2022-04-06 08:00:00
The overall response of elasto-viscoplastic polycrystals demonstrates non-Maxwellian, long-memory effects, while constituent single crystals show Maxwellian, short-memory behaviour. To characterize this emergent behaviour, this work presents analytical homogenization estimates for the elasto-viscoplastic polycrystals and demonstrate that large viscoplastic nonlinearity or anisotropy for the single…
Materials scientists developing novel solid phase processing methods require an atomic level understanding of deformation induced dynamic microstructural evolution. This same goal is also relevant to researchers interested in understanding how atomic locations in materials are modified from the initial state when exposed to…
Ductile failure is a multi-scale phenomenon. In metals, atomic deformation mechanisms interact with micromechanical length-scales defined by the size and distribution of microscopic defects to trigger damage through void nucleation and growth. Coarser length-scales appear with inter-void interactions that coalesce to form mesoscopic damage…
In a nuclear reactor, the reactor pressure vessel (RPV) serves as a critical safety barrier for preventing the release of radiation to environment during accident scenarios. RPV is made of Fe-base ferritic steels that may contain a small amount of insoluble copper. Under neutron…
A variety of methods were developed in the past to capture the microstructure evolution of metals, however, the numerical representation of slip and twin mechanisms is still posing a challenge to date. We discuss the advantages, drawbacks and limitations of existing approaches
Funding opportunities, in particular those that promote and support collaboration among academia, National Labs, and industry, will be discussed, with an emphasis on those pertaining to Materials and Structures in Extreme Environments.
Understanding dislocation mobility is key to understanding material strength: how materials deform and the energy required to do so. An important unsolved question in this regard is whether dislocations can accelerate to supersonic speeds in metals. Previous molecular dynamics (MD) simulations in cubic crystals…
Shock, impact, and ballistic loading include complex stress states, pressures of tens of GPa to Mbar, and high strain rate. In situ studies, in which the evolution of microstructure and properties is monitored during loading, are particularly difficult due to the short time scale…
Deformation twining is a well-known plastic deformation mechanism observed in HCP crystals such as Ti. This presentation highlights observance of different types of twinning (tension and/or compression) along with it’s variant for various types of applied loading on Ti single crystals along different directions…
Mechanical twinning is a form of inelastic deformation observed extensively in low symmetry crystals, such as magnesium and other hexagonal close-packed (HCP) metals. The presence and formation of twins have been shown to have drastic effects on the strength and ductility of these metals….
