel; EFTEM; CVD; TEM; Ti C; alfa-Al2O3; gamma-Al2O3; wear; kappa-Al2O3; N ; EELS;

    Sammanfattning : This thesis is concerned with the microstructural characterisation of wear resistant Al2O3 and Ti(C,N)coatings produced by chemical vapour deposition on cemented carbide cutting tools. The investigation focuses on the effect of deposition conditions on the microstructure and the microstructural evolution of the coatings during heat-treatments and metal cutting. LÄS MER

  4. 3. Metastable Alumina from Theory: Bulk, Surface, and Growth of κ-Al2O3

    Författare :Carlo Ruberto; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density-functional theory; structure; cutting tools; plane waves; first principles; stability; one-dimensional electron gas; DFT; Tasker s rules; ionic crystals; polar surfaces; adsorption; pseudopotentials; Pauling s rules; bonding; surface states; TiC; ceramic materials;

    Sammanfattning : Aluminas are materials of high technological importance that show a fascinating structural flexibility, with a large amount of different phases (alpha, gamma, eta, delta, kappa, chi, ...) and phase transitions at relatively high temperatures. LÄS MER

  5. 4. Alumina (Al2O3) and Oxidation of Aluminium. A First-Principles Study

    Författare :Yashar Yourdshahyan; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Aluminum oxides and oxidation mechanisms are topics for extensive research. One good reason for this is their wide range of applications. For instance, the .alfa. LÄS MER

  7. 5. Computer Simulations in Materials Physics: Time-scales and Accuracy

    Författare :Urban Engberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; basis sets; computer simulations; pseudopotentials; materials physics; density functional theory; transition state theory; O N ; quantum Monte Carlo;

    Sammanfattning : Computer simulations are expected to play an increasingly important role within materials physics in the future. Owing to a combination of accurate physical approximations, improved implementations of these approximations, and the exponentially increasing power of computers, problems can now be solved on length and time-scales which were unimaginable only a decade ago. LÄS MER