新型钛锆基合金的多级结构调控及强韧化技术研究

TiZr-based alloys, which possess low density, high strength (high specific strength), good thermal stability as well as high-energy particle radiation resistance, become the most application prospect of a new generation of aerospace structural material. Thus, development of new high-performance TiZr-based alloys and corresponding industrial preparative techniques has very important theoretical and applied value for promoting the aerospace business. The main purpose of this issue is to study the preparative techniques of new TiZr-based alloys with hierarchical structure and its structural evolution, based on the plastic deformation and solid phase transformation theories. The concrete work is to reveal the evolution rules and the deformation mechanism of the multi scale grain, the dislocation density in different areas and the crystal orientations, to discuss the relationship between the phase transformation and substructure evolution of TiZr-based alloys in the subsequent aging process, to clarify the relationship between the hierarchical structure and mechanical properties and the performance control principle, and finally to optimize the characteristic parameter of the hierarchical structure. The findings will realize the controllable preparation of high-performance TiZr-based alloys with hierarchical structure as structural materials possessing industrial application value, enrich the basic theory of the microstructure evolution of TiZr-based alloys, and provide the theoretical foundation and technique support for the preparation and application of new aerospace structural materials.

TiZr基合金具有密度低、强度高（高比强度）、热稳定好以及耐高能粒子辐射等优异性能，是极具应用前景的新一代航空航天结构材料。因此，发展高性能的、具有工业应用前景的TiZr基合金及其制备技术，对推动我国航空航天事业的发展具有重要的理论价值和实际应用意义。本课题基于钛合金塑性变形和固态相变理论，主要研究TiZr基合金多级结构的演化规律和制备技术；揭示新型TiZr基合金塑性变形中的多尺度晶粒、不同区域位错密度及晶体取向的演变规律和变形机制；探讨TiZr基合金在后续时效过程中的相结构转变与亚结构演变的关联性；阐明多级结构与性能的关系和宏观性能的调控原理，优化多级结构的特征参数。通过发展高性能多级结构材料的制备技术及强韧化工艺调控，实现具有工业应用价值的高性能TiZr基合金多级结构的可控制备，丰富TiZr基合金材料微观组织演化的基础理论，为新型航空航天结构材料的制备和应用提供理论依据和技术支撑。

高性能TiZr基合金是极具应用前景的新一代航空航天结构材料，发展高性能的、具有工业应用前景的TiZr基合金及其制备技术，对推动我国航空航天事业的发展具有重要的理论价值和实际应用意义。本项目采用非自耗电弧熔炼制备不同成分的TiZr基合金，并基于塑性变形理论和固态相变理论，研究了TiZr基合金多级结构的演化规律和制备技术；揭示出新型TiZr基合金塑性变形中的多尺度晶粒、不同区域位错密度及晶体取向的演变规律和变形机制；探讨了TiZr基合金在后续时效过程中的相结构转变与亚结构演变的关联性；阐明了多级结构与性能的关系和宏观性能的调控原理，优化多级结构的特征参数。. 通过大量研究，制备出具有高强度的TiZr基合金体系，其抗拉强度超过1400MPa，延伸率大于5%；部分TiZr合金具有良好的生物医用前景。通过发展高性能多级结构材料的制备技术及强韧化工艺调控，实现具有工业应用价值的高性能TiZr基合金多级结构的可控制备，并丰富TiZr基合金材料微观组织演化的基础理论，为新型航空航天结构材料的制备和应用提供理论依据和技术支撑。