Sustainability-based performance evaluation of hybrid nanofluid assisted machining Aqib Mashood Khan a , Muhammad Jamil a, * , Mozammel Mia b , Ning He a, ** , Wei Zhao a , Le Gong a a College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China b Department of Mechanical Engineering, Imperial College London, South Kensington, SW7 2AZ, London, United Kingdom article info Article history: Received 9 January 2019 Received in revised form 28 January 2020 Accepted 10 February 2020 Available online xxx Handling Editor: CT Lee Keywords: Sustainable manufacturing Energy consumption Alumina-graphene Hybrid nanofluid Cumulative energy demand Carbon emission abstract China’s industrial sector accounts for more than half of the country’s total energy demand. During 2010 e2012, nearly 73% of the total hike in the global carbon emission has occurred in China alone. According to the regulations of the International Organization for Standardization, the material processing industry is required to cut down the energy consumption demand and carbon emission. It is worthwhile to consider the elimination of cutting fluids from the machining domain for reducing production cost and environmental impact. This study presents component-stage based holistic models of energy, cost, and carbon emission. The models are validated through the experimental data obtained from turning of Haynes 25 alloy conducted under nanofluid (alumina-graphene) assisted minimum quantity lubrication. The data for energy consumption, cost, and CO 2 emission are obtained from the experimental work and literature. The results show that the feed rate possesses the most significant effect on energy con- sumption. The shares of the work material’s choice in total energy consumption, carbon emission, and total cost are found to be 93.7%, 66.8%, and 56.2%. The nanoparticles share a small portion of the total cost per unit product. The Environmental Performance Index (EPI) obtained in this study reveals a strong possibility of the industrial application of nanofluids in machining. This study also preaches “think green, plan green, and go green.” © 2020 Published by Elsevier Ltd. 1. Introduction A rapid increase in energy prices, economical production, low carbon manufacturing, and environmental upshots such as climate change are forcing the metal processing industry to seek new so- lutions for sustainable manufacturing. High energy consumption during manufacturing means more cost e both economic and environmental costs. In machining, the cost per part becomes higher due to the potent challenges faced during the material removal stages. This problem becomes blatant in the case of pro- ducing parts using cobalt-based high-temperature alloy, such as Haynes 25. The utilization of cutting tool and power consumption in machining are influenced by the selection of coolants, lubricants, and mechanism of coolant/lubricant application. The application of conventional emulsions accounts for 7.5e17% of the total machining cost and causes severe environmental issues during their application in machining (Khan et al., 2019). In machining difficult-to-cut materials, the cost of coolant acquisition, prepara- tion, use, and disposal is four times higher (Devillez et al., 2011). To address these issues, Minimum Quantity Lubrication (MQL) uses a minimal amount of lubricant and removes post-cleaning and disposal related activities. The performance of the MQL system can be enhanced by using hybrid nanofluids. Sustainability-based per- formance evaluation of hybrid nanofluid MQL assisted machining from 3E (Energy, Environment, and Economy) perspective is inevitable. In 2014, the industrial sector consumed 42.5% of the world’s total electrical energy consumption, a three-times increase since 1973 engrossing 8432 TWh energy (IEA, 2016). China surpassed the United States in 2009, became the largest energy-consuming country. It is expected that China’s energy consumption will continue to increase due to the development of new industrial * Corresponding author. ** Corresponding author. E-mail addresses: engr.jmail@nuaa.edu.cn (M. Jamil), m.mia19@imperial.ac.uk (M. Mia), drnhe@nuaa.edu.cn (N. He). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro https://doi.org/10.1016/j.jclepro.2020.120541 0959-6526/© 2020 Published by Elsevier Ltd. Journal of Cleaner Production 257 (2020) 120541