On the Zener drag

TL;DR: In this article , a two-step tandem hot rolling (THR) and cold drawing was used to produce AA7050 wire products, and the evolution of second phases, grain microstructures, and micropores during the whole process was thoroughly studied.

Abstract: Abstract We present a state-of-the-art review of the microstructural evolution in rocks under static and deformational conditions. First, the general concepts and processes are introduced using monomineralic aggregates. Then, they are expanded into the more complex context of polymineralic rocks with a dominant matrix phase. The first part of this contribution delivers information on sample strategies to quantify polymineralic microfabrics. Based on comparisons between microfabrics of monomineralic and polymineralic rocks, we use the common knowledge collected over the past decades for monomineralic systems and discuss the differences to polymineralic ones in terms of microstructures, modal compositions, spatial distribution of phases, crystallographic preferred orientations and associated processes. The article puts particular emphasis on the effect of coupled grain growth, mass transfer processes, and deformation mechanisms. We speculate on the effect of mineral reactions during the evolution of microstructures and rheology in polymineralic aggregates at different metamorphic conditions. At the end of the article, we demonstrate the great potential of grain-size evolution maps as microstructural tool to unravel the geological history of polymineralic rocks that evolved under a variety of geodynamic situations.

TL;DR: In this paper, the detailed movement of a dislocation line through a random array of point obstacles in the glide plane has been examined, using a digital computer, on the basis of the line tension approximation.

TL;DR: In this article, the authors examined the impact of a random distribution of point-like obstacles to the movement of dislocations and proved that a critical applied stress exists; it is determined by a critical value of the fraction of passable obstacles such that the average dislocation segment can keep moving.

TL;DR: In this paper, the ease of motion of a dislocation in a crystal is influenced by changes in lattice parameter and elastic modulus, leading to the production of interface dislocations and suggest a work hardening model for one class of precipitation hardened alloys.