This collaborative research award supports fundamental research on rotary ultrasonic machining of titanium and its alloys in order to develop an innovative and cost-effective titanium drilling process for the nation's aerospace industry. Specifically, the research will develop a physics-based predictive model for cutting forces in drilling titanium with rotary ultrasonic machining and conduct experiments to verify the model, test the hypothesis that coolant-flow direction is the determining factor for surface roughness in titanium rotary ultrasonic machining, evaluate the feasibility of using cold air as a coolant to replace cutting fluids in titanium rotary ultrasonic machining, establish the relationship between the dominating tool-wear mechanism and machining conditions, measure the cutting temperatures, and quantify the damage to machined titanium parts caused by rotary ultrasonic machining and twist drilling.
Research results will provide knowledge and understanding to meet the critical need to develop more cost-effective titanium drilling processes for the nation's aerospace industry. A globally competitive aerospace industry will contribute to the nation's economy, and airplanes with better quality and lower manufacturing cost will benefit consumers and the society. Research results will also benefit other industries where titanium is widely used. By replacing cutting fluids with cold air as a coolant, the research will have a positive impact on the environment. This collaborative research project features a unique collaboration among Kansas State University, University of Massachusetts Lowell, Argonne National Laboratory, and industry. This collaboration provides excellent synergy for project resources, ensures the relevance of the research to industry, and expedites technology commercialization. It will also positively impact engineering education at two universities, promote lifelong learning for industrial practitioners, and broaden participation of underrepresented groups in research.
(NSF: CMMI-0856204; $27,115; 07/09-06/13)" Project Summary The objective of the Collaborative Research - Fundamental Research on Titanium Drilling with Rotary Ultrasonic Machining, is to better understand the knowledge about temperature distribution during rotary ultrasonic machining (RUM) of titanium (Ti) in order to develop an innovative and cost-effective Ti drilling process for the U.S. aerospace industry. Titanium has a wide variety of applications, particularly in the aerospace industry. However, because of its low thermal conductivity and high strength, machining of titanium is very difficult. The heat generated in machining can dramatically shorten the tool life. Rotary ultrasonic machining (RUM) is a nontraditional machining process, and has been used to machine various difficult-to-machine materials. Investigations have been reported regarding effects of machining variables (including ultrasonic power, tool rotation speed, and feedrate) on several output variables in RUM, such as cutting force, torque, surface roughness, edge chipping, material removal rate, and tool wear. However, there have been few studies on cutting temperatures in RUM. This project is the first research study to utilize fiber optic temperature sensors to monitor the cutting temperature in RUM. Fiber optic temperature sensors (FOTS) offer unique advantages when used to measure cutting temperature in RUM machining processes. The FOTS is immunized to the electromagnetic interference, and could achieve higher spatial resolution than conventional temperature measurement methods such as thermocouples. During this research project, the fiber optic temperature sensors were designed, fabricated, calibrated and finally used for the RUM system. During RUM, the sensor is embedded in the titanium workpiece to monitor the temperature change based on three machining variables (ultrasonic power, tool rotation speed, and feedrate). The results are consistent with the assertion that FOTS provide more accurate localized measurement in RUM than thermocouples. Furthermore, experimentally obtained results can provide foundations for attempts to develop simulation models to predict cutting temperatures at the tool-workpiece interface. One Ph.D student, one master student, and one REU student has been supported and worked on this project. Three journal papers, one conference paper, and two research posters have been published based on this research topic. The Ph.D student worked on this project has been awarded with Student Fellowship for the both 2011 and 2012 NSF-CMMI Research and Innovation Conference. Students Supported Ph.D. student: Xiaotian Zou, Master student: Charles Guthy, REU student: Vinicius Silva Journal publication [1] Xiaotian Zou, Weilong Cong, Nan Wu, Ye Tian, Z.J. Pei, and Xingwei Wang, "Cutting temperature in rotary ultrasonic machining of titanium: Experimental study using novel Fabry-Perot fiber optic sensors", International Journal of Manufacturing Research, 8(3), 250-261, 2013. [2] Charles Guthy, Xiaotian Zou, Zhijian Pei, and Xingwei Wang , "A review of temperature measurement methods for twist drilling processes", International Journal of Machining and Machinability of Materials, 13(4), 372-397, 2013. [3] Weilong Cong, Xiaotian Zou, T.W. Deines, Nan Wu, Xingwei Wang, and Z.J. Pei, "Rotary ultrasonic machining of CFRP composites: an experimental study on cutting temperature", Journal of Reinforced Plastics and Composites, 31(22), 1516-1525, 2012 Conference publication [1] Xiaotian Zou, Weilong Cong, Nan Wu, Zhijian Pei, and Xingwei Wang, ''Novel fiber optic sensors and their application on cutting temperature measurement in rotary ultrasonic machining of titanium'', Accepted by ASME International Symposium on Flexible Automation (ISFA2012). [2] Xiaotian Zou, Weilong Congi, Z.J. Pei, and Xingwei Wang, ''Collaborative Research: Fundamental Research on Titanium Drilling with Rotary Ultrasonic Machining'', NSF CMMI Engineering Research and Innovation Conference, Boston, July 9-12, 2012. [3] Xiaotian Zou, Charles Guthy, Weilong Cong, Zhijian Pei and Xingwei Wang, "Cutting temperature distribution in rotary ultrasonic machining of titanium alloy: Finite element analysis and experimental design using an optical temperature sensor array", CMMI Research and Innovation Conference, Atlanta, Georgia, January 4-7, 2011 Student Awards: Xiaotian Zou, outstanding graduate student award, ECE dept., UMass Lowell. Graduate Student Fellowship for the NSF CMMI Engineering Research and Innovation Conference, 2012. Graduate Student Fellowship for the NSF CMMI Engineering Research and Innovation Conference, 2011.
