Twin formation, propagation, and intersections at the mesoscale

Irene Beyerlein, University of California, Santa Barbara, Santa Barbara, USA

Hexagonal close packed (HCP) crystalline materials, such as Mg and Ti, can provide a potential solution to the ever-increasing portfolio of structural applications that require advanced materials with unprecedented combinations of mechanical properties. Successful incorporation of HCP materials into engineering designs is, however, hindered by their limited plasticity. Perhaps one of the most important and puzzling underlying mechanisms governing their plastic behavior is deformation twinning, which form in these materials under straining and most often at the boundaries between the crystals. The nucleation of twins both inside the crystal and at crystalline boundaries has mostly been addressed at the atomistic scale level. In our research, we employ crystal plasticity based micromechanics model to establish and understand the concept of first formation of twin embryos, propagation inside crystals and across their boundaries, and twin expansion and apply it to Mg and Ti and many of their alloys of great technical interest. This knowledge and insight will be used to accelerate materials discovery and design of HCP alloys of low-density, high strength, high toughness alloys, reducing weight and fuel consumption.

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Session M1: Moday, 25 June 2018

Start: 12:15
End: 01:00 p.m.