12th International Conference on Magnesium Alloys and their Applications (Mg 2021): Formability
Program Organizers: Alan Luo, Ohio State University; Mihriban Pekguleryuz, McGill University; Sean Agnew, University of Virginia; John Allison, University of Michigan; Karl Kainer; Eric Nyberg, Kaiser Aluminum Trentwood; Warren Poole, University of British Columbia; Kumar Sadayappan, CanmetMATERIALS; Bruce Williams, Canmetmaterials Natural Resources Canada; Stephen Yue, Mcgill University
Friday 9:50 AM
June 18, 2021
Room: Invited II
Location: Virtual
Session Chair: David Klaumunzer
9:50 AM Invited
Highly Deformable Mg–Al–Ca Alloy with Al2Ca Precipitates: Leyun Wang1; Gaoming Zhu1; Xiaoqin Zeng1; 1Shanghai Jiao Tong University
Magnesium (Mg) is the lightest structural metal. However, the poor formability of Mg alloys to great extent limits their applications in making structural parts. Formability is strongly correlated to both high tensile elongation and large work hardening capacity. Here, we report a new Mg-Al-Ca alloy in which a majority of deformable Al2Ca precipitates form while the formation of Laves phases of Mg17Al12 and Mg2Ca seems suppressed. Al2Ca precipitates imped dislocation motion, leading to large work hardening. Then, Al2Ca precipitates deform with dislocations and stacking faults under the enhanced flow stress, which relieve local stress concentration and improve tensile elongation. In addition, solutes Al and Ca suppress twin nucleation while promoting <c+a> dislocations in Mg. This new Mg-Al-Ca alloy demonstrates one of the highest combinations of tensile elongation and work hardening capacity among existing Mg alloys. Effect of Zn addition to this new alloy will also be discussed.
10:20 AM Invited
Controlling Deformation Twinning Through Microstructural Engineering: Benjamin Anthony1; Victoria Miller1; 1University of Florida
The stress states surrounding twin-boundary interactions have been widely studied in Mg and other hcp metals, but primarily for single phase alloys. In reality, many commercial Mg alloys contain a substantial volume fraction of hard micron-sized intermetallic particles, primarily located at grain boundaries. These hard particles alter the local stress state, but the role in twinning behavior had not been systematically explored. In this work, we use an elastoplastic fast fourier transform polycrystal plasticity code to systematically interrogate the role that grain boundary particles play in twin propagation, thickening, and transmission across the boundary. The implications for microstructural engineering for enhanced mechanical performance will be discussed.