In-situ X-ray diffraction during tensile deformation of ultrafine-grained copper using synchrotron radiation
Abstract
At the synchrotron facility, Super Photon Ring - 8 GeV, in-situ X-ray diffraction during tensile deformation was conducted on ultrafine-grained Cu with a grain size of about 300 nm fabricated by equal-channel angular pressing. The diffraction profile was observed with the time resolution of about 1 s using multiple MYTHEN detectors, and the diffraction angle and the full-width at half-maximum of some Bragg peaks were determined using the pseudo-Voigt function. From the analysis of Bragg peaks, it was found out that there are microscopically three regions; elastic, plastic and transition regions. The 0.2% proof stress obtained from the stress-strain curve locates within the microscopic transition region. Microstrain was evaluated using the Williamson-Hall method and the dislocation density was also obtained from the microstrain. The dislocation density starts increasing before 0.2% proof stress, which is associated with dislocation bow-out and emission from grain boundaries. The Taylor relationship seems to be still satisfied after 0.2% proof stress.
- Publication:
-
Philosophical Magazine Letters
- Pub Date:
- August 2016
- DOI:
- 10.1080/09500839.2016.1218563
- Bibcode:
- 2016PMagL..96..294M
- Keywords:
-
- Ultrafine grains;
- in-situ XRD;
- dislocation density;
- copper;
- synchrotron radiation