|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||High Entropy Alloys IV
||Mechanical Study of a Refractory bcc High Entropy Solid Solution: Deformation Mechanisms and Strain Rate Effect
||Jean-Philippe Couzinie, Lola Lilensten, Guy DIRRAS, David Tingaud, Loïc Perriere, Jeno Gubicza, Ivan GUILLOT, Hervé Couque
|On-Site Speaker (Planned)
The deformation behavior of an bcc equimolar TiZrHfNbTa solid solution is presented under a wide range of strain rates between 10(-3)s-1 and 10(+4)s-1 at room temperature. After adequate thermo-mechanical treatments to control the grain size, tensile testing experiments are performed in the quasi-static regime and relaxation steps are performed to highlight thermally activated dislocation mechanisms of the bcc alloy. Activation volumes are plastic-strain independent and coherent with a Peierls mechanism due to strong intrinsic lattice friction. From TEM observations (and also X-ray line profile analysis) evidence is made that dislocation glide is controlled in the first stages by the movement of screw dislocations with a/2<111> Burgers vector. Possible non-Schmid effects in the high entropy solid solution will be discussed. At highest strain rates through impact testing, deformation is localized mainly in macroscopic shear bands. The possible reasons of such band formation will be proposed in the light of the EBSD study.
||Planned: A print-only volume