Abstract Using advanced electron microscopy techniques, statistical analysis and analytical investigation of precipitates/dispersoids evolution, we demonstrate the critical effect of alloy composition (Sc, Mn, and Mg content) and thermal processing route (heating rate and pre-aging) on the recrystallization behavior of AlScZrMn(Mg) alloys. Two major types of second phases, namely Al3(Sc,Zr) precipitates and α-Al(Mn,Fe)Si dispersoids, were identified in the thermally-treated cold-rolled sheets (of 0.3 mm thickness). Both phases were observed to maintain coherency with the Al matrix at abnormally large sizes (>100 nm and >500 nm, respectively), as well as exhibiting unprecedented levels of thermal stability (i.e., high coarsening resistance). The recrystallization behavior and strength evolution were shown to be a strong function of the size and aerial number density evolution of the precipitates/dispersoids which, in turn, are controlled by the alloy composition and thermal history. Particularly, the recrystallization was effectively mitigated at a slow ramp to 590 °C (a typical brazing temperature for AlMn alloys) whereas a full recrystallization occurred during a faster ramp. Such behavior was explained by the competitive kinetics of Al3(Sc,Zr) precipitation and recrystallization phenomenon at intermediate and high-temperature ranges upon heating to 590 °C. The introduction of a pre-aging treatment within the intermediate temperature range (i.e., 250–400 °C), prior to the fast ramp, was shown to prevent recrystallization due to the stabilization effect of a large aerial number density of finely-dispersed Al3(Sc,Zr) precipitates. A higher Sc content in the alloy enhances such a stabilization effect. Mn additions not only enhance the mitigation of recrystallization (through a refinement of Al3(Sc,Zr) precipitates) but also refines the evolution of α-Al(Mn,Fe)Si dispersoids resulting in a higher yield strength. The Mg addition, on the other hand, has no impact on the evolution of Al3(Sc,Zr) precipitates nor on the recrystallization status, though it causes a refinement of α-Al(Mn,Fe)Si dispersoids and thus leads to a higher final yield strength. The extraordinary high-temperature stability of cold-rolled thin sheets, obtained by the alloy and process design in this study, can be effectively utilized for many light-weight applications of AA3xxx Al alloys.

中文翻译：

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钎焊温度下超薄冷轧 AlScZrMn(Mg) 板中沉淀诱导的再结晶减缓：合金成分和热处理路线的关键影响

摘要 利用先进的电子显微镜技术、析出物/弥散体演化的统计分析和分析研究，我们证明了合金成分（Sc、Mn 和 Mg 含量）和热处理途径（加热速率和预时效）对再结晶的关键影响。 AlScZrMn(Mg) 合金的行为。在热处理的冷轧板（0.3 毫米厚）中发现了两种主要类型的第二相，即 Al3(Sc,Zr) 析出物和 α-Al(Mn,Fe)Si 弥散体。观察到这两种相都与异常大尺寸（分别为 >100 nm 和 >500 nm）的 Al 基体保持相干性，并表现出前所未有的热稳定性水平（即高抗粗化性）。再结晶行为和强度演变被证明是析出物/弥散体的尺寸和空间数密度演变的强函数，而这又受合金成分和热历史控制。特别是，在缓慢升温至 590 °C（AlMn 合金的典型钎焊温度）时，再结晶得到有效缓解，而在较快升温期间发生完全再结晶。这种行为可以通过加热到 590 °C 时在中高温范围内的 Al3(Sc,Zr) 沉淀和再结晶现象的竞争动力学来解释。在快速升温之前，在中间温度范围（即 250–400 °C）内引入预时效处理，由于细分散的 Al3(Sc,Zr) 析出物的大空气数密度的稳定作用，显示可防止再结晶。合金中较高的 Sc 含量增强了这种稳定效果。添加 Mn 不仅增强了再结晶的缓解（通过细化 Al3(Sc,Zr) 沉淀物），而且细化了 α-Al(Mn,Fe)Si 弥散体的演化，从而导致更高的屈服强度。另一方面，添加 Mg 对 Al3(Sc,Zr) 析出物的演化和再结晶状态没有影响，尽管它会导致 α-Al(Mn,Fe)Si 弥散体的细化，从而导致更高的最终屈服强度。通过本研究中的合金和工艺设计获得的冷轧薄板非凡的高温稳定性，