多元复合微合金化协同作用下双辊铸轧6xxx系铝合金组织演变及增强增塑机理研究

铝合金薄板短流程生产制备技术是一种技术含量高、装备集成度强、生产工艺水平高的铝合金板带先进制造技术，但我国以双辊铸轧技术制备的6xxx系铝合金板材存在组织不均、成形性差及强塑性差等问题。鉴于此，本项目提出了利用多元复合微合金化形成L12结构的纳米复合相协同改善6xxx系铝合金铸轧板材的微观组织结构，提高板材综合性能的研究思路。但是当前，在铸轧铝合金成形过程中多元复合微合金元素之间的交互作用及其对L12结构纳米复合相析出行为的影响机理尚不明晰。本项目拟通过添加多元复合微合金元素，结合有限元模拟、性能测试、组织观察等手段系统研究6xxx系铝合金铸轧过程中多种微合金元素之间的交互作用，揭示L12结构纳米复合相的析出行为，阐明L12结构纳米复合相特征与板材强塑性的相关性。本研究可以为我国生产出高质量的6xxx系铝合金铸轧板材提供科学基础和实验依据。

Short-flow production and preparation technology of aluminum alloy sheet is an advanced manufacturing technology of aluminum alloy sheet and strip with high technical content, strong equipment integration and high production technology level. However, the 6XXX series aluminum alloy sheet prepared by the twin-roll casting and rolling technology in China still has some problems such as uneven structure, poor formability and poor strong plasticity. In view of this, this project put forward the research idea of improving the microstructure and comprehensive properties of 6XXX series aluminum alloy cast-rolled sheet by using the nano-composite phase with L12 structure formed by multi-component composite microalloying. However, at present, the interaction between multiple composite microalloying elements and its influence mechanism on the precipitation behavior of L12 structure composite phase in the casting and rolling aluminum alloy forming process are not clear. This project intends to through the composite micro alloy elements, combined with the finite element simulation, the performance test, microstructure observation system research in 6 XXX series aluminum alloy cast-rolling process of the interaction between multiple microalloy element, reveal L12 nanocomposite phase separation behavior of structure, clarify L12 structure characteristic and the sheet strong plasticity. This study can provide scientific basis and experimental basis for the production of high quality 6XXX series aluminum alloy cast-rolled sheet in China.