Laser Peen Bending: Simultaneous Shaping and Property Enhancement

激光喷丸弯曲：同时成形和性能增强

• 批准号: 0620741
• 负责人: Y Lawrence Yao
• 金额: $ 30.04万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0620741&HistoricalAwards=false
• 关键词: Laser; Peen; Bending; Simultaneous; Shaping

Micro scale laser peen bending (LPB) combines the fatigue performance enhancement effects of laser shock processing with a controlled bending deformation to shape micro scale metallic parts without hard tooling nor external forces. Process conditions under which compressive residual stress is generated at both the irradiated and opposite surfaces of the target will be better understood. Interactions between residual stress generation and bending mechanism will be investigated. The anisotropic behavior of the material and the length scale effect on material properties will be considered since the laser-material in teraction zone is in the same order of magnitude as material grain size. Single crystal FCC metals (Al and Cu) will be used to investigate the anisotropic material response. Spatially resolved characterization of induced residual stresses will be carried out using X ray micro diffraction techniques, and the degrees of plastic deformation and geometrically necessary dislocation (GND) distributions will be measured by Electron Backscatter Diffraction (EBSD). These results will be used to validate the modeling and simulation efforts, in which, an explicit finite element analysis for shock dynamic effects on single crystals will be developed, based on meso-scale single crystal plasticity incorporating the pressure dependent elastic moduli and dynamic hardening caused by length scale.The established principles including anisotropy, hardening from length scale, and process dynamics, and developed techniques for LPB can be extended to other micro-scale manufacturing processes. Expected results will help micro manufacturing processes to make higher quality micro components more effectively and flexibly. The significantly improved understanding of process capability and limitations will open up opportunities for new micro part designs. Personnel development and dissemination of results will improve national competitiveness in micro manufacturing.

微尺度激光喷丸弯曲（LPB）结合了激光冲击处理的疲劳性能增强效应和受控的弯曲变形，以在没有硬工具或外力的情况下成形微尺度金属零件。将更好地理解在靶的辐照表面和相对表面处产生压缩残余应力的工艺条件。将研究残余应力产生和弯曲机制之间的相互作用。 由于激光与材料相互作用区中的材料与材料的晶粒尺寸处于同一数量级，因此将考虑材料的各向异性行为和材料性质的长度尺度效应。 单晶FCC金属（Al和Cu）将用于研究各向异性材料响应。诱导残余应力的空间分辨表征将使用X射线显微衍射技术进行，塑性变形和几何必要位错（GND）分布的程度将通过电子背散射衍射（EBSD）测量。这些结果将被用来验证建模和模拟工作，其中，冲击对单晶的动力学效应的显式有限元分析将基于介观尺度的单晶塑性，包括压力相关的弹性模量和长度尺度引起的动态硬化。所建立的原理包括各向异性，长度尺度硬化和过程动力学，并且LPB的开发技术可以扩展到其他微尺度制造工艺。 预期结果将有助于微制造工艺更有效和灵活地制造更高质量的微部件。对工艺能力和局限性的理解的显著提高将为新的微型零件设计提供机会。人才培养和成果传播将提高国家在微型制造业的竞争力。