Microstructure evolution of the hot-rolled modified AA 5083 alloys during the two stage thermal treatment

The effects of the two stage heat treatment on the structure of two hot-rolled 5083 aluminum alloys without and with 0.12% Zr addition were investigated. Combination of the metallographic and transmission electron microscopy (TEM) was carried on in order characterize grain structure as well as precipitates type and morphology. During the homogenization annealing recovery processes and grain structure polygonization were accomplished. Further annealing at the 460°C had little effect on the grain morphology. Two populations of the Mn-based secondary phases were identified: coarser particles containing Fe, while the Mn particles alloyed with Cr were finer. Zr did not precipitate in a form of the fine, coherent precipitate. However, in the alloy containing Zr the recovery appear to be easier and more advanced than in the other alloy

Deformation behavior of the AlMg4.5Cu0.5 type alloy sheet

Deformation behavior of the AlMg4.5Cu0.5 type alloy sheets was examined after cold rolling and annealing in the range of temperature from 220°C to 520°C, water quenching and natural aging. The low temperature annealed samples, characterized by fine grained recrystallized structure and high content of Cu-Mg precipitates, have shown a superior hardening ability in uniaxial tension and formability in biaxial stretching. The natural aging didn't bring any important changes of the properties in respect to the as-quenched condition of the tested material

Effect of annealing temperature on the formability of Al-Mg4.5-Cu0.5 alloy sheets

Formability of Al-Mg4.5-Cu0.5 alloy sheets was tested after annealing at different temperatures (220-520 degrees C) and water quenching. The formability (normalized limiting dome heights, LDH/R) showed only a small variation for all the samples with recrystallized structure, i.e. the LDH/R-e(2) curves were within similar to 13% in the range of plane strain deformation. The samples annealed at 280 degrees C experienced a formability level at the upper limit of the band containing all the LDHIR values. The formability rating seems to be the result of the complex interaction of the strain hardening ability and strain rate sensitivity (SRS) due to different structural features developed during different annealing conditions