Ultrafine-grained (UFG) metallic materials processed by severe plastic deformation (SPD) techniques often exhibit significantly higher strengths than those calculated the well-known Hall-Petch equation. These result from fact that SPD processing not only forms UFG structure but also leads to formation of other nanostructural features, including dislocation substructures, nanotwins and nanosized...

 J.D., New York University School of Law; Research Fellow & Lecturer in Law, Center for Health & Pharmaceutical Law & Policy, Seton Hall University School of Law. The author was a member of a working group in New Jersey that collaborated to identify issues to assist the State in its drafting of regulations to implement its Medicaid Accountable Care Organization (ACO) legislation, which is the ...

A brief history and update are given in four examples demonstrating that polycrystals generally stronger than their individual component crystal grains because of obstructed dislocation pile-ups at grain boundaries. The example cases constitute diverse applications a Hall–Petch dependence involving one or another aspects the full polycrystal stress–strain behavior: (1) based description for com...

This paper presents the results of studies on true fracture stresses Al alloy 6101 with an ultrafine-grained (UFG) structure processed by equal channel angular pressing — conform (ECAP-C) method and same after artificial aging (AA state). The grain size in UFG state was about 500 nm. Aging particles Al3Fe were present AA state. Strength yield stress increase as a result formation structure. str...

Strengthening by grain refinement via the Hall–Petch mechanism and softening nanograin formation inverse have been subject of argument for decades, particularly ultrafine-grained materials. In this study, relationship is examined magnesium, aluminum, copper, iron produced severe plastic deformation in literature. Magnesium, their alloys follow with a low slope, but an up-break appears when size...

Local mechanical responses near single grain boundaries (GBs) of 9.8 mol% Y2O3-stabilized ZrO2 bicrystals, SrTiO3 bicrystal, and Al2O3 polycrystal were investigated by nanoindentation at room temperature to reveal GB contributions the properties. Contrary concept Hall–Petch strengthening, hardness showed negligible variations among interiors, vicinities, just on GBs in samples. Importantly, may...