Ti2AlNb基合金组织演变特征及其对损伤容限性能的影响

项目名称： Ti2AlNb基合金组织演变特征及其对损伤容限性能的影响

项目编号： No.51464035

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 矿业工程

项目作者： 王克鲁

作者单位： 南昌航空大学

项目金额： 50万元

中文摘要： 根据Ti2AlNb基合金的成形特点，以微观组织、可加工性能及损伤容限性能为控制目标，采用修正的动态材料模型、极性交互模型、数值模拟并结合物理模拟的方法对微观组织演变特征和缺陷形成及变化规律进行预测和控制，掌握不同变形条件下的塑性变形机制；揭示多场耦合作用下组织及缺陷的形成和变化规律，并构建组织演变和缺陷形成的热力学和动力学模型。采用宏观试验和微观分析相结合的办法，系统研究Ti2AlNb基合金的损伤容限性能，分析不同微观组织对损伤容限性能的影响规律，建立断裂韧性、裂纹扩展速率及裂纹扩展门槛值的定量模型，最终确定出变形工艺参数-功率耗散效率-微观组织（含缺陷）-损伤容限性能之间的定性和定量关系，获得优化的变形工艺参数范围，实现性能设计与工艺设计的一体化。研究结果可为Ti2AlNb基合金复杂构件精确成形及微观组织和损伤容限性能的精确控制提供理论基础。

中文关键词： Ti2AlNb基合金；组织演变；损伤容限；动态材料模型；数值模拟

英文摘要： Based on plastic deformation characteristics of Ti2AlNb-based alloy, and on the control target of microstructure, processability and of damage tolerance properties, through the prediction and control of characteristics of microstructural evolution and of principles of defects formation and evolution, by using a method of combination of a modified dynamic material model and numerical simulation and physical simulation, the microstructural characteristics and plastic deformation mechanism under different deformation conditions are obtained. The formation and evolution mechanism of defects and microstructure under coupled multi-field condition is disclosed. And the thermodynamics model and the kinetics model are also constructed for describing microstructure evolution and defect formation. The damage tolerance behavior of the Ti2AlNb-based alloy is systematically studied and evaluated by using a combined method of macroscopic experiment and microcosmic analysis. The influence of different deformed microstructure on damage tolerance properties is analyzed. And the quantitative models of fracture toughness, crack growth rate and the threshold value of crack propagation were established. On the base of the above, the qualitative relationship and quantitative relationship among deformation parameters of the Ti2AlNb-based alloy, efficiency of power dissipation, microstructure characteristics and defect, damage tolerance properties will be obtained. This can realize the integration of properties design and process design. The research results can provide the theoretical basis of the precise formation of complex components based on Ti2AlNb-based alloy, and of the precise control of microstructure and damage tolerance properties.

英文关键词： Ti2AlNb-based alloy;Microstructure evolution;Damage tolerance;Dynamic materials model;Numerical simulation