铝锂合金微塑性成形过程中不规则流动行为的初始组织依赖性研究

Aiming at basic scientific issues in microforming of aluminum-lithium alloy, the genetic effects decided by structure and orientation of the precipitated phase will be studied, meanwhile, the influence of grain evolution and microstructural evolution behaviors on the material flow Stress will be also extensively investigated. The stress response constitutive model containing microstructure evolution will be established, and the genetic effects determined by the structure and orientation of precipitated phase will be revealed. Furthermore, the influencing mechanism of grain evolution behavior and the generated anisotropy will be defined, and the mapping relation between material flow behavior and precipitated phase strengthening as well as grain boundary strengthening will be quantitatively reproduced. Additionally, the correlation between original structure, forming process and forming precision will be explored, then the scientific principles for optimizing material flow behavior and improving forming quality will be proposed. The project combines precipitation growing, grain deformation, dislocation slip and material flow with micro-scale plastic deformation and advanced simulation methods. The interactive effects between micro/nano-scaled genetic effect, meso-scaled size effect and macro-scaled rheological behavior will be systemtically studied considering the scientific issues extracted from the application background of controlling structure, controlling property, controling shape in microforming process. This project shows novel subject and clear application background, which can provide a theoretical model for integration design of precise controlling shape and controlling property in micro-scale plastic deformation.

针对铝锂合金微塑性成形过程中的基础科学问题，开展微塑性成形过程中析出相结构及取向决定的遗传效应研究、微塑性成形过程中晶粒演化行为研究和特征微结构演变行为对材料流变应力影响研究，建立包含特征微结构演变的应力响应本构关系模型，揭示微塑性成形过程中析出相结构及取向决定的遗传效应，明晰晶粒演变行为及产生的各向异性的影响机制，定量再现材料流动行为与析出相强化、晶界强化之间的映射关系，明晰初始组织—成形工艺—成形精度之间的关联，提出优化材料流动行为、提高成形质量的科学原则。本项目将沉淀析出与长大、晶粒变形与位错滑移、材料流动与零件微塑性成形和先进模拟方法的相结合，从微塑性成形工艺的控构、控性、控形应用背景中凝练出的科学问题，研究纳观尺度上的遗传效应、细观尺度上的尺寸效应以及宏观尺度上的流变行为的交互影响，立体新颖，应用背景明确，可为微塑性成形的精确控形、控性的一体化设计提供理论支撑

本课题针对铝锂合金微塑性成形过程中的基础科学问题，系统开展了微塑性成形过程中晶粒演化行为研究和特征微结构演变行为对材料流变应力影响研究，建立了包含特征微结构演变的应力响应本构关系模型，明晰了晶粒演变行为及产生的各向异性的影响机制，定量表征了材料流动行为与微观组织之间的关系，提出了优化材料流动行为、提高成形质量的科学原则，建立了成形极限理论模型可对其成形极限进行理论预测，为微塑性成形的精确控形、控性的一体化设计提供理论支撑。