Papers by Keyword: Plastic Deformation Mechanisms

Abstract: The compressive deformation behavior of as-cast Zr55.9Cu18.6Ta8Al7.5Ni10 Bulk Metallic Glass (BMG) composite with micro-scale particles of Ta-rich solid solution embedded in an amorphous matrix was investigated in the supercooled liquid region. It was found that the apparent viscosity of the BMG is dependent on temperature and strain rate. A deviation from a Newtonian behavior was observed at high strain rate and low temperature. The experimental results can be described by a master curve based on a stretched exponential function and the free volume theory. The structural state and the thermal ability of the BMG composite after deformation are also discussed in the paper.

Abstract: An in situ study of the plastic deformation of <001> single crystals of an industrial superalloy has been performed at 850 °C in a TEM to observe directly the micromechanisms which control the deformation under the actual temperature and stress conditions experienced by this material in aeroengines. A comparison between the creation and propagation modes of moving dislocations in the standard microstructure after annealing and the rafted microstructure after 20 h of creep at 1050°C evidence the important role of the width of the γ channels as well as the strength of the γ/γ’ interface in controlling the shearing events of γ’ channels.