Towards Sustainability Using Minimum Quantity Lubrication Technique and Nano-Cutting Fluids in Metal-Machining Processes

Abstract: Sustainable manufacturing is making products from processes which have minimal environmental impact, energy and resource efficient, economically viable and safe for consumers and society as whole. Achieving sustainability in manufacturing would mean infusing sustainability methods on product process and system level. On the process level, machining technology is one of the most widely extended processes in the industry. One way to attain sustainability in this technology is by adopting efficient management of Metal Working Fluids (MWF). In this purpose to reduce the amount of MWF starts Minimum Quantity Lubrication (MQL), where very small quantity of fluid is applied to the cutting zone with maximum precision. Moreover, addition of nanoparticles to these ´minimum quantity lubricants´ further enhances its tribological properties leading to higher reduction in friction and temperature in the machining process.The main objective of this thesis is to study the performance of cooling-lubricating fluids and these fluids modified with nanoparticles, how the use of this new lubricants improves the results obtained in material process technologies, particularly in turning. This project is being supported by the company LetsNano AB, providing the lubricants enhanced with nanoparticles and the funding, and Accu-Svenska AB, providing base oil and MQL technology.The experiments are carried out at Kungliga Tekniska Högskolan (KTH), at Institutionen för Industriell Produktion (IIP) laboratory. The turning process was tested with two different workipiece materials: hardened steel (Toolox® 44) provided by SSAB, and grey cast iron (Scania case study material). Two different tooling systems, due to the different materials. One provided by Mircona AB, and the other given directly by Scania, provided by Sandvik AB and Cermatec AB. The MQL system is a high-performance booster provided by Acuu-Svenska AB. The lubricant is a vegetable oil that will also be the base for the Nanofluids (NF). This Nanofluids and produced and developed by LetsNanoAB.The study revealed an encouraging potential of moving from conventional (dry) cooling techniques to the vegetable oil based MQL. Machining performance of MQL was encouraging as in most of the cases the systematic reduction in tool wear reveals a better machinability. The contribution of this work for Scania could help them to take the decision and move to more sustainable machining processes. To prove the potential of the nanotechnology in this kind of processes further study is needed, and it is going to be tested at IIP facilities in near future. The implementation of this technology brings more challenges that should considered a study of the hazards of the technology (emissions, fire and explosion, noise, skin…) necessary safety measures (cleaning, operator instruction, skin protection…) and modifications in the machine tools system beyond the process only. This could also be a next step in the further study of this research.