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...

Abstract Size effects in metal plasticity are widely accepted, and different theoretical approaches to handle the phenomenon developing literature. The present work considers Fleck Willis (2009b) framework, creates a new gradient enhanced rate-independent crystal FE-implementation. study both energetic dissipative hardening strengthening, adopts general form of effective slip rate. Monotonic cy...

Severe plastic deformation is a technical method to produce functional material with special properties such as high strength and specific physical properties. Selection of an efficient severe plastic deformation for grain refinement is a challenging field of study and using a modeling technique to predict the refinement efficiency has gained a lot of attentions. A comparative study was carried...

In latest years small scale machining has been widely used in advanced engineering applications such as medical and optical devices, micro- nano-electro-mechanical systems. micromachining of metals, a depth cut becomes usually smaller than an average crystal size polycrystalline structure; thus, the cutting process zone can be localized fully indoors single grain. Due to crystallographic anisot...

Using a dislocations-based model of slip and crystal plasticity, we show by illustrative examples that the experimentally observed increase in the yield stress of very thin metallic membranes most likely is due to the variation of grain orientations through the thickness of the membrane, as well as the surface hardness due to oxidation or contamination, both of which generally are insignificant...

We show that slowly sheared metallic nanocrystals deform via discrete strain bursts (slips), whose size distributions follow power laws with stress-dependent cutoffs. We show for the first time that plasticity reflects tuned criticality, by collapsing the stress-dependent slip-size distributions onto a predicted scaling function. Both power-law exponents and scaling function agree with mean-fie...

A Crystal Plasticity Finite Element (CPFE) framework is proposed for modeling the non-Schmid yield behavior of L12 type Ni3Al crystals and Ni-based superalloys. This relies on estimation model parameters directly from orientation- temperature-dependent experimental stress data. The inelastic deformation extended to precipitate phase superalloys in a homogenized dislocation density based crystal...