|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Magnesium Technology 2016
||What is a Strain Hardening "Plateau"?
||Sean Agnew, Chris Calhoun, Jishnu Bhattacharyya
|On-Site Speaker (Planned)
A yield plateau occurs in textured Mg alloys during compressive deformation, and this has been ascribed to the localization of twinning. In fine-grained AZ31, this plateau was explained by a region of large twin volume fraction nucleating in a small band and propagating, similar to a Luders band. Once the band traverses the entire gauge length, the sample begins to strain harden. Using digital image correlation, extruded alloy ZK60 samples are also shown to exhibit a Luders like phenomena during compression along the extrusion direction. However, the strain within the band is not sufficient to fully explain the apparent, low strain hardening rate, plateau in the stress-strain curve. Interrupted electron backscattered diffraction (EBSD) reveals that twinning occurs in large elongated grains before spreading to the finer grains. It is suggested that the bimodal grain size distribution combines with the Luders band to explain the plateau in the stress strain curve.
||Planned: A combination print-CD volume