旋转磁场下钛合金激光沉积层组织演变规律研究

项目名称： 旋转磁场下钛合金激光沉积层组织演变规律研究

项目编号： No.51305280

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： 杨光

作者单位： 沈阳航空航天大学

项目金额： 26万元

中文摘要： 激光沉积制造技术在航空发动机钛合金整体叶盘、机匣、加强框等航空关键零件的制造中有着广阔的应用前景。但在激光沉积过程中，材料的熔化、凝固和冷却都是在极快条件下进行，致使零件质量和综合力学性能难以实现精确控制。本项目提出旋转磁场辅助钛合金激光沉积修复技术，即利用电磁搅拌能引起激光熔池内特定运动规律的混合对流，从而加速传能、传质及动量传递，均化温度场和熔质，起到细化晶粒、抑制成分偏析和松弛激光快凝过程的内应力，消除裂纹、气孔等缺陷的作用。在发明永磁式电磁搅拌装置的基础上，系统地研究激光沉积过程中缺陷的产生规律、金属熔体中磁场-电流-洛伦兹力之间作用机制及电磁场对熔池凝固的能量、动量和质量传递过程的影响规律；通过对电磁场下激光熔池凝固行为及微观组织演变的观察，进一步揭示电磁搅拌对激光熔池的凝固行为及其组织演化的影响机理，为精确控制激光沉积层组织和力学性能提供理论基础。

中文关键词： 钛合金；激光沉积制造；电磁搅拌；沉积层；旋转磁场

英文摘要： Laser Deposition Manufacture（LDM）is one of the most prospective means to fabricate and maintain the blisk and aero-engine casing of the next generation aero-engine key components. But it difficult to precisely control the quality and combination mechanical properties of components due to rapid heating and cooling rate of the LDM process.Rotating magnetic field can cause mixed convection according to the given motion law in the laser molten pool,which can enhance mass and energy transfer and make the temperature and solute distribution more uniform. So rotating magnetic field is introduced to the LDM of titanium alloy processes to refine the grain size, restrain composition segregation and reduce residual stress and defects.Based on the invented permanent magnet type electromagnetic stirring device, the magnetic -assisted LDM system was builded to fabricate the samples to study the the following key questions: forming mechanism of defects, mechanism of the magnetic field-current-lorentz force and its effects on metal melt mass and energy transfer, magnetic field mechanism acting on the solidification and microstructural evolution, which will be used as theoretical guide further to investigate the microstructural evolution law of LDM melten pool and reveal the magnetic field mechanism of action to provide the theo

英文关键词： Titanium Alloy；Laser Deposition Manufacture；Electromagnetic Stirring；Coating；Rotating Magnetic Field