The origin of the boundary strengthening in polycrystal-inspired architected materials

Crystal-inspired approach is found to be highly successful in designing extraordinarily damage-tolerant architected materials. i.e. meta-crystals, necessitating in-depth fundamental studies to reveal the underlying mechanisms responsible for the strengthening in meta-crystals. Such understanding will enable greater confidence to control not only strength, but also spatial local deformation. In this study, the mechanisms underlying shear band activities were investigated and discussed to provide a solid basis for predicting and controlling the local deformation behaviour in meta-crystals. The boundary strengthening in polycrystal-like meta-crystals was found to relate to the interaction between shear bands and polygrain-like boundaries. More importantly, the boundary type and coherency were found to be influential as they govern the transmission of shear bands across meta-grains boundaries. The obtained insights in this study provide crucial knowledge in developing high strength architected materials with great capacity in controlling and programming the mechanical strength and damage path. Polycrystal-inspired architected materials are found to be high strength and damage tolerant. Here, the authors conduct in-depth work to unravel the mechanism responsible for the hardening phenomenon, in particular the role of polygrain-like boundary in the post-yield shear band activities.

Automated summary

The crystal-inspired approach has been successful in designing damage-tolerant architected materials, such as meta-crystals, leading to the need for fundamental studies to understand the underlying mechanisms responsible for strength and deformation control. Boundary strengthening in polycrystal-like meta-crystals is influenced by the interaction between shear bands and polygrain-like boundaries, with boundary type and coherency playing a key role in governing shear band transmission across meta-grain boundaries. Insights gained from this study are crucial for developing high-strength architected materials with the ability to control and program mechanical strength and damage path.