Mechanical behavior and microstructure evolution during deformation of AA7075-T651

Study on corrosion resistance of HAZ and TMAZ in friction stir welding joint of 7075 aluminum alloy by thermal simulation

“…The energy of LAGB is lower than that of HAGB, so the diffusion of solute atoms in lower-mobility LAGB is more difficult than that in HAGB [21,22]. Therefore, the solute atoms are easy to diffuse in samples with a relatively more proportion of the HAGBs, which means that the diffusion of solute atoms along the grain boundaries of the sample with a small proportion of LAGB is less difficult [23]. Therefore, the redissolution of η' phase and the precipitation of η phase are easier in samples with a lower percentage of LAGBs, so it shows a low hardness.…”

A new damage evolution criterion for the coupled Eulerian-Lagrangian approach: Application to three-dimensional numerical simulation of segmented chip formation mechanisms in orthogonal cutting

“…However, once certain temperatures are reached, these precipitates begin to progressively grow, losing their strengthening effect and causing a drastic decrease in the material's mechanical strength [24] because of dynamic recovery and dynamic recrystallization. The critical temperatures in the two materials are different, and, based on previous studies, are fixed between 250 − 350 • C for AA6082-T6 [25] and between 200 − 300 • C for AA7075-T6 [26]. Consequently, the η max parameter changes within the ranges until the critical temperature T f is reached, as shown in Fig.…”

Effect of microstructural rearrangement as a result of annealing on the corrosion behavior of 7075 aluminum alloy

“…The beneficial effect to the high strength of AA7000 by the strengthening precipitates are also responsible for the lowering corrosion resistance of the alloys [10,12,13]. Finely dispersed intermetallic precipitates, including Cu-, Fe-, and Mg-rich intermetallics [14,15] create a micro-galvanic coupling with the matrix (i.e., electrochemical potential gradient), making the alloys susceptible to pitting, galvanic, and intergranular corrosion. The precipitates which are nobler tends to induce corrosion of the surrounding matrix, while the anodic precipitates corroded selectively during exposure to corrosive environment.…”

“…Understanding of the relationship between microstructural change and corrosion behavior is therefore essential for obtaining the optimum benefits of high strength and higher corrosion resistance of the AA7000 alloy series. It was reported that thermo-mechanical test on AA7075-T651 at elevated temperatures up to 350 °C induced dynamic recovery on the metallic grains that causes softening of the material, while at 400 and 500 °C a combination of dynamic recovery and recrystallization occurred [15]. It was suggested that transformation of Cu-rich precipitates played significant role in the mechanical properties change during the tests [20,21].…”