The static softening behavior of A5083 aluminum alloy with different initial microstructures was studied using various characterization techniques. To calculate the recrystallized fraction, in compression test, a new method based on offset yield stress and Hall–Petch relationship proposed, which is more accurate than conventional methods applicable even when microstructure complex. And relaxati...

The effects of grain size and boundary stability on the mechanical fatigue properties nanocrystalline nickel thin films were examined. We found that tended to decrease with amount sodium allylsulfonate, solution side was larger than substrate side. dependence 0.2% proof strength, tensile limit could be expressed by Hall–Petch equation. strength annealed film are lower those as-deposited film, w...

The flow stress of Hadfield steel is attributed to lattice friction, dynamic strain aging (DSA), mechanical twinning, and forest hardening. However, it has not been clarified yet which mechanism quantitatively contributes most the work Here, an austenitic containing 1.1 wt.% C 12.5 Mn was studied, tensile tests at a rate 1 s−1 were performed neglect DSA effect. friction estimated by Hall–Petch ...

In the present research work, hydro-mechanical deep drawing (HMDD) process of 2024 aluminum alloy is performed experimentally and numerically for elevated temperatures. The main variables forming include fluid pressure, pre-bulge temperature. effects these parameters on thickness distribution uniformity index final product have been investigated. Using hardness test, preferred crystallographic ...

When a strongly textured hexagonal close packed (HCP) metal is loaded under an orientation causing profuse twinning or detwinning, the stress-strain curve is sigmoidal in shape and inflects at some threshold. Authors have largely attributed the dramatic stress increase in the lower-bound vicinity of the inflection point to a combined effect of a Hall-Petch mechanism correlated to grain refineme...

Plastic deformation of nanocrystalline Fe was investigated by nanoindentation. Samples, synthesized by mechanical attrition, consisted of powder particles with diameters greater than 30 mm. The average grain diameters within the particles of different samples ranged from 10 nm to 10 mm. To avoid potential artifacts, samples were prepared without use of heat treatment, and measurements were cond...

A novel design electroplating spring frame MEMS structure specimen is demonstrated here. The specimen can be fit into a specially designed microtensile apparatus which is capable of carrying out a series of tests on submicro scale freestanding thin films. Certain thin films applicable in MEMS were tested including sputtered Chrome, Nicole, Copper, Tantalum Nitride thin films. Metal specimens we...

A system of four coupled rate equations for the development of the densities of mobile and redundant dislocations and of mobile and immobile disclinations with time or strain is proposed to describe the microstructure evolution up to large strains. The densities of redundant dislocations and of immobile disclinations are connected to ow stress contributions with the help of Mughrabi's composite...