基于激光近净成形方法的多维度金属/陶瓷功能梯度材料制备基础

As the requirements of the aerospace strategic equipment components used in a variety of extreme environment are increasing, the performance of a single material in the diverse environments is difficult to satisfy the special requirements. Metal/ceramics Functionally Graded Materials (FGM) take account of the excellent characteristics of ceramic and metal and shows the significant application value in the extremely harsh diversified environments. Consequently, the manufacturing of metal/ceramics FGM influences the manufacturing level of the future strategic equipment. In this project, with the goal of Laser Engineered Net Shaping of multi-dimensional metal/ceramic FGM and aiming at solving the complex problems of the high stress in the forming process, the forming defects easily and the complex interaction mechanism between different graded layers, it is to establish the stress coupling model of outfield controlling, and then based on the stress control under the outfield intervention condition and the compatibility rule in the time-space domain, a method of Laser Engineered Net Shaping is proposed. On this basis, it is to research the defects forming and extension mechanism in the multi-dimensional metal/ceramic FGM and put forward a defect suppression technology to explore the forming mechanism of metal/ceramic FGM by Laser Engineered Net Shaping. The Laser Engineered Net Shaping, which is based on the stress control and the compatibility rule, can not only achieves the manufacturing of multi-dimensional complex metal/ceramic graded parts, but also expands the application fields of metal/ceramic FGM and makes the replacement of metal/ceramic coating by the complex metal/ceramic graded parts be possible.

随着航空航天重大战略装备零部件在多种极端环境下的使用需求不断增加，单一材料在多元化特种环境下的性能已经难以满足要求。而金属/陶瓷功能梯度材料（FGM）兼顾了陶瓷和金属优良特性，在极度恶劣的多元化环境中已显示出巨大应用价值，其制备技术影响着未来战略装备的制造水平。本项目以激光近净成形多维金属/陶瓷FGM为目标，针对成形过程高应力、易生缺陷、不同梯度层间相互作用机制复杂等难题，建立外场调控条件下应力耦合特征模型，提出以外场干预的应力调控为基础和以时空域相容性规律为原则的激光近净成形方法，在此基础上研究多维度金属/陶瓷FGM制备过程缺陷产生扩展机理，提出缺陷抑制方法，探索激光近净成形过程金属/陶瓷FGM成形机制。基于应力调控和相容性规律的激光近净成形方法不仅可以实现多维复杂金属/陶瓷FGM制备，而且拓展了金属/陶瓷FGM的应用领域，使特种环境下复杂金属/陶瓷梯度零件替代金属/陶瓷涂层成为可能。

本项目以激光近净成形多维度FGM 为研究对象，针对金属/陶瓷 FGM 激光近净成形制备过程的要求，研究了多维度激光近净成形过程金属/陶瓷 FGM 应力场调控机理和时空域相容性规律，提出了基于外场干预的激光近净成形过程 FGM 应力控制策略及以 FGM 性能控制为目标的激光近净成形方法，为解决多维度金属/陶瓷 FGM 的快速直接制备及缺陷控制提供了理论依据。.主要研究内容及进展：提出了多维度功能梯度叶片应力调控方法，实现了SS316/Ni20/Fe90三元功能梯度叶片的激光近净成形；提出了基于超声辅助的TC4/ZrO2成分分布梯控策略，实现了梯度涂层的制备； 揭示了成形结构表面缺陷形成规律，提出了基于表面缺陷控制的工艺优化方法，初步实现了TC4/ZrO2梯度滑轨的成形制造。共发表论文16篇，其中SCI/EI收录15篇；授权发明专利12项，申请发明专利14项；协助培养已毕业博士1名，硕士3名；参与本课题博士后1名，博士研究生1名，硕士研究生1名。.主要结果：提出了基于基板预热和成分优化控制的梯度结构开裂抑制方法，实现了SS316/Ni20/Fe90功能梯度薄壁结构成形，获得形貌良好无宏观缺陷的成分梯度薄壁结构；实现了基于超声辅助的梯度涂层元素分布控制，表明了超声辅助条件下梯度涂层元素分布可以实现可控化设计。.科学意义：本项目的研究可以为金属/陶瓷 FGM 直接制造提供了一种新思路，可实现复杂金属/陶瓷 FGM 的制备，拓展了金属/陶瓷 FGM 的应用领域，使得金属/陶瓷 FGM 的价值进一步提升，特别是对航空航天极端使役要求零件的设计制造提供了一种切实可行的技术方案。在理论上本项目的研究完善了金属/陶瓷 FGM 的成形机理，在工程应用领域使得金属/陶瓷功能梯度零件在多元特种环境下替代金属/陶瓷涂层已经成为可能。