冲击加载下双态组织高强度钛合金的强韧化机理研究

By using the split Hopkinson bar, the transmission electron microscopy and the scanning electron microscopy, we will investigate the role of ageing temperature in the volume fraction and the dimension of strengthening phase, the flow of constitutive phases under dynamic compression, the deformation behavior of constitutive phases in the plastic zone, the initiation and the propagation behavior of cracks in the plastic zone as well as the effect of microstructures and loading rates on the dynamic compression strength and the dynamic fracture toughness for bimodal high-strength titanium alloys, in order to develop a deep understanding on the microstructure evolution, the role of dimension and strain rates on deformation mechanisms of the strengthening phase as well as the dynamic strength-fracture toughness performance of bimodal high-strength titanium alloys. The aim of this project is to find out the main factor that dominates the combination of the dynamic strength and the dynamic fracture toughness and to discover the underlying strengthening-toughening mechanism. Our work may provide a theoretical support on the application of bimodal high-strength titanium alloys in shock resistant structures.

项目利用分离式Hopkinson杆、透射电子显微镜和扫描电子显微镜，通过分析时效温度对双态组织高强度钛合金中强化相体积分数与尺寸的影响，研究合金动态压缩强度和动态断裂韧性对微观结构参数和应变率的依赖性，表征在动态压缩条件下合金各组成相的塑性变形行为，观察塑性区内合金的塑性变形特性、裂纹的起裂与扩展过程，从而掌握双态组织高强度钛合金的微观结构演变规律，认知合金动态强—韧性性能，阐明尺寸和应变率对合金中强化相塑性变形机制的耦合影响规律。项目旨在探明制约双态组织高强度钛合金动态强度—韧性的关键因素，揭示双态组织高强度钛合金的动态强—韧化机理，为合金在抗冲击结构中的服役提供理论支撑。

项目团队利用分离式Hopkinson杆、透射电子显微镜和扫描电子显微镜，分析了时效制度对双态组织Ti-5553钛合金中强化相体积分数与尺寸的影响，研究了合金动态压缩强度和动态断裂韧性对微观结构参数和应变率的依赖性，探明了动态压缩条件下合金各组成相的塑性变形行为，阐明了塑性区内合金的塑性变形特性、裂纹的起裂与扩展过程，揭示了双态组织高强度钛合金的动态强—韧性性能，尺寸和应变率对合金中强化相塑性变形机制的耦合影响规律。项目探明了制约双态组织高强度钛合金动态强度—韧性的关键因素，研究了双态组织高强度钛合金的动态强—韧化机理，为合金在抗冲击结构中的服役提供理论支撑。