基于I-kaz方法的高温合金高效铣削刀具热磨损规律研究

This proposal investigates the mapping between tool wear and milling thermal in high efficiency milling of high-temperature alloy, and proposes a new method for prediction of tool wear. Based on the signal processing I-kaz method, it explores the diffusion of milling heat on tool coating, and thus the influence of tool wear. The multiple factors involved in tool wear issue were changed into the optimal control of milling temperature of this single factor, and a macro-control model with the direct characterization of the milling temperature on tool wear prediction was established. According to this model, it proposed the assumption that the heat source distribution in tool / workpiece contact arc area is the isosceles trapezoid, accordingly constructed the milling temperature calculation model, and based on Maxwell -Eucken 1, Series, and Equivalent layer structure models, it considered the effective thermal conductivity of the diffusion layer of coated tools, and built a mapping model between the milling temperature signals and tool wear using the I-kaz method, which was used to achieve tool wear real-time online monitoring, and ultimately formed a complete set of theory, craft programs and simulation software for the early warning of tool wear or failure in milling of high-temperature alloy parts. The proposal was designed to break through the technical bottleneck in high efficiency milling of high-temperature alloy parts, and guide the coated tool design and selection, forming the core technology with independent property rights.

本项目研究高温合金高效铣削中刀具磨损和铣削热之间的映射关系，提出一种刀具磨损预测新方法。基于信号处理I-kaz方法，探索铣削热对刀具涂层扩散，进而对刀具磨损的影响规律。将刀具磨损的多因素影响问题转化为对单因素铣削温度的优化控制，建立直接表征铣削温度对刀具磨损预测的宏观控制模型。在此模型基础上，提出刀具/工件接触弧区热源为等腰梯形分布的假设，据此构造铣削温度计算模型，并在基于Maxwell-Eucken 1、Series、以及Equivalent layer等结构模型上，考虑涂层刀具扩散层的有效热传导问题，建立基于I-kaz 方法的铣削温度信号与刀具磨损量之间的映射模型，实现对刀具磨损的实时在线监测，最终形成一套完整的面向高温合金零件加工刀具磨损或失效的早期预警理论方法、工艺方案和仿真软件，旨在突破高温合金高效铣削加工中的技术瓶颈，指导涂层刀具的设计与选型，形成具有自主产权的核心技术。

高温合金以其高强度、强抗腐蚀能力以及优异的热疲劳特性和热稳定性在航空发动机压气机盘、涡轮盘、承力环、机匣、叶片等高温下长期工作的发动机零部件有着广泛的应用。但这类零件铣削加工非常困难，直接导致加工效率低下。分析原因，频繁刀具磨损是影响加工效率最直接的因素，而由高温合金加工硬化所引起的铣削温度急剧升高又是加快刀具磨损的关键因素。本项目紧密围绕高温合金高速铣削加工中显著的切削热和刀具磨损现象，开展了如下研究工作：（1）提出了刀具-工件接触弧区热源为等腰梯形分布的假设，据此构造了铣削工件表面温度计算模型。研究工作为合理优化工艺参数来提高工件表面温度预测精度以及后续涂层刀具温度模型优化提供了理论指导；（2）建立了充分考虑后刀面磨损影响的涂层刀具热传导物理模型来估算刀具温度分布，并结合实验、解析计算和数值分析等方法，确定了刀-屑对流热交换系数。该系数可作为仿真模型的输入，实现对刀具温度变化的精确仿真；（3）提出了一种基于工件硬化层影响的刀具磨损预测新模型，用于阐述陶瓷刀具沟槽磨损和工件表面微观硬度形貌之间的关系。研究发现，存在一个临界的硬化层引起沟槽磨损，且持续增加的硬化层引起沟槽磨损深度急剧增加，并最终导致刀具失效；（4）利用I-kaz方法，开发了基于铣削温度信号的刀具磨损在线监测软件，为高温合金高速铣削加工中刀具磨损的主动控制提供了一种新思路。以上取得的理论研究成果和关键技术成果应用于高温合金复杂叶片多轴铣削加工，指导实际生产，有效发挥了企业机床设备的最大功效。