Microstructures of nickel deformed by high pressure torsion to high strains

Xiaoxu Huang, Grethe Winther, Niels Hansen, T Hebesberger, A Vorhauer, Reinhard Pippan, Michael Zehetbauer

    Veröffentlichungen: Beitrag in BuchBeitrag in Konferenzband


    Microstructures of nickel deformed by the HPT up to strains of 12.0 have been examined by mean of transmission electron microscopy. Observations have been carried out in the longitudinal section for a proper demonstration of the structure morphology. A cell block structure delineated by extended planar boundaries has been clearly revealed over the strain range investigated. At low to medium strains (von Mises strain ?vM2.5, the extended boundaries are almost parallel to the torsion plane, forming a typical lamellar structure. The evolution of the microstructural parameters, boundary spacing and misorientation, is similar to that observed during the conventional torsion or rolling deformation. That is, the spacing decreases and the misorientation increases with increasing strain. An average spacing of 76nm has been measured at the highest strain ?vM=12.0, and no saturation in the spacing is seen. Two new structural features, deformation twins and equiaxed grains have also been observed to contribute to the structural refinement at high strains.
    TitelTHERMEC'2003 Processing and Manufacturing of Advanced Materials
    Herausgeber (Verlag)Trans Tech Publications Inc.
    PublikationsstatusVeröffentlicht - 2003


    ReiheMaterials Science Forum

    ÖFOS 2012

    • 1030 Physik, Astronomie