Thermally activated deformation processes in body-centered cubic Cr – How microstructure influences strain-rate sensitivity

2015 ◽  
Vol 106 ◽  
pp. 42-45 ◽  
Author(s):  
Verena Maier ◽  
Anton Hohenwarter ◽  
Reinhard Pippan ◽  
Daniel Kiener
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity ◽  
Body Centered Cubic ◽  
Thermally Activated ◽  
Deformation Processes

Deformation behavior and strain rate sensitivity of nanostructured materials at moderate temperatures

2005 ◽  
Vol 880 ◽  
Author(s):  
Cécilie Duhamel ◽  
Sandrine Guérin ◽  
Martin Hÿtch ◽  
Yannick Champion
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Nanostructured Materials ◽  
Strain Rate Sensitivity ◽  
Deformation Behavior ◽  
Rate Sensitivity ◽  
Nanocrystalline Copper ◽  
Fcc Metals ◽  
Thermally Activated ◽  
Increasing Temperature

AbstractStrain-rate jump tests in compression are carried out on nanostructured copper (grain size = 90 nm) at moderate temperatures (353K - 393K). Strain-rate sensitivity m is measured as a function of temperature, T, and strain rate, έ. Increasing temperature or decreasing strain rate induces an increase in the strain-rate sensitivity. For (έ, T) = (1×10-5 s-1, 393K), m is equal to 0.17 which is the highest value reported for nanocrystalline copper. These results of enhanced m are encouraging in terms of gain in ductility. The measurements emphasize the existence of a thermally activated mechanism different from the normal rate-controlling process observed for microcrystalline fcc metals.

scholarly journals Negative Strain Rate Sensitivity Induced by Structure Heterogeneity in Zr64.13Cu15.75Ni10.12Al10 Bulk Metallic Glass

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 339
Author(s):  
Xiang Wang ◽  
Zhi Qiang Ren ◽  
Wei Xiong ◽  
Si Nan Liu ◽  
Ying Liu ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Strain Rate ◽  
Bulk Metallic Glass ◽  
Strain Rate Sensitivity ◽  
Critical Role ◽  
Rate Sensitivity ◽  
Confined Compression ◽  
Negative Strain Rate Sensitivity ◽  
Cast Specimen ◽  
Structure Heterogeneity

The negative strain rate sensitivity (SRS) of metallic glasses is frequently observed. However, the physical essence involved is still not well understood. In the present work, small-angle X-ray scattering (SAXS) and high-resolution transmission electron microscopy (HRTEM) reveal the strong structure heterogeneity at nanometer and tens of nanometer scales, respectively, in bulk metallic glass (BMG) Zr64.13Cu15.75Ni10.12Al10 subjected to fully confined compression processing. A transition of SRS of stress, from 0.012 in the as-cast specimen to −0.005 in compression processed specimen, was observed through nanoindentation. A qualitative formulation clarifies the critical role of internal stress induced by structural heterogeneity in this transition. It reveals the physical origin of this negative SRS frequently reported in structurally heterogeneous BMG alloys and its composites.

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