激光增材制造中金属熔池固液耦合机制及材料热力本构关系

项目名称： 激光增材制造中金属熔池固液耦合机制及材料热力本构关系

项目编号： No.61475117

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 雷剑波

作者单位： 天津工业大学

项目金额： 80万元

中文摘要： 激光增材制造过程中金属熔池存在能量、动量和质量传输物理行为，直接影响零件精度、变形与裂纹。 通过激光与材料相互作用研究，分析材料光热辐射数理模型，通过光栅光谱实验检测，研究其随波长、温度、发射率等变化规律，建立熔池传热数学物理模型，分析熔池表面温度与内外传热、传质、对流关系。 开展SHPB实验，建立材料应力应变曲线，构建其动态本构关系，分析激光增材制造零件变形机制及其动态力学行为，为零件材料及工艺选择提供依据；分析零件裂纹形成、成核与长大效应，探讨热冲击对损伤发展的影响机理。 有望在材料光热辐射与材料热力耦合本构关系方面取得理论突破，研制出激光增材制造材料光热辐射检测系统，建立基于SHPB实验的激光增材制造材料本构测试与分析方法，建立材料应力应变曲线和裂纹分类数据库，探索激光增材制造中光热辐射规律和结构变形破坏的新现象和新机理。

中文关键词： 激光技术；激光熔覆；增材制造；激光熔池

英文摘要： There is transmission of energy, momentum and mass in laser molten pool, which would affect the parameters of precision, deformation and crack in laser additive manufacturing. In order to study materials photothermal radiation, the relationship with wavelength, temperature,emissivity would be analyzed by grating spectrum technology.The heat transmission model woud be set up to research the relationship between laser molten pool temperature and its heat exchange, convection and mass exchange. The deformation law and material dynamic constitutive relations in different directions will be investigated in SHPB experiments. Mechanism of material distortion, crack nucleation, growth effect and thermal shock on the development of material damage can be developed by the relationship between stress and strain. Theoretical breakthroughs are expected to be achieved in materials photothermal radiation and thermal-mechanical coupling constitutive model. Based on the established elasto-plastic constitutive relations with damage, damage evolution equation and crack criterion, the theoretical thermal-mechanical coupling constitutive model will be constituted. Some new phenomena and mechanism on photothermal radiant laws and structure deformation damage will be achieved by studying the stress-strain effect and crack formation and evolutionary mechanisms of component material in laser additive manufacturing.

英文关键词： Laser technique;Laser cladding;Additive manufacturing;Laser molten pool