Structure and Hardness of Cryorolled and Heat-Treated 2xxx Aluminum Alloy

Abstract

The effects of severe plastic deformation (SPD) by isothermal rolling at the temperature of liquid nitrogen combined with prior- and post-SPD heat treatment, on microstructure and hardness of Al-4.4%Cu-1.4%Mg-0.7%Mn (D16) alloy were investigated. It was found no nanostructuring even after straining to 75%. Сryodeformation leads to microshear banding and processing the high-density dislocation substructures with a cell size of ~ 100-200 nm. Such a structure remains almost stable under 1 hr annealing up to 200oC and with further temperature increase initially transforms to bimodal with a small fraction of nanograins and then to uniform coarse grained one. It is found the change in the alloy post–SPD aging response leading to more active decomposition of the preliminary supersaturated aluminum solid solution, and to the alloy extra hardening under aging with shorter times and at lower temperatures compared to T6 temper.

Comparative evaluation of cerium oxide primers electrodeposited on AA2024‐T3 and D16 AM aircraft alloys

“…Regardless these established standard procedures for AA2024‐T3, according to ISO, and for D16 AM, following GOST 4784‐97, the further improvement of these alloys by decrease of their granular structure and intermetallic particle size still remains an object of intensive scientific efforts . Besides, since the primers form intermediated layers between the upper coatings and the metallic surface, their structure is a key factor for the resulting coating adhesion.…”

Influence of Zr on intergranular corrosion of cast and cryorolled D16 aluminum alloy

“…At that in AA alloys it became more complex and inhomogeneous owing to incompleteness of recrystallization, leading to even partial substitution of deformation cells by areas with recovered subgrains and areas of new grains. Besides, inside and along the grain and subgrain boundaries (consequently, recovered and recrystallized structures) nanoprecipitates of different nature and morphology were formed (see more details in [21,22]). In general, such a structure can be characterized as bimodal, consisting of recovered areas with needle (disc)-like S-phase precipitates with a thickness of 2 -10 nm and length up to ~100 nm, and areas of nano / ultrafine (sub) grains with compact slightly elongated precipitates of 10 -50 nm in size.…”

Hardness of cryorolled and artificially aged aluminium alloy D16

“…подробнее в [7,8]). При этом, как было показано в [8], алюминиевая матрица осталась пере-сыщенной основными легирующими элементами и со-хранила способность к последующему дисперсионному твердению при старении.…”

“…Исследования последних лет по разработке новых мето-дов упрочнения металлических материалов, обусловили значительный интерес к деформированию при криоген-ных температурах [1][2][3][4][5][6][7][8]. В результате такого воздейст-вия в чистых металлах и сплавах, как правило, форми-руется развитая дислокационная структура [1][2][3], а при больших пластических деформациях -наноструктура (НС) [4][5][6].…”