Collaborative Research: Full Field Measurement of Cutting Tool Surface Temperatures

本项目的目的是通过透明切削刀具测量在加工难加工合金过程中沿刀具-切屑界面和刀具-工件界面的温度分布。两种非接触式光学热成像技术，即红外热成像技术和双波激光诱导荧光技术，将用于刀具表面温度场的全场高分辨率测量。两种设计的透明切割工具将用于光学访问耙面和侧面。由温度敏感荧光粉制成的工具涂层将应用于透明工具上，以实现荧光热成像。一种新开发的分光镜将用于同时测量两个波长的红外强度。测量的空间分辨率将在1到10微米之间。采用双波激光诱导荧光，可以实现低至一微秒的时间分辨率。这些能力将代表着对当前技术状态的重大改进。高速、全场、表面温度测量的薄膜传感器的开发将用于各种需要非接触式温度监测的应用。这项研究将是荧光热成像技术第一次应用于研究切削温度，并将导致对新刀具和磨损刀具侧面温度的第一次直接观察。测量温度分布随工件厚度的变化将有助于提高我们对平面应力到平面应变转变的理解。测量的温度将有助于验证加工的有限元模拟，并导致改进材料本构模型，摩擦模型和刀具磨损模型。研究成果和方法将被纳入学术课程。将与威奇托州立大学的麦克奈尔学者项目建立伙伴关系，以吸引代表性不足的学生。

The objective of this project is to measure the temperature distributions along the tool-chip interface and along the tool-workpiece interface, through transparent cutting tools, during the machining of hard to machine alloys. Two non-contact optical thermography techniques, namely, infrared thermography and two-wave laser induced fluorescence, will be used for full-field, high resolution measurements of the temperature fields along the surfaces of cutting tools. Transparent cutting tools of two designs will be used to optically access the rake and flank faces. Tool coatings made of temperature sensitive phosphors will be applied over transparent tools to enable fluorescence thermography. A newly developed split-optic will be used to simultaneously measure the infrared intensity in two wavelengths. The spatial resolution of the measurements will be from one to ten micrometers. With two-wave laser induced fluorescence, temporal resolution as low as one microsecond can be achieved. These capabilities will represent a major improvement over the current state of the art.The development of thin film sensors for high speed, full field, surface temperature measurements will be of use in a variety of applications requiring non-contact temperature monitoring. This study will be the first application of fluorescence thermography to study cutting temperatures and will lead to the first direct observations of the flank face temperature of new and worn tools. Measurement of the variation of the temperature distribution through the thickness of the workpiece will help improve our understanding of the plane stress to plane strain transition. The measured temperatures will help validate finite element simulations of machining, and lead to improved material constitutive models, friction models and tool wear models. Research results and methods will be incorporated into academic courses. A partnership will be formed with the McNair scholars program at Wichita State University to attract underrepresented students.