Effect of rolling deformation and passes on microstructure and mechanical properties of 7075 aluminum alloy

Abstract

The research on Al–Zn–Mg–Cu alloys mainly focuses on the effects of solution aging and strain rate on the microstructure and properties of the alloy, as well as the flow stress behavior of the alloy. There are few studies on the effects of hot rolling deformation and reduction pass on the microstructure and properties of aluminum alloy. The dislocation density of alloy is affected by changing the rolling deformation, and post-heat treatment improves fine grains segregation and break coarse second phases. The alloys comprehensive mechanical properties are improved by controlling the recrystallization fraction and size. Different shape variable rolling and different passes, optical microscope (OM), field emission scanning electron microscope (SEM) with energy dispersive spectrometers (EDS), X-ray diffractometer (XRD), microhardness tester, and other methods were used to characterize the samples, and simulation of the rolling process analyzed by Deform-3D software. The effects of hot rolling deformation and deformation pass on microstructure and properties of aluminum alloy were also studied. The results show that dynamic recrystallization was beneficial to grain refinement when deformation increases to 40%. The coarse second phase was broken and refined into chains and partially spheroidized to dissolve in the matrix under large deformation. Dislocation density decreased after solution treatment when deformation was less than 80%, and increased after large deformation was 80%. The equivalent strain obtained by numerical simulations increases with the increase of deformation. The maximum equivalent strain was on both sides of the rolling surface, and this area was the most prone to crack in rolling. When the increase of the shape variable, the recrystallization volume fraction increased, and the grain size decreased.