|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Microstructural Template Consisting of a Face-Centered Cubic Matrix with Ordered Precipitates: Microstructural Evolution and Properties
||Impact of L1<sub>2</sub>-phase Dispersoids on the Hardening Behavior of Multi-phase Strengthened Aluminum Alloys
||Viktor Wessely, Robin Schäublin, Stephan S. A. Gerstl, Stefan Pogatscher, Peter J. Uggowitzer, Jörg Löffler
|On-Site Speaker (Planned)
We focus on a new generation of hardenable aluminum alloys based on the concept of high-strength Al–Sc alloys that form coherent L1<sub>2</sub> structured precipitates. Replacing scandium by more cost-effective elements potentially opens new fields of applications. Suitable candidates are rare-earth or transition metals, such as Er, Zr, Hf or Yb. In this study we have deployed thermodynamic (CALPHAD) and kinetic modelling to design alloys and their heat treatments, with subsequent mechanical and microstructural characterization. 7xxx-series alloys with < 0.5 wt.% Er and Zr have been systematically studied. High-resolution transmission electron microscopy (TEM) and chemical mapping provided the composition, size distribution, and number density of the nanometric dispersoids and their structural relationship with the matrix. Correlative TEM-APT (atom-probe tomography) measurements suggest that the Al<sub>3</sub>(Er,Zr) phase detected significantly increases the precipitation kinetics of subsequent hardening phases which formed at lower temperatures. Additional TEM in-situ heating experiments validated the modelling study.
||Planned: Supplemental Proceedings volume