This Grant Opportunities for Academic Liaison with Industry (GOALI) research project investigates an environmentally benign minimum quantity lubrication (MQL) technology, aiming to eliminate cooling system in production in order to enable cost-effective, energy efficient manufacturing, for drilling of the compacted graphite iron, a difficult-to-machine material in light-weight automotive powertrain applications. Drilling is the most common process in powertrain manufacturing but challenging with MQL due to tool wear and hole geometrical error caused by excessive heat and chip clogging. Specifically, this research will explore the feasibility of adding cooling capability to form the next-generation MQL to overcome this challenge. Cooling will be achieved by Joule-Thompson effect when high-pressure gas expands to the atmosphere at the cutting edge. Two gas sources, supercritical phase of carbon dioxide and compressed air, are selected for study because of their superior cooling capability. This research develops a drilling thermal model to quantitatively describe the cooling effects on the drill bit and workpiece, respectively, under a variety of conditions to allow predicting temperature distribution during drilling. Tool wear and workpiece distortion models will also be established based on the drilling thermal model. Upon selection of proper MQL conditions for drilling, a life cycle assessment will be performed to quantify the energy saving and sustainability of this new technology.
Research results will provide knowledge and understanding to develop the next-generation MQL for industry. Elimination of the flood cooling system can create significant savings in manufacturing operations. This research can also benefit industries where MQL is applicable. The GOALI project features a long-term and close collaboration between Ford Motor Company's Advanced Manufacturing Technology Development and University of Michigan, through which practical research with industry partnership and the technology implementation can be realized. It will also positively impact the engineering education by providing opportunities for students in the plant environment.
