About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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Mechanical Behavior at the Nanoscale VI
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Presentation Title |
The Effects of Grain Boundaries on the Micromechanical Properties of Transparent Nanocrystalline Spinel |
Author(s) |
Jessica M. Maita, Sarshad Rommel, Jacob R. Davis, James Wollmershauser, Edward Gorzkowski, Boris Feigelson, Mark Aindow, Seok-Woo Lee |
On-Site Speaker (Planned) |
Jessica M. Maita |
Abstract Scope |
Transparent materials are used extensively due to their ability to transmit light and provide physical protection from chemical and mechanical interactions. The state-of-the-art transparent nanocrystalline MgAl₂O₄ with grain sizes ranging 3.7-80 nm, the smallest currently reported, has been fabricated using high-pressure sintering which can effectively suppress grain growth. Transmission electron microscopy revealed the presence of nanoscale angular pores for grain sizes greater than 10.5 nm but full densification for smaller ones. Nanoindentation, micropillar compression, and micro-cantilever testing were performed to elucidate the effects of grain size on plasticity and fracture properties. We found that both the maximum hardness in nanoindentation and maximum fracture strength in micropillar compression occurs at 10.5 nm grain size, below which the grain-boundary-assisted mechanism promotes plastic deformation under nanoindentation and fracture under uniaxial compression. Our results show that the grain-boundary-assisted process plays an important role in various deformation and fracture modes. |
Proceedings Inclusion? |
Planned: |