电流辅助Ti2AlNb合金多位加载柔性介质拉/胀复合超塑变形机制及电致多重效应研究

The long time usage temperature of Ti2AlNb alloy can reach 800 ℃. Hence, it meets the urgent needs of China's new generation of high-speed sonic aircraft to improve the Mach number and increase the flight distance. It is well known the superplastic forming of Ti2AlNb alloy is a near net forming technique to solve the problem of difficult deformation of intermetallic compound. However, the coarse and local thinning of has seriously affected the mechanical properties of the superplastic formed components and it cannot meet the“shape controlling”and“performance controlling” of the double requirements, resulting in a bottleneck to be solved. The novel idea of this program lies in proposing the current assisted drawing combined bulging superplastic forming technology of Ti2AlNb alloy with multi-position loading flexible medium. Accordingly, the coordination superplastic deformation of the material under the combined effect of electric, thermal and force is highly emphasized in the research. Both microscopic and macroscopic action mechanism of pulse current and drawing combined bulging superplastic deformation with flexible medium will be determined. Meanwhile, the current-assisted superplastic deformation behavior and the electro-induced multiple effects of Ti2AlNb alloy will be revealed. The research will also investigate of superplastic deformation of Ti2AlNb alloy, thereby figuring out microscopic and macroscopic mechanism of pulse current with superplastic deformation. And the deformation behavior of the material during the multi-position loading flexible medium superplastic forming will be revealed. The effect of current and multi-position loading on microstructure evolution will be identified, thereby the collaborative control method will be grasped. Hence, the microstructure and properties of Ti2AlNb alloy after superplastic deformation will be improved, the problem of shape controlling and microstructure controlling of complex components will be solved.

Ti2AlNb合金可在800℃长时使用，符合我国新一代高倍音速飞行器提高马赫数和增加飞行距离的迫切需求。Ti2AlNb合金超塑成形是解决金属间化合物难变形问题的近净成形技术，但成形后晶粒粗大和局部过度减薄，严重影响成形构件的力学性能，难以满足“控形”和“控性”的双重要求，这一瓶颈问题有待解决。本项目首次提出电流辅助Ti2AlNb合金多位加载柔性介质拉/胀复合超塑成形技术，电、热、力三场综合作用下材料的协调变形机制是研究的重点，电流与拉/胀变形作用下材料的宏微观作用机制是需明确的科学问题。研究将揭示Ti2AlNb合金电流辅助超塑性变形特征及电致多重效应，揭示电流对Ti2AlNb合金超塑性变形宏微观作用机理，解明多位加载下材料拉/胀复合快速超塑变形机制，揭示电流及拉/胀变形对材料微观组织演变的综合作用机制，掌握协调控制方法，提升Ti2AlNb合金构件超塑变形后的组织与性能，解决控形控性难题。

Ti2AlNb合金可在800℃长时使用，符合我国新一代高倍音速飞行器提高马赫数和增加飞行距离的迫切需求。Ti2AlNb合金超塑成形是解决金属间化合物难变形问题的近净成形技术，但成形后晶粒粗大和局部过度减薄，严重影响成形构件的力学性能，难以满足“控形”和“控性”的双重要求，这一瓶颈问题有待解决。本项目首次提出电流辅助Ti2AlNb合金多位加载柔性介质拉/胀复合超塑成形技术，电、热、力三场综合作用下材料的协调变形机制是研究的重点，电流与拉/胀变形作用下材料的宏微观作用机制是需明确的科学问题。研究将揭示Ti2AlNb合金电流辅助超塑性变形特征及电致多重效应，揭示电流对Ti2AlNb合金超塑性变形宏微观作用机理，解明多位加载下材料拉/胀复合快速超塑变形机制，揭示电流及拉/胀变形对材料微观组织演变的综合作用机制，掌握协调控制方法，提升Ti2AlNb合金构件超塑变形后的组织与性能，解决控形控性难题。