箔板复杂曲面微结构阵列软模微胀形尺度效应及增塑机理

Complex curved micro-sheet feature array is one of essential parts for protecting micro target in inertial confinement fusion. This kind of part is manufactured using micro-machining and electroplating process. The manufacture efficiency and qualification rate of parts are both very low, which restricts the development of investigation of inertial confinement fusion. Then, the ultrasonic assisted micro-bulging using soft punch is carried out to break through the bottleneck problem in manufacturing and assembling of complex curved micro-feature array mold. At the same time, “Blaha effects” and surface effects of ultrasonic vibration are used to improve the micro-sheet bulging formability. Experiments of ultrasonic assisted micro-bulging using soft punch will be performed to study key scientific problems such as the coupling mechanism of “Blaha effects” and size effects in micro-bulging, microstructure evolution of sheet and improvement of ductility. Considering the acoustic energy, normalization model of flow stress will be developed in ultrasonic assisted micro-sheet forming. FEM simulation and experiments will be used to investigate the ultrasonic assisted micro-bulging using soft punch of complex curved micro-feature array, and to reveal its mechanism. Finally, the complex curved micro-feature array with high quality will be accurately formed. It will promote the wide application of micro-feature parts in national economy and defense fields, which has important practical value and scientific significance.

箔板复杂曲面微结构阵列件是惯性约束聚变微靶防护等急需的核心构件之一，目前采用微细铣削、电镀等复合工艺制造，制造效率和合格率极低、成本非常高，严重制约了惯性约束聚变研究的开展。为此，本项目提出超声辅助软模微胀形工艺，突破复杂曲面微结构阵列模具制造与装配等瓶颈问题，利用超声振动“Blaha效应”和表面效应，提升箔板微胀形成形能力。开展超声辅助软模微胀形实验研究，拟解决超声“Blaha效应”和微胀形尺度效应耦合作用机制、箔板微观组织演变机理以及微胀形增塑机理等关键科学问题，考虑超声能量等，构建超声辅助箔板流动应力归一化模型，开展箔板复杂曲面微结构阵列超声辅助软模微胀形过程数值模拟和实验研究，揭示复杂曲面微结构超声辅助软模微胀形机理，实现高质量箔板复杂曲面微结构阵列的精密成形，促进其在国民经济和国防领域的广泛应用，具有重要的实用价值和科学意义。

本项目针对惯性约束聚变微靶件、质子交换膜氢燃料电池金属极板等箔板复杂曲面微结构阵列制造难题，开展了超声振动辅助胀形尺度效应和增塑机理研究。研制了超声振动辅助微结构胀形等装置，开展了箔板塑性变形行为、成形极限等研究，揭示了超声振幅、尺寸效应等箔板胀形行为耦合机理；基于金属材料位错发射机理，推导了考虑超声场能量的Hall-Petch斜率模型，发现超声振动能够增大成形中n值、r值，即提高了箔板均匀塑性变形能力，并从应变分布、微观亚结构演变角度进行了理论研究，揭示了超声振动辅助箔板增塑机理；进而，开展了箔板复杂曲面微结构超声辅助胀形有限元仿真和实验研究，发现超声振动能够显著增加微结构深度、减小回弹，提升成形轮廓精度，壁厚均匀性更好，制备出了满足激光聚变微靶件、氢燃料电池金属极板等合格的箔板微结构件。发表学术论文10篇，其中在IJP、JMPT等顶级期刊发表SCI论文8篇，申请发明专利8项、获得授权国家发明专利1项，培养研究生5名，参加国内外学术会议6次，获省级科技奖励2项。项目负责人入选“江苏特聘教授”人才项目。圆满完成了项目任务书规定的研究目标。