高频微振复合激光焊热-力学效应及接头多尺度疲劳损伤机理

项目名称： 高频微振复合激光焊热-力学效应及接头多尺度疲劳损伤机理

项目编号： No.51305253

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 机械、仪表工业

项目作者： 卢庆华

作者单位： 上海工程技术大学

项目金额： 25万元

中文摘要： 核级设备中使用的Ni基高温合金焊接构件由于工作环境恶劣，构件的安全性和可靠性问题尤为突出。针对Ni基高温合金焊接接头组织粗大、裂纹敏感性高这一突出问题，提出高频微振复合激光焊接新技术，实现Ni基高温合金激光焊过程中振动和焊接工艺参数协调控制，建立能量调控优选准则。通过研究高频微振复合激光焊接过程熔池温度场和熔体行为，深化基于能量调控的激光焊接动态过程的认识，探析热-力学效应对接头成形的影响机制。研究不同尺度的接头疲劳损伤产生、扩展和演化规律，通过细观力学有限元分析，建立三维精细化损伤演化模型，掌握接头疲劳损伤机理，结合接头性能分析结果，揭示高频微振复合焊接工艺参数与疲劳损伤演化的内在关联。本项目的研究成果可为Ni基高温合金在特种工程焊接结构中安全可靠的长期运行奠定理论和技术基础。

中文关键词： 高频微振；激光焊接；微观机制；疲劳性能；

英文摘要： The safety and reliability of Ni-based superalloy welding structures used in nuclear level devices are particularly prominent because of the bad serviced environment. The new technology of laser/high-frequency micro-vibration hybrid welding is adopted to solve the outstanding problems of coarse grains and high crack sensitive in Ni-based superalloy welding. The coordinated control of vibration welding process parameters and the optimization of energy regulation will be achieved. By studying the molten pool temperature field and melt behavior of laser/high-frequency micro-vibration hybrid welding, the dynamic process of the laser welding based on energy regulation will be understood deeply and the mechanism of thermodynamic effect on joint forming will be explored. Multi-scale fatigue crack initiation, propagation and evolution rule will be investigated. A three-dimension refined simulation model will be developed to predict the damage behavior of welded joint through the meso-mechanics finite element analysis. The joint fatigue damage mechanism will be researched to reveal the internal relationship of laser/high-frequency micro-vibration hybrid welding process parameters and fatigue damage evolution. This project will provide a theoretical and technical basis for the applications of Ni-based superalloy in specia

英文关键词： high-frequency micro-vibration；laser welding；micromechanism；fatigue property；