钛合金整体叶轮五轴侧铣切削力建模及过程阻尼效应下稳定性分析

The research background of this project is the NC flank milling with big axial cutting depth of aeroengine titanium alloy integral impellers. It aims at solving the stable, efficient and precision cutting problems of titanium alloy integral impellers. Process damping generated in the interface between the cutter flank and workpiece has an significant influence on cutting stability at low cutting speed caused by poor material cutting performance and complex part geometric features. In order to improve the accuracy of the stability prediction, the process damping is introduced into stability analysis in milling process.In this project, 5-axis flank milling force model of the impeller will be established from the kinematic point of view. The process damping will be indentified directly from chatter stability test. And then, the indentation coefficient of damping force is determined by energy balance. Based on the dynamic milling model considering both process damp and indentation coefficient comprehensively, the influence of process damp,indentation coefficient and process parameter on milling stability will be researched. Based on the above dynamic model, the maximum material removal rate optimization model will be founded with milling process stability and machining accuracy as constraints, and the high-performance parameters will be obtained by solving the model. Involving the common basic scientific problems of the aerospace field, this project will provide more accurate stability theory basis for milling titanium alloy.

项目以航空发动机钛合金整体叶轮大轴向切深侧铣数控加工为研究背景，旨在解决钛合金整体叶轮的稳定高效精密切削问题。刀具与工件接触区产生的过程阻尼对由材料切削性能差异及零件几何特征造成的低速切削稳定性具有重要影响。将过程阻尼效应引入到切削稳定性分析中，可以提高稳定域预报的精确性。项目从运动学角度建立叶轮侧铣加工五轴铣削力模型，从颤振实验角度识别过程阻尼，从能量守恒角度求解阻尼力的切入系数；基于综合考虑过程阻尼和阻尼力切入系数的动态铣削模型，研究过程阻尼、切入系数及工艺参数对铣削稳定性的影响；以上述动力学模型为基础，建立以铣削过程稳定性和加工精度为约束的最大材料去除率优化模型，并求解该模型以获取高性能工艺参数。项目涉及航空航天领域复杂曲面薄壁零件的共性应用基础科学问题，将为钛合金整体叶轮稳定高效精密铣削加工提供较为准确的理论依据。

为解决钛合金等难加工材料整体叶轮的稳定高效精密切削问题，提出基于过程阻尼效应下的稳定性分析的方法。本方法基于动力学和振动稳定性理论，通过切削实验与分析，揭示了过程阻尼效应与切削速度的关系，通过铣削力测定正交试验并运用极差值数表直观分析，对试验工艺参数进行优化提取，建立了基于过程阻尼的侧铣铣削动力学模型；利用锤击模态试验与有限元仿真模态参数提取法相结合，分析了工件在材料去除过程中模态参数的变化，获取了机床-刀具系统、工件-夹具系统的模态参数；以铣削动力学模型分析为基础，建立颤振稳定性边界曲线，获取无颤振高性能加工工艺参数，从而为航空发动机叶轮叶片铣削加工工艺优化提供完善的理论依据；提出了稳定性极限图工程化方法，指导了高效无颤振加工参数的选取，大大缩短了产品试制周期，提高了加工效率。上述研究成果为航空发动机叶轮叶片实际意义的高效加工提供了重要基础和有益借鉴，同时也为叶轮叶片类复杂型面零件加工企业的工艺决策提供了可靠的保障，因此，研究内容具有重要的现实意义与广阔的工程应用前景。