The research objective of this award is to measure the temperature at the tool/workpiece interface during precision machining for depths of cut less than 10 micrometers to an accuracy of 5 degrees Celsius. To make this measurement, a number of important sensors will be added to a precision lathe that already has 3-dimensional force sensors. Visual and infrared microscope systems will be added to view the material flow in the chip at small depths of cut. These will provide an overall view of the temperature distribution in relation to the chip/tool interface. In addition, a unique elliptically shaped, light-guiding diamond tool will be fabricated to focus the infrared radiation from the tool tip into a spectrometer and improve the sensitivity of the peak tool temperature measurement. A unique wear measurement technique will be used to compare the tool wear with changes in material, depth of cut, temperature and cutting distance.
Keeping the tool edge sharp and avoiding degradation with time are key factors in machining materials like steel where chemical wear due to temperature dominates. Models of the machining process are available to calculate tool temperature, but measurements are needed to corroborate these results. If successful, the benefits and impact of this research will be improved knowledge of precision manufacturing processes and education of scientists and engineers. The proposed temperature measurement is needed to 1) corroborate models of the machining process and 2) predict tool wear when machining important structural materials like steel. Optical and precision mechanical systems play a pervasive role in modern life in the US and require nanometer-scale fabrication processes to yield the required performance. There is a critical need to improve these manufacturing processes, to visualize new processes and to educate the next generation of students needed to create them. The technical results will be published in engineering journals and integrated into university courses. The graduate and undergraduate students involved will develop expertise in key areas like machine design, control, materials response, dynamic systems and precision manufacturing.
