航天铝锂合金大型环件构筑热轧成形技术基础研究

To satisfy the light weight and large scale requirement of aerospace equipment, large and high performance aluminum-lithium alloy ring components should be developed. However, the traditional large ring rolling method which rolls a large ring by a large ingot is difficult to manufacture large and high performance aluminum-lithium alloy ring. So this project proposed a novel constructive hot ring rolling method which rolls a large ring by some small ingots to manufacture large and high performance aluminum-lithium alloy ring. It aims to solve the key scientific problems of constructive hot ring rolling for large aluminum-lithium alloy ring. To determine the scope of the material hot deformation condition, hot deformation and microstructure evolution behavior of aluminum-lithium alloy are to be researched. Based on the study of the interface evolution behavior and microstructure evolution rule during constructive hot ring rolling for aluminum-lithium alloy ring, the interface coalescence mechanism and the regulation mechanism of ring microstructure and property are to be clarified. Further studies are done to build the interface coalescence condition and the ring microstructure and property control method of constructive hot ring rolling for aluminum-lithium alloy ring. Finally, the optimized forming theory and technology design method of constructive hot ring rolling for aluminum-lithium alloy ring are established. The study can provide a new method and corresponding theoretical support for large and high performance aluminum-lithium alloy ring components manufacturing, which can raise the manufacture level of high performance and large scale aerospace ring components.

为满足航天装备轻量化和大型化发展需求，亟需研制高性能铝锂合金大型环类构件。但由大铸锭成形大环件的传统轧制技术难以解决高性能铝锂合金大型环件制备问题，本项目提出以小铸锭成形大环件的构筑热轧成形新技术来制造高性能铝锂合金大型环件。围绕铝锂合金大型环件构筑热轧成形关键科学问题，研究铝锂合金热变形和组织演化行为，确定材料热变形条件范围；揭示铝锂合金环件构筑热轧过程界面演化行为和和环件组织性能演化规律，阐明其界面愈合机制和成形环件组织性能调控机理，确定界面愈合条件和环件组织性能调控方法；建立高性能铝锂合金大型环件构筑热轧优化成形理论与技术设计方法。该研究可为高性能航天铝锂合金大型环件制造提供新的技术方法和理论支撑，提高我国高性能航天大型环形构件制造水平。

本项目紧密结合我国航天高性能轻质大构件自主制造重大需求，针对航天铝锂合金大型环件制造关键问题，突破大铸锭轧制成形大型环件的传统技术思路，提出由小铸锭构筑热轧成形大型环件的新技术。通过理论分析、数值模拟、缩比轧制实验、组织性能测试等手段，围绕铝锂合金大型环件构筑热轧成形关键科学问题开展探索研究。研究了材料构筑热变形过程界面愈合行为，揭示了预连接条件、变形温度、变形量、保温时间等关键工艺条件对构筑热变形界面愈合的影响规律，阐明了构筑热变形过程界面愈合机制；研究了环件构筑热轧过程变形行为，揭示了轧制温度、进给速度等热轧变形条件和环坯构筑方式对环件成形质量影响规律，开发了环件构筑热轧成形工艺方法；提出了材料构筑界面和成形组织状态的电冲击调控技术方法，揭示了电冲击预处理对材料构筑界面愈合能力的促进作用，以及电冲击后处理对材料成形微纳缺陷的修复作用；形成了高性能铝锂合金大型环件构筑热轧优化成形理论与技术设计方法。研究成果可为高性能铝锂合金大型环件制造关键技术提供重要科学依据，在航天、核电、石化、重型机械等重要领域用高性能超大环形构件制造方面具有较好的应用前景。