The influence of pre-deformation on the microstructure, mechanical properties, and corrosion behavior of AA2029-T8 was investigated. The pre-deformation may potentially impede the formation of Mg-Ag clusters during the early stage of aging, altered the normal precipitation sequence of the alloy, and significantly increased dislocation density that facilitated non-uniform nucleation of S phase at dislocations, resulting in finer dispersion of precipitation. Moreover, it led to a decrease in Ω phase volume fraction and comparable aspect ratio(diameter/thickness). With increasing deformation, aging response was accelerated, leading to shorter time to peak strength but reduced plasticity. Additionally, the width of precipitate-free zone (PFZ) remained relatively unchanged with increasing pre-deformation; however, average size of grain boundary precipitates (GBPs) decreased while becoming more discontinuous. This resulted in narrowing intergranular corrosion (IGC) channels and decreased maximum corrosion depth as well as a transition from IGC to pitting corrosion behavior. These findings suggest that the mechanical properties and corrosion resistance of the alloy can be improved by increasing pre-deformation levels.

中文翻译：

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预变形对Al-Cu-Mg-Ag合金显微组织、力学性能及腐蚀性能的影响

研究了预变形对AA2029-T8显微组织、力学性能和腐蚀行为的影响。预变形可能会阻碍时效早期阶段Mg-Ag簇的形成，改变合金的正常沉淀顺序，并显着增加位错密度，促进位错处S相的不均匀形核，从而导致更细的合金化。降水分散。此外，它还导致Ω相体积分数和可比较的长径比（直径/厚度）的降低。随着变形的增加，时效反应加速，导致达到峰值强度的时间缩短，但塑性降低。此外，随着预变形的增加，无析出区（PFZ）的宽度保持相对不变；然而，晶界析出物（GBP）的平均尺寸减小，同时变得更加不连续。这导致晶间腐蚀 (IGC) 通道变窄、最大腐蚀深度减小以及从 IGC 向点蚀行为的转变。这些发现表明，通过增加预变形水平可以提高合金的机械性能和耐腐蚀性。