基于机床功率的多轴加工刀具寿命评价及表面完整性预测与控制

For machining complex components of aero-engine, in this process there are many issues such as complicated working conditions, serious time-variation, violent changes in cutting load, and severe tool wear degradation appeared, which lead to the uneven machined surface state, and while the possible potential fatigue sources on the machined surface are disadvantage to the service life and reliability of the aero-engine. The existing methods to control surface integrity mostly have not adequately considered the complexity of tool wear degrading process, and the research on its evolutional law and influence mechanism is still insufficient. In this project, taken the complex components of aero-engine as the research object, to investigate and explore the tool life evaluation method on machining complex structure based on machine power and the process control method of machining surface integrity considering tool wear degradation, and establish a prediction model of machine power for component geometric feature machining, in order to achieve the accurate prediction of machine power considering the cutting tool time-variant state during the multi-axis machining process. And on this basis, based on the correlation model of power signal-geometric characteristics-process parameters, to achieve a more accurate prediction of the cutting tool remaining useful life by integrate the multiple characteristics of operating condition. This project will propose the correlation model of tool wear, machine power and surface integrity, and reveal the formation mechanism and evolution law of surface integrity influenced by the time-variant state of cutting tool, and to master the process parameter optimization and control method of surface integrity considering the influence of time-dependent of tool wear. The research results will provide the basic theory and technological method for ensuring the long life and high reliability manufacturing of complex components of aero-engine for our country.

航空发动机复杂构件加工过程工况复杂、时变性强、切削载荷变化剧烈、刀具磨损退化严重，导致加工表面状态分布不均，可能存在潜在的疲劳源，对发动机寿命和可靠性造成极大的影响。现有表面完整性控制方法未考虑刀具磨损退化过程的复杂性，对其演化规律和影响机理研究尚显不足。本项目以发动机复杂构件为对象，开展基于机床功率的复杂构件加工刀具寿命评价与考虑刀具磨损退化的加工表面完整性工艺调控方法研究，建立面向构件几何特征加工的机床功率预测模型，实现多轴加工时考虑刀具时变状态的机床功率精确预测；在此基础上，基于功率信号-几何特征-工艺参数关联模型，实现融合工况特征的刀具剩余寿命精确预测；建立刀具磨损量-机床功率-表面完整性的关联模型，揭示刀具时变状态的加工表面完整性形成机理与演化规律，掌握基于刀具时变状态的加工表面完整性工艺参数优化调控方法，为保障我国航空发动机复杂构件的长寿命高可靠制造提供基础理论与工艺方法。

航空发动机复杂构件加工是国产发动机研制过程中的关键与难点，在实际加工过程中因工况复杂多变、切削载荷变化剧烈等导致的刀具磨损退化严重、零件表面质量一致性差等问题，亟需大量理论探索与试验研究的支撑解决。在此背景下，本项目以航空发动机复杂构件加工为研究对象，开展了理论与试验研究，取得了一定的研究成果。首先，建立了面向复杂加工过程的加工各向异性机床功率预测模型，为低能耗制造过程的加工参数优化与加工路径优化奠定了理论基础；其次，得到了刀具磨损退化过程对切削功率的影响规律，阐明了切削功率和刀具磨损的关联关系，提出了基于功率信号的跨工况条件刀具磨损监测与预测方法，该方法的提出为实际生产过程中，复杂工况条件下的维护和管理刀具状态提供了一定的技术支持；同时，研究了加工过程中不同刀具姿态刀具磨损规律与退化机制，获得了刀具磨损状态下的铣削力与铣削问题变化规律，阐明了刀具时变状态对高温合金表层状态的影响规律；分析了加工表面残余材料高度的结构特征与分布规律，提出了基于概率学算法的加工表面三维形貌表征和粗糙度参数预测模型，掌握了基于时变工况下的难加工材料加工表面完整性工艺控制方法。本研究所取得的相关理论与试验研究成果将为航空发动机难加工材料复杂构件的长寿命高可靠制造工艺方法提供基础理论与数据支撑。