On the mechanical behavior of an Al 7075 alloy deformed by asymmetrical and conventional rolling

Resumo

Samples of the Al 7075 naturally and artificially aged were processed by conventional and asymmetrical
rolling with 5% of thickness reduction. The rolling processes were evaluated under room temperature and
under warm condition (130°C). Mechanical properties were evaluated by uniaxial tensile and Vickers
microhardness tests. Microstructure evolutions were followed by optical microscopy analysis. Naturally aged
samples showed better yield strengthening under warm processing. Greater ultimate stress and ductility under
room temperature processing was also noticed in naturally aged specimens. Artificially aged samples showed
better mechanical properties under room temperature, softening under warm processing due to grain recovery
process. Microhardness tests showed expected results for both rolling types, especially on asymmetrical
rolling with the higher predictions were observed. Micrographs have shown no expressive grain changes or
refinement although its flattening was observed. Precipitates were analyzed by EDS/SEM revealing the
presence of MgZn2 and CuMgAl along the matrix that provides plastic strengthening.
Keywords: Aging, asymmetrical rolling, conventional rolling, mechanical behavior, Al 7075 alloy.