激光沉积熔池形貌演化机理及成形精度控制研究

项目名称： 激光沉积熔池形貌演化机理及成形精度控制研究

项目编号： No.51505301

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 机械、仪表工业

项目作者： 钦兰云

作者单位： 沈阳航空航天大学

项目金额： 20万元

中文摘要： 钛合金激光沉积制造技术在航空航天等领域具有广阔的应用前景，但其较低的制造效率和制件尺寸精度成为限制其发展的主要因素。本项目针对激光沉积制造过程不均匀的热分布导致成形制件几何性能低的问题，选用TA15近alpha相钛合金为研究对象，运用理论分析、数值模拟和试验相结合的方法，通过研究制造过程中的温度场分布及热循环特性，揭示不同工艺参数下激光熔池凝固及相变过程的热传递特性；研究热累积对激光熔池形貌尺寸演变影响规律，结合试验数据和数值模拟结果提出熔池尺寸控制方法；建立温度场、热力耦合场数值模型，研究制造过程中应力演化规律及制件的变形行为；综合考虑热行为、变形及熔池尺寸，建立制件尺寸预测模型和设计实时控制算法，通过工艺试验修正和完善预报模型，实现激光沉积制造过程的主动控制，为提高成形件的效率和质量提供理论依据和方法指导。

中文关键词： 激光沉积制造；钛合金；成形精度；热行为；熔池

英文摘要： Titanium alloys laser deposition manufacturing technology is widely used in aerospace and some other fields, but its low efficiency and dimension accuracy are the main factors to limit its development.The near alpha-Ti alloy represented by TA15 alloy is prepared for the investigation of the low geometrical characteristic due to uneven thermal distribution,Then the following key questions in the project will be studied systematically: distribution of temperature field and thermal cycle characteristics, which are helped to reveal heat transfer characteristics for the solidification and phase transformation by the method of combining theoretical model, simulation with experiments.The project also aims to reveal the law on effect of thermal accumulation on laser melt pool shape evolution and propose a method of controlling the pool dimensions based on the experimental and numerical data. Then a multi-field coupling model of temperature field and stress field is build to study parts stress evolution and distortion behavior.At last, thermal behavior, distortion and laser melt pool dimensions are taken into account to build a dimension prediction model and design a real-time control algorithm, then the model is validated by experiments to implement LDM active control to provide the theoretical basis and method guidance for improving the quality of deposited components.

英文关键词： Laser deposition manufacturing;Titanium alloy;Forming accuracy;Thermal behavior;Melt pool