Hybrid Nanofluid-MQL and Cold Air Cooling for Hard Milling: RSM–PSO Multi-response Optimization
Downloads
This study investigates a hybrid cooling–lubrication approach combining nanofluid-assisted minimum quantity lubrication (MQL) with cold-air cooling in the hard milling of SKD11 steel, aiming to improve both surface quality and productivity. Response surface methodology (RSM) was employed to model the relationships between machining parameters and two key performance indicators, namely surface roughness (Ra) and material removal rate (MRR). The developed models were integrated with particle swarm optimization (PSO) for multi-objective optimization. Compared with conventional MQL, the hybrid approach reduced Ra by approximately 5–10% under similar cutting conditions, indicating enhanced cooling and lubrication performance. The optimization results revealed distinct trade-offs between surface quality and productivity. When surface quality was prioritized (wRa = 0.7), a minimum Ra of 0.160 µm was achieved with a relatively low MRR of about 653 mm³/min. In contrast, both the balanced (wRa = 0.5) and productivity-oriented (wRa = 0.3) scenarios converged to the same optimal solution (Ra ≈ 0.245 µm, MRR ≈ 1790 mm³/min). This convergence suggests that MRR dominates the optimization when its weighting is comparable to or higher than that of Ra, indicating a plateau region on the trade-off surface. The proposed RSM–PSO framework provides both an effective optimization approach and new insight into balancing surface integrity and productivity in hybrid-cooled hard milling
Abd Rahim, E., & Dorairaju, H. (2018). Evaluation of mist flow characteristic and performance in minimum quantity lubrication (MQL) machining. Measurement, 123, 213–225. https://doi.org/10.1016/j.measurement.2018.03.015
Boswell, B., Islam, M. N., Davies, I. J., Ginting, Y. R., & Ong, A. K. (2017). A review identifying the effectiveness of minimum quantity lubrication (MQL) during conventional machining. International Journal of Advanced Manufacturing Technology, 92(1–4), 321–340. https://doi.org/10.1007/s00170-017-0142-3
Boubekri, N., & Shaikh, V. (2015). Minimum quantity lubrication (MQL) in machining: Benefits and drawbacks. Journal of Industrial and Intelligent Information, 3(3). https://doi.org/10.12720/JIII.3.3.205-209
Bui, G.-T., Nguyen, Q. M., Thi, M. H. P., & Vu, M. H. (2024). Multi-objective optimization for balancing surface roughness and material removal rate in milling hardened SKD11 alloy steel with SiO₂ nanofluid MQL. EUREKA: Physics and Engineering, 2, 157–169. https://doi.org/10.21303/2461-4262.2024.003042
Celent, L., Bajić, D., Jozić, S., & Mladineo, M. (2023). Hard milling process based on compressed cold air-cooling using vortex tube for sustainable and smart manufacturing. Machines, 11(2), 264. https://doi.org/10.3390/machines11020264
Chou, C.-C., Liu, N.-M., Chiang, K.-T., & Chang, H.-C. (2016). Investigation and optimization of Ti-6Al-4V titanium alloy in the fine grinding process using cold air gun coolant system. Hsiuping Journal, 33, 1–28. https://libap.nhu.edu.tw:8081/Ejournal/AI01003301.pdf
Davim, J. P. (Ed.). (2010). Surface integrity in machining. Springer. https://doi.org/10.1007/978-1-84882-874-2
Denkena, B., Köhler, J., & Bergmann, B. (2015). Development of cutting edge geometries for hard milling operations. CIRP Journal of Manufacturing Science and Technology, 8, 43–52. https://doi.org/10.1016/j.cirpj.2014.10.002
Dhar, N. R., Kamruzzaman, M., & Ahmed, M. (2006). Effect of minimum quantity lubrication (MQL) on tool wear and surface roughness in turning AISI-4340 steel. Journal of Materials Processing Technology, 172(2), 299–304. https://doi.org/10.1016/j.jmatprotec.2005.09.022
Do, T.-V. (2022). A case study of minimizing cutting force in hard milling JIS SKD61 steel under nanofluid-MQL condition. In Advances in engineering research and application: Proceedings of ICERA 2021, 12–18. Springer. https://doi.org/10.1007/978-3-030-92574-1_2
Do, T.-V., & Hsu, Q.-C. (2016). Optimization of minimum quantity lubricant conditions and cutting parameters in hard milling of AISI H13 steel. Applied Sciences, 6(3), 83. https://doi.org/10.3390/app6030083
Do, T.-V., & Le, N. A. V. (2025). Development of a multi-objective optimization model for the hard turning of SKD11 steel with nanofluid-Al₂O₃ minimum quantity lubrication using RSM and PSO. Engineering, Technology & Applied Science Research, 15(4), 24897–24903. https://doi.org/10.48084/etasr.11351
Do, T.-V., & Phan, T.-D. (2020). An empirical investigation of SiO₂ nano concentration under MQL on surface roughness in hard milling of JIS SKD61 steel. Journal of Applied Engineering Science, 18(3), 432–437. https://doi.org/10.5937/jaes18-27335
Do, T.-V., & Phan, T.-D. (2021). Multi-objective optimization of surface roughness and MRR in milling of hardened SKD11 steel under nanofluid MQL condition. International Journal of Mechanical Engineering and Robotics Research, 10, 357–362. https://doi.org/10.18178/ijmerr.10.7.357-362
Dong, L., et al. (2019). Analysis of the cooling performance of Ti–6Al–4V in minimum quantity lubricant milling with different nanoparticles. International Journal of Advanced Manufacturing Technology, 103(5–8), 2197–2206. https://doi.org/10.1007/s00170-019-03466-y
Dong, P. Q., Duc, T. M., Tuan, N. M., Long, T. T., Thanh, D. V., & Truong, N. V. (2020). Improvement in the hard milling of AISI D2 steel under the MQCL condition using emulsion-dispersed MoS₂ nanosheets. Lubricants, 8(6), 62. https://doi.org/10.3390/lubricants8060062
Ekici, E., & Uzun, G. (2022). Effects on machinability of cryogenic treatment applied to carbide tools in the milling of Ti-6Al-4V with optimization via the Taguchi method and grey relational analysis. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 44(7), 270. https://doi.org/10.1007/s40430-022-03572-1
Godson, L., Raja, B., Lal, D. M., & Wongwises, S. E. A. (2010). Enhancement of heat transfer using nanofluids—An overview. Renewable and Sustainable Energy Reviews, 14(2), 629–641. https://doi.org/10.1016/j.rser.2009.10.004
Gupta, M. K., Korkmaz, M. E., Sarıkaya, M., Krolczyk, G. M., & Günay, M. (2022). In-process detection of cutting forces and cutting temperature signals in cryogenic assisted turning of titanium alloys: An analytical approach and experimental study. Mechanical Systems and Signal Processing, 169, 108772. https://doi.org/10.1016/j.ymssp.2021.108772
Gupta, M. K., Korkmaz, M. E., Sarıkaya, M., Krolczyk, G. M., Günay, M., & Wojciechowski, S. (2022). Cutting forces and temperature measurements in cryogenic assisted turning of AA2024-T351 alloy: An experimentally validated simulation approach. Measurement, 188, 110594. https://doi.org/10.1016/j.measurement.2021.110594
He, T., Liu, N., Xia, H., Wu, L., Zhang, Y., Li, D., & Chen, Y. (2023). Progress and trend of minimum quantity lubrication (MQL): A comprehensive review. Journal of Cleaner Production, 386, 135809. https://doi.org/10.1016/j.jclepro.2022.135809
Hong, T. T., Vinh, D. T., Hung, T. V., Giang, T. N., Tu, N. T., Hung, L. X., ... & Tung, L. A. (2020, November). Multi-objective optimization of surface roughness and MRR in surface grinding of hardened SKD11 using grey-based Taguchi method. In International Conference on Engineering Research and Applications (pp. 584-593). Cham: Springer International Publishing. https://doi.org/10.1007/978-3-030-64719-3_64
Kadirgama, K. (2021). A comprehensive review on the application of nanofluids in the machining process. International Journal of Advanced Manufacturing Technology, 115(9–10), 2669–2681. https://doi.org/10.1007/s00170-021-07316-8
Korkut, I., & Donertas, M. A. (2007). The influence of feed rate and cutting speed on the cutting forces, surface roughness and tool–chip contact length during face milling. Materials & Design, 28(1), 308–312. https://doi.org/10.1016/j.matdes.2005.06.002
Kumar, Gaurav, Binayak Sen, Sudarsan Ghosh, and P. V. Rao. (2024). Strategic Enhancement of Machinability in Nickel-Based Superalloy Using Eco-Benign Hybrid Nano-MQL Approach. Journal of Manufacturing Processes, 127,457–476. https://doi.org/10.1016/j.jmapro.2024.08.015
Kumar, Mechiri Sandeep, and V. Murali Krishna. (2020). An Investigation on Turning AISI 1018 Steel with Hybrid Biodegradeable Nanofluid/MQL Incorporated with Combinations of CuO-Al2O3 Nanoparticles. Materials Today: Proceedings, 24, 1577–84. https://doi.org/10.1016/j.matpr.2020.04.478
Liu, Mingzheng, Changhe Li, Qinglong An, Yanbin Zhang, Min Yang, Xin Cui, Teng Gao, Yusuf Suleiman Dambatta, and Runze Li. (2025). Liquid Film Thickness Model Formed by Atomized Droplets during Sustainable Cryogenic Air MQL Grinding. Frontiers of Mechanical Engineering, 20(1), 8. doi:10.1007/s11465-025-0824-8.
Liu, Mingzheng, Changhe Li, Min Yang, Teng Gao, Xiaoming Wang, Xin Cui, Yanbin Zhang, Zafar Said, and Shubham Sharma. (2023). Mechanism and Enhanced Grindability of Cryogenic Air Combined with Biolubricant Grinding Titanium Alloy. Tribology International 187, 108704. https://doi.org/10.1016/j.triboint.2023.108704.
Liu, Mingzheng, Changhe Li, Yanbin Zhang, Qinglong An, Min Yang, Teng Gao, Cong Mao, et al. (2021). Cryogenic Minimum Quantity Lubrication Machining: From Mechanism to Application. Frontiers of Mechanical Engineering, 16(4), 649–97. doi:10.1007/s11465-021-0654-2.
Lotfi, Bahram, Ramazan Hakkı Namlu, and S. Engin Kılıç. (2024). Machining Performance and Sustainability Analysis of Al2 O3 -CuO Hybrid Nanofluid MQL Application for Milling of Ti-6Al-4V. Machining Science and Technology, 28(1), 29–73. doi:10.1080/10910344.2023.2287655.
Mac, T.-B., Luyen, T.-T., & Nguyen, D.-T. (2023). Assessment of the effect of thermal-assisted machining on the machinability of SKD11 alloy steel. Metals, 13(4), 699. https://doi.org/10.3390/met13040699
Namlu, Ramazan Hakkı, and Bilgin Kaftanoğlu. (2025). Enhancing Sustainable Machining of Inconel 718 Using Multi-Walled Carbon Nanotubes and TiO2 Based Nanofluid Minimum Quantity Lubrication. Procedia CIRP, 135,781–86. https://doi.org/10.1016/j.procir.2024.12.074.
Namlu, Ramazan Hakkı, Bahram Lotfi, and S. Engin Kılıç. (2024). Enhancing Machining Efficiency of Ti-6Al-4V through Multi-Axial Ultrasonic Vibration-Assisted Machining and Hybrid Nanofluid Minimum Quantity Lubrication. Journal of Manufacturing Processes, 119,348–71. https://doi.org/10.1016/j.jmapro.2024.03.073
Nguyen, H.-T., & Hsu, Q.-C. (2016). Surface roughness analysis in the hard milling of JIS SKD61 alloy steel. Applied Sciences, 6(6), 172. https://doi.org/10.3390/app6060172
Nipu, S. A., Karim, R., Rahman, A., Moon, M., Choudhury, I. A., Omar, J. B., & Khushbu, M. S. (2023). Turning SKD 11 Hardened Steel: An Experimental Study of Surface Roughness and Material Removal Rate Using Taguchi Method. Advances in Materials Science and Engineering, 2023(1), 6421918. https://doi.org/10.1155/2023/6421918
Özel, T., & Karpat, Y. (2005). Predictive modeling of surface roughness and tool wear in hard turning using regression and neural networks. International Journal of Machine Tools and Manufacture, 45(4–5), 467–479. https://doi.org/10.1016/j.ijmachtools.2004.09.007
Salur, Emin, Nursena Okcu, Mehmet Erdi Korkmaz, Kübra Kaya, Rüstem Binali, and Salih Bilal Çetinkal. (2025). Effect of Cooling/Lubrication Conditions on Machining Performance: An Experimental Investigation of 1040 Steel Under Dry, MQL, and Nano-MQL Environments. Materials, 18(17), 4063. https://doi.org/10.3390/ma18174063.
Sreejith, P. S., & Ngoi, B. K. A. (2000). Dry machining: Machining of the future. Journal of Materials Processing Technology, 101(1–3), 287–291. https://doi.org/10.1016/S0924-0136(00)00445-3
Stachurski, W., & Nadolny, K. (2018). Influence of the condition of the surface layer of a hob cutter sharpened using the MQL-CCA hybrid method of coolant provision on its operational wear. International Journal of Advanced Manufacturing Technology, 98(5–8), 2185–2200. https://doi.org/10.1007/s00170-018-2379-x
Vu, M. H., Hue, P. T. M., Huynh, N. T., & Nguyen, Q. M. (2024). Multi-objective Optimization for Enhanced Material Removal Rate and Reduced Machining Roughness in Hard Turning of SKD61 Alloy Steel. Mathematical Modelling of Engineering Problems, 11(3), 680–688. https://doi.org/10.18280/mmep.110312
Wang, Ziheng, Wei Yang, Zhenjing Duan, Shuaishuai Wang, Yuheng Li, Yuyang Zhou, Jiyu Liu, Jinlong Song, and Xin Liu. (2024). Experimental Study on Cold Plasma Jet (CPJ) Assisted Micro-Milling of 30CrMnSiNi2A. Intelligent and Sustainable Manufacturing, 1(2), 10017. https://doi.org/10.70322/ism.2024.10017
Weinert, K., Inasaki, I., Sutherland, J. W., & Wakabayashi, T. (2004). Dry machining and minimum quantity lubrication. CIRP Annals, 53(2), 511–537. https://doi.org/10.1016/S0007-8506(07)60027-4
Youssef, H. A., & El-Hofy, H. (2008). Machining technology: Machine tools and operations. CRC Press. https://doi.org/10.1201/9781420043402
Copyright (c) 2026 Journal of Engineering and Technological Sciences
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
