Thermally Activated Process during Dislocation Motion in Ultrafine-Grained Copper

Large - scale production of nano - twinned , ultrafine - grained copper

Large-scale production of high purity (99.999%), nano-twinned, and ultrafine-grained copper foils (22 m thick) was successfully implemented by the use of nanoscale multilayer technology. The process allows the production of up to fourteen 10 cm diameter foils during a single deposition run with high levels of reproducibility. Mechanical tests demonstrate that the strength of the Cu foils (σy ∼ ...

Fatigue Crack Resistance of Ultrafine-Grained Copper Structures

Combined Model of Dislocation Motion with Thermally Activated and Drag-dependent Stages

A computational model is developed to study the effect of coupling of thermally activated and drag-dependent processes during dislocation motion through an array of obstacles in metals. The model explicitly includes three successive, reiterative stages typical of such motion: the thermally activated breakoff from an equilibrium position; accelerated drag-dependent motion; and the transition to ...

Ultrafine-Grained Metals

Ultrafine-grained (UFG) metallic materials are at the cutting edge of modern materials science as they exhibit outstanding properties which make them very interesting for prospective structural or functional engineering applications. Due to the progress in severe plastic deformation techniques during the last decade, ultrafine-grained microstructures are no longer only restricted to easy to def...

Austenite Stability during Nanoindentation of Ultrafine and Coarse Grained AISI 304L Stainless Steels

In the present study, the effect of grain size on the austenite stability was studied by nanoindentation tests in a 304L stainless steel. Thermomechanical processing based on cold rolling and annealing was used to produce two different types of austenite: ultrafine grained (UFG) austenite with the average grain size of 0.65 μm and coarse grained (CG) austenite with the average grain size of 12 ...