Sökning: "metallographic investigation"

Hittade 4 avhandlingar innehållade orden metallographic investigation.

  1. 1. Railway Wheel Flats. Martensite Formation, Residual Stresses, and Crack Propagation

    Författare :Johan Jergeus; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sliding contact; metallographic investigation; crack propagation; thermal shock; constitutive modelling; phase transformations; railway wheel flats; full-scale field experiments; transformation plasticity; tread damage; residual stresses; spalling; martensite formation;

    Sammanfattning : A railway wheel flat is a flat spot on the rolling surface of a wheel caused by its unintentional sliding on the rail. The reason for the sliding may be poorly adjusted, frozen or defect brakes, or too high braking forces in relation to the available wheel/rail adhesion. LÄS MER

  2. 2. Microstructure and mechanical properties of Ti-6Al-4V welds produced with different processes

    Författare :Sakari Tolvanen; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fatigue; welding; porosity; microstructure; defects; Ti-6Al-4V;

    Sammanfattning : Titanium alloys are widely used for components in the fan and compressor sections of aeroengines mainly because of their superior strength-to-weight ratio. Large static compressor components can be manufactured by welding together smaller subcomponents, which has potential to provide benefits such as higher buy-to-fly ratio and improved performance of the components. LÄS MER

  3. 3. Fatigue Anisotropy in Forged Components

    Författare :Cornelius Temmel; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Inclusion Cluster; Low Sulfur; Machinability; Inclusion; Manganese Sulfide; Quenching Crack; Forging; Isotropic Quality; Steel; Anisotropy;

    Sammanfattning : Ever-growing requirements on combustion engine efficiency of motor vehicles demand increasing service loads in powertrain components. Optimization of component material is therefore inevitable. A major detriment with many forged transmission components is their anisotropic mechanical behavior, not least during cyclic loading. LÄS MER

  4. 4. Environment Related Surface Phenomena and their Influence on Properties of Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo : Oxidation at Elevated Temperature and Corrosion During Chemical Treatment

    Författare :Birhan Sefer; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materialteknik; Engineering Materials;

    Sammanfattning : This doctoral thesis covers investigation of the surface phenomena of Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo alloys related with oxidation at elevated temperature and corrosion duringchemical treatment in hydrofluoric-nitric acid (HF/HNO3) solutions. The explored phenomenaare related to manufacturing and service conditions of aero-engine components. LÄS MER