嵌入薄膜热电偶的智能切削测温刀具关键问题研究

Smart cutting tool, as a research hotspot in the field of modern machinery manufacturing, is receiving growing popularity and focus. This project targets at the technical problem of monitoring transient cutting temperature in high-speed precision cutting process and focuses on solving the core problem of temperature-measuring smart cutting tool with embedded thin film thermocouple. The research consists of: 1) Adopting specialized polishing mold, magnetron sputtering film preparation and target、mask control technology to investigate the design and manufacturing methods of embedding thin film thermocouple into tips of cutting tools. 2) Formulating the method and constructing the system of static and dynamic calibration of of temperature-measuring smart cutting tool.3) Introducing Boltzmann statistics and Fermi-Dirac function to solve theoretical problems regarding technical characteristics of temperature-measuring smart cutting tool. 4) Constructing an intelligent cutting temperature monitoring system which includes a terminal data acquisition system integrated into arbor of the cutting tool, coordination system, database and PC software. 5) Exploring effective ways of exporting data from the temperature-measuring smart cutting tool and communicating with open CNC machine control unit. The temperature-measuring smart cutting tool developed will have integrated functions of both cutting and temperature measurement thus will be able to perform precise and real time measurement of transient temperature of the cutting area at the production site. Achievement of this project will establish a solid foundation of cutting tool status monitoring technology and offer theoretical support to the development of cutting database and the improvement of CNC machining efficiency.

智能切削刀具是现代机械制造领域的发展和研究热点之一。本项目针对高速精密切削过程中瞬态切削温度监控的技术难题，重点解决嵌入薄膜热电偶智能切削测温刀具的关键问题。主要研究内容包括：1)采用专用抛光模具、磁控溅射薄膜制备工艺和靶材、掩膜控制技术，研究将薄膜热电偶直接嵌入切削刀具刀尖的设计与制造方法；2）研究智能测温刀具的静态和动态性能自动标定方法与系统；3）引入玻尔兹曼经典统计和费密狄拉克函数，研究智能测温刀具技术特性相关理论问题；4）研制包括可集成于刀杆的终端数据采集系统、协调器系统、数据库和上位机软件的智能切削温度监控系统。5）探索智能测温刀具输出数据与开放式数控机床控制单元通信的有效途径。研制的智能切削测温刀具集切削、测温功能于一体，能够在生产现场对切削区域瞬态温度进行准确和实时测量。项目研究成果可为切削刀具状态监测技术发展奠定基础，为我国切削数据库的建设和数控加工效率的提高提供理论支持。

智能切削刀具是现代机械制造领域的发展和研究热点之一。本项目针对高速精密切削过程中瞬态切削温度监控的技术难题，开展了嵌入薄膜热电偶智能切削测温刀具关键问题的研究。主要包括：1)依据切削刀具材料与结构特点，通过专用抛光模具、靶材与掩模控制，研究了将薄膜热电偶直接嵌入切削刀具刀尖的设计与制造方法；完成了利用磁控溅射技术在刀具后刀面制备包括SiO2绝缘薄膜、NiCr/NiSi热电极薄膜和SiO2保护薄膜的磁控溅射制备工艺研究。2)完成了嵌入切削刀具的多层薄膜的性能及界面结构的表征，薄膜元素成分分布准确，薄膜截面接触良好、薄膜厚度均匀且截面平整；NiCr/NiSi薄膜截面接触处元素相互轻微渗透，两种热电极薄膜结合良好。3)研究了智能切削测温刀具的静态和动态性能自动标定方法，建立了包括温度干式计量炉、冰点器、高精度数据采集卡、精密放大电路和基于C#语言开发的计算机软件的薄膜热电偶自动标定系统。4)完成了智能切削测温刀具静、动态性能的标定，研究了智能切削测温刀具塞贝克系数与动态响应时间的变化规律，NiCr /NiSi薄膜热电偶测温刀片的塞贝克系数（灵敏度）S为40.5μV/℃，线性拟合误差小于0.92%，在测温范围内最大误差仅为±0.25℃，薄膜热电偶动态响应时间为0.132ms；薄膜热电偶热接点跟随刀具后刀面的磨损对其静态、动态性能无影响。5)研制了包括可集成于刀杆的终端数据采集系统、协调器系统、数据库和上位机软件的智能切削温度监控系统。6)完成了嵌入薄膜热电偶的智能切削测温刀具的实验验证。结果显示，采用研制的瞬态切削用智能测温刀具可以监测0.1s内刀具刀尖切削区域瞬态切削温度变化，智能切削测温刀具集切削、测温功能于一体，能够在生产现场对切削区域瞬态温度进行准确和实时测量。项目研究成果可为切削刀具状态监测技术发展奠定基础，为我国切削数据库的建设和数控加工效率的提高提供理论支持。