Claims are often found in the literature that metallic materials can be nanocrystallized by severe plastic deformation (SPD). However, SPD does not generate a well-defined nanocrystalline (NC) material, which can be achieved by subsequent annealing/recovery treatment. In this study, molecular dynamics (MD) simulation is employed to study the effect of annealing on structure and mechanical prope...

The autonomous repair mechanism of creep cavitation during high-temperature deformation has been investigated in Fe-Au and Fe-Au-B-N alloys. Combined electron-microscopy techniques and atom probe tomography reveal how the improved creep properties result from Au precipitation within the creep cavities, preferentially formed on grain boundaries oriented perpendicular to the applied stress. The s...

Tensile–creep experiments were conducted in the temperature range 100–200 C and stress range 20–83 MPa for a series of magnesium–zinc–yttrium (Mg-Zn-Y) and mangnesium-zinc–zirconium (Mg-ZnZr) alloys ranging from 0 to 5.4 wt% Zn, 0 to 3 wt% Y, and 0 to 0.6 wt.% Zr. The greatest tensile– creep resistance was exhibited by an Mg–4.1Zn–0.2Y alloy. The room-temperature yield strength increased with i...

High-resolution electron backscatter diffraction (EBSD) was used to examine the grain structure in long rods of ultrafine-grain (UFG) commercial-purity titanium produced for medical implants. The UFG material was obtained by equal channel angular pressing (ECAP) using a Conform scheme followed by rod drawing. The microstructure was found to be bimodal consisting of relatively coarse elongated g...

Barsoum and El-Raghy [1] have recently developed reactive hot-pressing techniques to form bulk, polycrystalline Ti3SiC2 from powders of Ti, SiC, and graphite. This ternary carbide, first synthesized by Jeitschko and Nowotny [2] in the late 1960s, exhibits a rather surprising combination of properties. Not only is the ratio of hardness (;4 GPa) to elastic modulus (;320 GPa) more typical of ducti...

An AM30 magnesium alloy was processed through ECAP method at 200 °C. Optical and transmission electron microscopy as well as electron back scattered diffraction (EBSD) technique were employed to characterize the deformed microstructure. A partially recrystallized microstructure including ultrafine/nano structures was obtained. The area fraction of 49% was measured for the recrystallized regions...

– To analyse a polycrystalline material which has undergone mechanical sollicitations, we quantify the deformation of grain boundaries. We investigate a pattern which records past deformations: a deep ice core, in Dome Concordia, Antarctica. Its ice microstructure (grain boundaries) is a key feature useful to study ice evolution and to investigate climatic changes. Our method extracts quantitat...