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

Abstract

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 MgZn 2 and CuMgAl along the matrix that provides plastic strengthening.

Temperature and annealing time influences on cross-rolled 7475-T7351 aluminum alloy

“…[13,14] In addition to the T7351 treatment, cold forming processes, such as rolling, can also be used to increase the tensile strength of the 7XXX series aluminum alloys [7,10]. During cold forming processes, important events occur that change the mechanical properties, such as: increase in dislocations density (hardening) and vacancy, change in grain shape which become elongated in the mechanical work direction, and developing crystallographic texture [15][16][17][18][19].…”