مطالعه تجربی تأثیر خنک‌کننده گازی در فرزکاری پلی‌تترافلئورواتیلن بر خصوصیات سطح

نوع مقاله : مقاله پژوهشی (کاربردی)

نویسندگان

1 عضو هیئت علمی، گروه مهندسی مکانیک، دانشگاه فنی و حرفه‌ای، تهران، ایران.

2 دانشیار، گروه شیمی آلی و بیوشیمی، دانشکده شیمی، دانشگاه تبریز، تبریز، ایران.

چکیده

دستیابی به صافی سطح مطلوب با ساختاری کارا در ماشین‌کاری پلی‌تترافلوئوراتیلن (PTFE) به دلیل رفتار ویسکوالاستیک آن، معضلی اساسی است. هدف این پژوهش بررسی تأثیر به‌کارگیری خنک‌کننده‌های گازی و فاکتورهای ماشین‌کاری بر صافی و ساختار سطوح قطعات از این جنس است. برای این منظور اثر دمش گاز نجیب آرگون و گاز فعال دی­اکسیدکربن با طرح سرعت برشی و پیشروی به‌عنوان متغیرهای مستقل در ماشین‌کاری PTFE ارزیابی گردید. صافی سطوح توسط معیار Ra اندازه­گیری شد. ساختار میکروسکوپی سطوح نیز توسط میکروسکوپ­های نوری و روبشی الکترونی بررسی گردید. برای اندازه­گیری دمای ماشین‌کاری، عملیات توسط دوربین حرارتی با دقت بالا فیلم‌برداری گردید. نتایج نشان می‌دهد که استفاده از گاز دی‌اکسیدکربن می‌تواند با کاهش دمای موضع ماشین‌کاری تا C40°-، رفتار برشی ماده را از ویسکوالاستیک به الاستوپلاستیک تغییر دهد و زبری سطح را تا Ra=0.2 µm پایین آورد. مطالعات میکروسکوپی نشان داد گاز دی‌اکسیدکربن می‌تواند رفتار ویسکوز در حین برش را که موجب سیلان ماده می­شود، کنترل و از پیدایش ترک­های سطحی جلوگیری کند و همچنین سطح را از تشکیل گروه­های عاملی و تغییرات شیمیایی حین ماشین‌کاری محافظت کند. در بررسی­های میکروسکوپی معلوم شد که استفاده از گاز دی‌اکسیدکربن از چسبیدن مجدد براده­های جدا شده به سطح جلوگیری می­کند. 

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Study of the Gaseous Coolants Influence in the Milling of Polytetrafluoroethylene on the Surface Characteristics

نویسندگان [English]

  • Ayub Karimzad Ghavidel 1
  • Gholamreza Kiani 2
1 Faculty Member, Department of Mechanical Engineering, Technical and Vocational University (TVU), Tehran, Iran.
2 Associate Professor, Department of Organic Chemistry and Biochemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
چکیده [English]

The achievement of a desirable surface roughness with an efficient structure is a major challenge in machining of Polytetrafluoroethylene (PTFE) owing to its viscoelastic behavior. The aim of this research is to investigate the effect of gaseous coolants utilization on the roughness and structure of surfaces.  For this purpose, the effect of Argon noble and CO2 effective gases on the machining of PTFE were evaluated, taking into consideration the cutting and feed velocities as input factors. The surface roughness was measured by Ra criterion.  The microscopic structure of surfaces was investigated using optical and scanning electron microscopes. To measure the machining temperature, the operation was recorded by high accurate thermal camera. The results show that the utilization of CO2 due to decreasing local machining temperature to below -40°C can change the cutting behavior of material from viscoelastic to elastoplastic, and reduces the surface roughness up to Ra=0.2 µm. Microscopic studies indicate that the using of CO2 can govern the viscous behavior during cutting which causes the viscous-flowing of material and prevents the generation of surface cracks. CO2 also protects the surface from chemical interactions and creation of functional groups during the machining. Microscopic examination revealed that the use of carbon dioxide gas prevents separated chips from re-adhering to the surface.

کلیدواژه‌ها [English]

  • PTFE machining
  • Gaseous coolant
  • Surface roughness
  • Morphology
  • Decreasing of elastoplastic effect
[1] Dhanumalayan, E., & Joshi, G. M. (2018). Performance properties and applications of polytetrafluoroethylene (PTFE)—a review. Advanced Composites and Hybrid Materials, 1(2), 247-268. https://doi.org/10.1007/s42114-018-0023-8
[2]Dupont. (2021). Teflon PTFE fluoropolymer resin. Rjchase. http://www.rjchase.com/ ptfe_handbook.pdf
[3] Bijwe, J., & Sharma, M. (2012). Nano and Micro PTFE for Surface Lubrication of Carbon Fabric Reinforced Polyethersulphone Composites. In Tribology of Nanocomposites (19-39) .Springer. https://doi.org/10.1007/978-3-642-33882-3_2
[4] Feng, Y., Xiong, T., Jiang, S., Liu, S., & Hou, H. (2016). Mechanical properties and chemical resistance of electrospun polyterafluoroethylene fibres. RSC advances, 6(29), 24250-24256. https //:doi.org/doi.org/10.1039/C5RA27676D
[5] Khedkar, J., Negulescu, I., & Meletis, E. I. (2002). Sliding wear behavior of PTFE composites. Wear, 252(5), 361-369. https://doi.org/10.1016/S0043-1648(01)00859-6
[6] Li, J., & Ran, Y. (2010). Evaluation of the friction and wear properties of PTFE composites filled with glass and carbon fiber. Materialwissenschaft und Werkstofftechnik, 41(2), 115-118. https://doi.org/10.1002/mawe.200900545
[7] Khoddamzadeh, A., Liu, R., & Wu, X. (2009). Novel polytetrafluoroethylene (PTFE) composites with newly developed Tribaloy alloy additive for sliding bearings. Wear, 266(7), 646-657. https://doi.org/10.1016/j.wear.2008.08.007
[8] Cheng, X., Xue, Y., & Xie, C. (2003). Tribological investigation of PTFE composite filled with lead and rare earths-modified glass fiber. Materials Letters, 57(16), 2553-2557. https://doi.org/10.1016/S0167-577X(02)01310-1
[9] Unal, H., Kurtulus, E., Mimaroglu, A., & Aydin, M. (2010). Tribological Performance of PTFE Bronze Filled Composites under Wide Range of Application Conditions. Journal of Reinforced Plastics and Composites, 29(14), 2184-2191. https://doi.org/10.1177/0731684409345617
[10] Younse, P., Alwis, T. d., Backes, P., & Trebi-Ollennu, A. (2012, March 3-10 ). Sample sealing approaches for Mars Sample Return caching. 2012 IEEE Aerospace Conference, Big Sky, MT, USA https://ieeexplore.ieee.org/abstract/document/6187048
[11] Fetecau, C., & Stan, F. (2012). Study of cutting force and surface roughness in the turning of polytetrafluoroethylene composites with a polycrystalline diamond tool. Measurement, 45(6), 1367-1379. https://doi.org/10.1016/j.measurement.2012.03.030
[12] Feng, D., Shen, M.-x., Peng, X.-d., & Meng, X.-k. (2017). Surface roughness effect on the friction and wear behaviour of acrylonitrile–butadiene rubber (NBR) under oil lubrication. Tribology Letters, 65(1), 1-14. https://doi.org/10.1007/s11249-016-0793-5
[13] Hecht, K., Messerschmidt, F., Pfeifer, P., Dittmeyer, R., Kraushaar-Czarnetzki, B., & Hecht, S. (2013). Surface roughness of machined microchannels and its effect on multiphase boundary conditions. Chemical Engineering Journal, 227, 2-12. https://doi.org/10.1016/j.cej.2012.11.127
[14] Aldwell, B., O’Mahony, J., & O’Donnell, G. E. (2015). The Effect of Workpiece Cooling on the Machining of Biomedical Grade Polymers. Procedia CIRP, 33, 305-310. https://doi.org/10.1016/j.procir.2015.06.058
[15] Campos Rubio, J. C., Panzera, T. H., & Scarpa, F. (2015). Machining behaviour of three high-performance engineering plastics. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 229(1), 28-37. https://doi.org/10.1177/0954405414525142
[16] Kakinuma, Y., Kidani, S., & Aoyama, T. (2012). Ultra-precision cryogenic machining of viscoelastic polymers. CIRP Annals, 61(1), 79-82. https://doi.org/10.1016/j. cirp.2012.03.039
[17] Amini, S., Baraheni, M., & Moeini Afzal, M. (2018). Statistical study of the effect of various machining parameters on delamination in drilling of carbon fiber reinforced composites. Journal of Science and Technology of Composites, 5(1), 41-50. https://doi.org/10.22068/jstc.2018.28562
[18] Azad Hassan, M., Shakouri, E., & Saraeian, P. (2017). Investigation of Surface Roughness in Turning of Epoxy-Glass Composite Tubes. Modares Mechanical Engineering, 16(12), 629-636 .
[19] Ghosh, R., Knopf, J. A., Gibson, D. J., Mebrahtu, T., & Currie, G. (2007, September). Cryogenic machining of polymeric biomaterials: An intraocular lens case study. Medical Device Materials IV: Proceedings of the Materials &Processes for Medical Devices Conference 2007, USA. https://www.researchgate.net/ publication/272494251_Cryogenic_Machining_of_Polymeric_Biomaterials_An_Intraocular_Lens_Case_Study?enrichId=rgreq-1ae115a3a1583e145610b5333098c e34-XXX&enrichSource=Y292ZXJQYWdlOzI3MjQ5NDI1MTtBUzoxOTg4Nz Q1NzM2MTEwMDhAMTQyNDQyNjgwMTY0OA%3D%3D&el=1_x_2&_esc=publicationCoverPdf
[20] Morkavuk, S., Köklü, U., Bağcı, M., & Gemi, L. (2018). Cryogenic machining of carbon fiber reinforced plastic (CFRP) composites and the effects of cryogenic treatment on tensile properties: A comparative study. Composites Part B: Engineering, 147, 1-11. https://doi.org/10.1016/j.compositesb.2018.04.024
[21] Palanikumar, K., & Paulo Davim, J. (2007). Mathematical model to predict tool wear on the machining of glass fibre reinforced plastic composites. Materials & Design, 28(7), 2008-2014. https://doi.org/10.1016/j.matdes.2006.06.018
[22] Petropoulos, G., Mata, F., & Davim, J. P. (2008). Statistical study of surface roughness in turning of peek composites. Materials & Design, 29(1), 218-223. https://doi.org/10.1016/j.matdes.2006.11.005
[23] Xiao, K. Q., & Zhang, L. C. (2002). The role of viscous deformation in the machining of polymers. International Journal of Mechanical Sciences, 44(11), 2317-2336. https://doi.org/10.1016/S0020-7403(02)00178-9
[24] Turner, J., Scaife, R. J., & El-Dessouky, H. M. (2015). Effect of machining coolant on integrity of CFRP composites. Advanced Manufacturing: Polymer & Composites Science, 1(1), 54-60. https://doi.org/10.1179/2055035914Y.0000000008
[25] Di Lorenzo, S., Di Paola, M., La Mantia, F. P., & Pirrotta, A. (2017). Non-linear viscoelastic behavior of polymer melts interpreted by fractional viscoelastic model. Meccanica, 52(8) ,1843-1850 .https://doi.org/10.1007/s11012-016-0526-8
[26] Tan, B., & Stephens, L. S. (2019). Evaluation of viscoelastic characteristics of PTFE-Based materials. Tribology International, 140, 105870. https://doi.org/10.1016/j. triboint.2019.105870
[27] Wang, H., Sun, J., Li, J., Lu, L., & Li, N. (2016). Evaluation of cutting force and cutting temperature in milling carbon fiber-reinforced polymer composites. The International Journal of Advanced Manufacturing Technology, 82(9-12), 1517-1525. https://doi.org/10.1007/s00170-015-7479-2
[28] Dandekar, C. R., & Shin, Y. C. (2012). Modeling of machining of composite materials: A review. International Journal of Machine Tools and Manufacture, 57, 102-121. https://doi.org/10.1016/j.ijmachtools.2012.01.006
[29] Nicholson, J. (2017). The chemistry of polymers. Royal Society of Chemistry. https://pubs.rsc.org/en/content/ebook/978-1-78262-832-3
[30] Calleja, G., Jourdan, A., Ameduri, B., & Habas, J.-P. (2013). Where is the glass transition temperature of poly(tetrafluoroethylene)? A new approach by dynamic rheometry and mechanical tests. European Polymer Journal, 49(8), 2214-2222. https://doi.org/10.1016/j.eurpolymj.2013.04.028
[31] Natarajan, E., Kaviarasan, V., Lim, W. H., Tiang, S. S., Parasuraman, S., & Elango, S. (2020). Non-dominated sorting modified teaching–learning-based optimization for multi-objective machining of polytetrafluoroethylene (PTFE). Journal of Intelligent Manufacturing, 31(4), 911-935. https://doi.org/10.1007/s10845-019-01486-9
[32] Tomkovic, T., & Hatzikiriakos, S. G. (2020). Rheology and processing of polytetrafluoroethylene (PTFE) paste. The Canadian Journal of Chemical Engineering, 98(9), 1852-1865. https://doi.org/10.1002/cjce.23816
[33] Theiler, G., Hübner, W., Gradt, T., Klein, P., & Friedrich, K. (2002). Friction and wear of PTFE composites at cryogenic temperatures11Extended version of the paper presented at the 2nd World Tribology Congress, Vienna, 3–7 September 2001. Tribology International, 35(7), 449-458. https://doi.org/10.1016/S0301-679X(02) 00035-X
[34] Knight, W. A., & Boothroyd, G. (2005). Fundamentals of metal machining and machine tools. CRC Press. https://www.routledge.com/Fundamentals-of-Metal-Machining-and-Machine-Tools/Knight-Boothroyd/p/book/9781574446593
[35] Karimzad Ghavidel, A., Navidfar, A., Shabgard, M., & Azdast, T. (2016). Role of CO2 laser cutting conditions on anisotropic properties of nanocomposite contain carbon nanotubes. Journal of Laser Applications, 28(3), 032006. https://doi.org/10.2351/1.4947491
[36] Karimzad Ghavidel, A., Shabgard, M., & Biglari, H. (2016). Microscopic and mechanical properties of semi-crystalline and amorphous polymeric parts produced by laser cutting. Journal of applied polymer science, 133(44). https://doi.org/10.1002/app.44179
[37] Chung, D. (2001). Materials for vibration damping. Journal of materials science, 36(24), 5733-5737. https://link.springer.com/article/10.1023/A:1012999616049
[38] Lalwani, D. I., Mehta, N. K., & Jain, P. K. (2008). Experimental investigations of cutting parameters influence on cutting forces and surface roughness in finish hard turning of MDN250 steel. Journal of Materials Processing Technology, 206(1), 167-179. https://doi.org/10.1016/j.jmatprotec.2007.12.018
[39] Grisorio, R., Suranna, G. P., Mastrorilli, P., & Nobile, C. F. (2007). Insight into the Role of Oxidation in the Thermally Induced Green Band in Fluorene-Based Systems. Advanced Functional Materials, 17(4), 538-548. https://doi.org/10.1002/ adfm.200600083
[40] Rivas, F. J., Beltrán, F. J., Gimeno, O., & Carbajo, M. (2006). Fluorene Oxidation by Coupling of Ozone, Radiation, and Semiconductors: A Mathematical Approach to the Kinetics. Industrial & Engineering Chemistry Research, 45(1), 166-174. https://doi.org/10.1021/ie050781i