超瞬态凝固增材制造航空发动机功能梯度材料的基础研究

Multi-material and functionally-graded component realizes its property grads by spatial arrangement of different microstructure and grain morphology with the same material, and it has important application prospects in many fields, such as aerospace, defense, military and biological medicine. At present, it is difficult to realize the locally spatial customization of microstructure and property of the multi-material and functionally-graded component using traditional processing methods. This project, breakthrough the limitation of traditional continuous-wave laser processing methods, proposes hyper-transient solidified laser processing method regulated under composite energy field to dynamically excite the molten pool for tailoring the microstructure and property of the component. The mathematical model is established to study dynamic fluctuation laws of molten pool and their influence mechanisms on solidification microstructure. The processing windows are optimized during hyper-transient solidified laser additive manufacturing. The critical transformation process parameters are determined. The mapping relationship between target microstructures and process parameters is obtained. The multi-material and functionally-graded component can be directly manufactured using the customized processing route. This project will enrich the non-equilibrium rapid solidification theory and provides theoretical and experimental basis for direct laser manufacturing of milti-material and functionally-graded components. Simultaneously, it also will improve the design freedom of heterogeneous and functionally-graded components to realize the design and manufacturing of functionally-graded components with more freedom.

多质异性功能梯度构件通过多种材料不同组织形态的空间布局实现其梯度性能，在航空航天、国防军工及生物医疗等领域具有重要应用前景。目前，采用传统加工方法难以实现此类功能梯度构件组织及性能的定制化制造。本项目突破传统连续激光增材制造思路，提出采用复合能场调控的超瞬态凝固增材制造实现凝固组织及性能的微观精确调控和宏观订制化布局。本项目拟通过建立复合能场调控的超瞬态凝固增材制造三维模型，结合实验观测与表征手段，揭示复合能场激励对熔池凝固条件作用机理，和对凝固组织的影响机理；通过优化超瞬态凝固光增材制造复合能场激励参数，探寻动态激励下凝固组织转变临界参量，获得目标组织性能与工艺参数的映射关系；通过定制化的工艺设计实现多质异性功能梯度构件的直接激光制造。本项目将丰富与发展非平衡快速凝固理论，为实现多质异性功能梯度构件的直接激光制造提供重要理论及实验依据，实现更大自由的功能梯度构件设计与制造。

多质异性功能梯度构件通过多种材料不同组织形态的空间布局实现其梯度性能，在航空航天、国防军工及生物医疗等领域具有重要应用前景。本项目提出采用复合能场调控的超瞬态凝固增材制造实现凝固组织及性能的微观精确调控和宏观订制化布局。通过建立磁场与准连续激光激励下的超瞬态凝固增材制造三维模型，获取磁场与准连续激光激励下熔池动态固液界面关键特征及演变规律，结合相应实验观测与表征，揭示外加能场场激励特征参量对熔池动力学影响机理。通过复合加工策略实现了微观组织的区域订制，进一步的机械性能研究表明打印件织构强弱是决定室温拉伸断裂行为的重要因素。通过热力学计算探究了梯度界面上的相形成与合金成分的内相关机制，提出基于热力学计算的梯度界面优化方法，并通过实验验证了方法的可行性。本项目丰富与发展了外场激励下的激光增材制造理论，为实现多质异性功能梯度构件的直接激光制造提供了重要理论及实验依据。