GOALI: Next-Generation Energy-Efficient Minimum Quantity Lubrication Deep Hole Drilling

该研究项目研究了一种环境友好的最小量润滑（MQL）技术，旨在消除生产中的冷却系统，以实现具有成本效益，能源效率的制造，用于压实石墨铁的钻孔，这是一种难以加工的材料，用于轻型汽车动力总成应用。 钻孔是动力总成制造中最常见的工艺，但由于刀具磨损和孔几何误差（由过热和切屑堵塞引起），MQL具有挑战性。具体而言，本研究将探索增加冷却能力以形成下一代MQL以克服这一挑战的可行性。当高压气体在切削刃口膨胀到大气中时，通过焦耳-汤普森效应实现冷却。两种气源，超临界相二氧化碳和压缩空气，被选为研究，因为他们的上级冷却能力。本研究发展一个钻削热模型，以定量描述在各种条件下，钻头和工件上的冷却效果，分别允许预测钻削过程中的温度分布。 在钻削热模型的基础上建立了刀具磨损和工件变形模型。在选择合适的MQL钻井条件后，将进行生命周期评估，以量化这项新技术的节能和可持续性。研究结果将为开发下一代MQL提供知识和理解。消除溢流冷却系统可以在制造操作中产生显著的节省。 这项研究也可以使MQL适用的行业受益。GOALI项目的特点是福特汽车公司先进制造技术开发部与密歇根大学之间的长期密切合作，通过这种合作，可以实现与工业伙伴关系的实际研究和技术实施。 它还将通过为学生提供在工厂环境中学习的机会，对工程教育产生积极影响。

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.