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Poli-fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri ile Mika ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme ve Aşınma Davranışları

Year 2023, , 439 - 446, 31.12.2023
https://doi.org/10.7240/jeps.1289110

Abstract

Bu çalışmada, katkısız Poliamit (PA6) polimeri ile ağırlık olarak %20 oranında mika katkılı Poliamit 6 (PA6/20M) ve %20 oranında mika/%10 oranında cam elyaf (CE) katkılı Poliamit 6 (PA6/20M/10CE) kompozitlerin tribolojik özellikleri incelenmiştir. Kompozit granül üretimi için önce çift vidalı ekstruder kullanılmış, test numuneleri üretimi için ise enjeksiyon makinası kullanılmıştır. Aşınma ve sürtünme testleri kuru ortam şartları altında %40 kısa cam elyaf takviyeli Poli-fenilen-Sülfit (PPS/40CE) kompozit diskine karşı yapılmıştır. Aşınma deneyleri pim-disk aşınma test cihazı kullanılarak oda sıcaklığında gerçekleştirilmiştir. Triboloji deneylerinde üç farklı yük (10-20-30 N) ve 0.5m/s sabit kayma hızı kullanılmıştır. Çalışma şartları alrındaki malzemelerin sürtünme katsayısı ve aşınma hacmi değişimi belirlenmiştir. Çalışma sonucunda uygulanan yükün artması ile katkısız PA6 polimeri ile PA6/20M ve PA6/20M/10CE kompozitlerinin sürtünme katsayısı sırasıyla %25.2, %29.6 ve %15.2 oranlarında artış göstermiştir. PA6 polimeri ilave edilen %20 oranındaki mika katkısı sürtünme katsayısını %33.0 oranında artırmıştır. PA6/20M kompozitine ilave edilen %10 oranındaki cam elyaf ise sürtünme katsayısını %86.1 oranında azaltmıştır. Uygulanan yükün artırılması ile katkısız PA6 polimerinin aşınma hacmi %200 oranında artarken PA6/20M kompozitinde %291.3 oranında artmıştır. Buna ilaveten PA6/20M/10CE hibrit kompoziti ise %371.4 oranında artmıştır. Deneyler sonucunda en az aşınma hacmi diğer kombinasyonlarla kıyaslandığında minimum %20 oranında PA6/20M-10CE/PPS-40CE kombinasyonunda elde edilmiştir.

References

  • [1] Sathees Kumar, S., & Kanagaraj, G., (2016). Investigation on mechanical performances of PA6 and Al2O3 reinforced pa6 polymer composites. International Journal of Advanced Engineering Technology, VII(I), 69-74.
  • [2] Unal, H., Saylan, T., & Mimaroglu, A., (2014). Thermal, mechanical and tribological performance of polymer composites rubbed against polymer composites in application in electrical contact breakers. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 228(6), 608–615.
  • [3] Gyorgy, C., Anna, S., & Dora, J., (2023). Effect of different fillers on thermal conductivity, tribological properties of Polyamide 6. Scientific Reports, 13, 845.
  • [4] Mariusz, W., Mirosław, S., & Daniel, P., (2022). E¬ffect of water absorption on tribological properties of thermoplastics matrix composites reinforced with glass fibres. Advances in Science and Technology Research Journal, 16(2), 232–239.
  • [5] Moustafa Mahmoud, Y.Z., Karen, S., Martin, V., & Michael, T.H., (2023). Mechanical and tribological performances of thermoplastic polymers reinforced with glass fibres at variable fibre volume fractions. Polymers, 15, 694.
  • [6] Yi, W., & Jun, T., (2021). Development of carbon fiber-reinforced thermoplastics for mass-produced automotive applications in Japan. Journal of Composites Science, 5, 86.
  • [7] Dipen, K.R., Pratiksha, H.W., & Emanoil, L., (2021). Manufacturing technologies of carbon/glass fiber-reinforced polymer composites and their properties: A Review. Polymers, 13, 3721.
  • [8] Nuruzzaman, D.M., Iqbal Asif, A.K.M., Oumer, A.N., Ismail, N.M. & Basri, S., (2016). Experimental investigation on the mechanical properties of glass fiber reinforced nylon. IOP Conf. Series: Materials Science and Engineering, 114, 012118.
  • [9] Zaldua N., Jon M., Amaia de la C., Sonia G.A., Cristina E., Isabel H., Agnieszka T., & Alejandro J.M., (2019). Nucleation and crystallization of PA6 composites prepared by T-RTM: Effects of carbon and glass fiber loading. Polymers, 11, 1680.
  • [10] Fahmi, A., Jawaid, M., Hassan, A., & Wahit, M.U., (2013). Mechanical properties of mica-filled Polycarbonate/Poly(Acrylonitrile-Butadiene-Styrene) composites. Polymer-Plastics Technology and Engineering, 52, 727-736.
  • [11] Lubomir, L., David, M., Barbora, L., Martin, V., Michal, S., Klara, C., Jakub, V., Kristian, E.W., Richard, W.G., & Neil, A.R., (2018). Effect of filler particle shape on plastic-elastic mechanical behaviour of high density poly (ethylene)/mica and poly (ethylene)/wollastonite composites. Composites Part B, 141, 92-99.
  • [12] Deshmukh, S.P., & Rao, A.C., (2012). Mica filled PVC composites: Performance enhancement in dielectric and mechanical properties with treated/untreated mica of different particle size and different concentration. Journal of Minerals & Materials Characterization & Engineering, 11(2), 169-181.
  • [13] Suryasarathı, B., & Mahanwar, P.A., (2005).Influence of particle size and particle size distribution on MICA filled nylon 6 composite. Journal of Materıals Science, 40, 6423–6428.
  • [14] Sreekanth, M.S., Joseph, S., Mhaske, S.T. & Mahanwar, P.A., (2011). Effects of mica and fly ash concentration on the properties of polyester Thermoplastic Elastomer Composites. Journal of Thermoplastic Composıte Materials, 24, 317-331.
  • [15] Suryasarathi, B., & Mahanwar, P.A. (2004). Effect of Particle Size of Filler on Properties of Nylon-6. Journal of Minerals & Materials Characterization & Engineering, 3(1), 23-31.
  • [16] Unal, H., & Mimaroglu, A., (2012). Mechanical and Morphological Properties of Mica and Short Glass Fiber Reinforced Polyamide 6 Composites. International Journal of Polymeric Materials, 61, 834-846.
  • [17] Gan, D., Lu, S., Caisheng, S. & Zhijian, W. (2001). Mechanical properties and frictional behaviour of a mica-filled poly (aryl ether ketone) composites. European Polymer Journal, 37, 1359-1365.
  • [18] Pogacnik, A., Kupec, A. & Kalin, M. (2017). Tribological properties of polyamide (PA6) inself-mated contacts and against steel as a stationary and moving body. Wear, 378-379, 17–26.
  • [19] Unal, H., Abdullah, M. & Ahmet, O. (2017). Friction and wear performance of glass fiber reinforced poly-ether-ether-ketone composite against different polymer counterparts. MOJ Polymer Science, 1(5), 188-190.
  • [20] Demir, Z., (2013). Tribological performance of polymer composites used in electrical engineering applications. Bulletin of Materials Science, 36(2), 341-344.
  • [21] Unal, H., Mimaroglu, A. & Serdar, V. (2006). Dry sliding performance of thermoplastics against reinforced unsaturated polyester (BMC): In use in electrical contact breakers components. Wear, 261, 841–847.
  • [22] Samyn, P., De Baets, P. & Schoukens, G. (2009). Influence of internal lubricants (PTFE and silicon oil) in short carbon fibre-reinforced polyimide composites on performance properties. Tribology Letters, 36(2), 135-146.
  • [23] Wei, L., Qi, L., Yi, L., Shengtai, Z., Huawei, Z., & Mei, L. (2016). Enhanced mechanical and tribological properties in polyphenylene sulfide/polytetrafluoroethylene composites reinforced by short carbon fiber. Composites Part B, 91, 579-588
  • [24] Shaofeng, Z., Qiaoxin, Z., Chaoqun W., & Jin H. (2013). Effect of carbon fiber reinforcement on the mechanical and tribological properties of polyamide6/polyphenylene sulfide composites. Materials and Design, 44, 493–499.
  • [25] Yi-Lan, Y., Du-Xin, L., Gao-Jie, S., Ruo-Yun, L., & Xin, D., (2016). Improvement in the tribological properties of polyamide 6: Talc, glass fiber, graphite, andultrahigh-molecular-weight polyethylene. Journal of Thermoplastic Composite Materials, 29(4), 494–507.
  • [26] Chukov, D. I., Stepashkin, A.A., Maksimkin, A.V., Tcherdyntsev, V.V., Kaloshkin, S. D., Kuskov, K.V., & Bugakov, V.I., (2015). Investigation of structure, mechanical and tribological properties of short carbon fiber reinforced UHMWPE-matrix composites. Composites Part B, 76, 79-88.
  • [27] Li, D. X., Xie, Y., Li, W.J., Yilan, Y., & Xin. D., (2013). Tribological and mechanical behaviors of polyamide 6/glass fiber composite filled with various solid lubricants. The Scientific World Journal, 2013, 320837.
  • [28] Unal H, Kaya U.A., Esmer K, Mimaroglu, A, Poyraz, B., (2016). Influence of wax content on the electrical, thermal and tribological behaaviour of a polyamide 6/graphite composite, J Polymer Engineering, 36(3), 279–286.
  • [29] https://www.solvay.com/sites/g/files/srpend221/files/2018-08/Ryton-PPS-Types_EN-v1.2_0.pdf
  • [30] Autay, R., Missaoui, S., Mars, J., & Dammak, F., (2019). Mechanical and tribological study of short glass fiber-reinforced PA 66. Polymers and Polymer Composites, 27(9), 587–596.
  • [31] Venkatesan, M., Palanıkumar, K., & Rajendra Boopathy, S., (2017). Experimental investigation and analysis on the wear properties of glass fiber and CNT reinforced hybrid polymer composites. Science Engineering Composite Materials, 1-12.
  • [32]Kunishima, T., Yasuharu, N., Setsuo, N., Takanori, K., Gaetan, B., Jean-Christophe, A., Vincent, F., & Philippe, K. (2020). Effects of glass fiber properties and polymer molecular mass on the mechanical and tribological properties of a polyamide-66-based compositein contact with carbon steel under grease lubrication. Wear, 462-463,203500.

Friction and Wear Behavior of Polyamide-6 Polymer and Mica and Glass Fiber Reinforced Polyamide-6 Polymer Composites against Poly-phenylene-Sulfide Polymer Composite

Year 2023, , 439 - 446, 31.12.2023
https://doi.org/10.7240/jeps.1289110

Abstract

In this study, the tribological properties of Polyamide 6 (PA6), and Polyamide 6 composites with 20% mica by weight, (PA6/20M) and PA6 composite with 20%mica filler and 10% glass fiber (GF) by weight (PA6/20M/10GF) additives were investigated. A twin screw extruder was used for the production of composite granules and an injection molding machine was used for the production of test specimens. Wear and friction tests were performed under dry sliding conditions against a 40wt.% short glass fiber reinforced Poly-phenylene-Sulfide (PPS/40GF) composite disc. Wear tests were carried out at room temperature using a pin-disc wear test rig. Three different loads (10-20-30 N) and a constant sliding speed of 0.5m/s were used in the tribology experiments. The friction coefficient and wear volume changes of the materials under the operating conditions were determined. As a result, the coefficient of friction of PA6 polymer, PA6/20M and PA6/20M/10CE composites increased by 25.2%, 29.6% and 15.2%, respectively, with the increase in the applied load. The addition of 20% mica to PA6 polymer increased the coefficient of friction by 33.0%. The addition of 10% glass fiber to PA6/20M composite decreased the coefficient of friction by 86.1%. the coefficient of friction increases with the increase in applied load for unfilled PA 6 polymer and PA6/20M and PA6/20M/10CE composites increased by 25.2%, 29.6% and 15.2% respectively The addition of 20% mica to PA6 polymer increased the coefficient of friction by 33.0%, while the addition of 10% glass fiber to PA6/20M composite decreased the coefficient of friction by 86.1%. By increasing the applied load, the wear volume of the unfilled PA6 polymer increased by 200%, while the PA6/20M composite increased by 291.3%. In addition, the PA6/20M/10CE hybrid composite increased by 371.4%. As a result of the experiments, the lowest wear volume was obtained in the PA6/20M-10CE/PPS-40CE combination with a minimum of 20% ratio compared to other combinations.

References

  • [1] Sathees Kumar, S., & Kanagaraj, G., (2016). Investigation on mechanical performances of PA6 and Al2O3 reinforced pa6 polymer composites. International Journal of Advanced Engineering Technology, VII(I), 69-74.
  • [2] Unal, H., Saylan, T., & Mimaroglu, A., (2014). Thermal, mechanical and tribological performance of polymer composites rubbed against polymer composites in application in electrical contact breakers. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 228(6), 608–615.
  • [3] Gyorgy, C., Anna, S., & Dora, J., (2023). Effect of different fillers on thermal conductivity, tribological properties of Polyamide 6. Scientific Reports, 13, 845.
  • [4] Mariusz, W., Mirosław, S., & Daniel, P., (2022). E¬ffect of water absorption on tribological properties of thermoplastics matrix composites reinforced with glass fibres. Advances in Science and Technology Research Journal, 16(2), 232–239.
  • [5] Moustafa Mahmoud, Y.Z., Karen, S., Martin, V., & Michael, T.H., (2023). Mechanical and tribological performances of thermoplastic polymers reinforced with glass fibres at variable fibre volume fractions. Polymers, 15, 694.
  • [6] Yi, W., & Jun, T., (2021). Development of carbon fiber-reinforced thermoplastics for mass-produced automotive applications in Japan. Journal of Composites Science, 5, 86.
  • [7] Dipen, K.R., Pratiksha, H.W., & Emanoil, L., (2021). Manufacturing technologies of carbon/glass fiber-reinforced polymer composites and their properties: A Review. Polymers, 13, 3721.
  • [8] Nuruzzaman, D.M., Iqbal Asif, A.K.M., Oumer, A.N., Ismail, N.M. & Basri, S., (2016). Experimental investigation on the mechanical properties of glass fiber reinforced nylon. IOP Conf. Series: Materials Science and Engineering, 114, 012118.
  • [9] Zaldua N., Jon M., Amaia de la C., Sonia G.A., Cristina E., Isabel H., Agnieszka T., & Alejandro J.M., (2019). Nucleation and crystallization of PA6 composites prepared by T-RTM: Effects of carbon and glass fiber loading. Polymers, 11, 1680.
  • [10] Fahmi, A., Jawaid, M., Hassan, A., & Wahit, M.U., (2013). Mechanical properties of mica-filled Polycarbonate/Poly(Acrylonitrile-Butadiene-Styrene) composites. Polymer-Plastics Technology and Engineering, 52, 727-736.
  • [11] Lubomir, L., David, M., Barbora, L., Martin, V., Michal, S., Klara, C., Jakub, V., Kristian, E.W., Richard, W.G., & Neil, A.R., (2018). Effect of filler particle shape on plastic-elastic mechanical behaviour of high density poly (ethylene)/mica and poly (ethylene)/wollastonite composites. Composites Part B, 141, 92-99.
  • [12] Deshmukh, S.P., & Rao, A.C., (2012). Mica filled PVC composites: Performance enhancement in dielectric and mechanical properties with treated/untreated mica of different particle size and different concentration. Journal of Minerals & Materials Characterization & Engineering, 11(2), 169-181.
  • [13] Suryasarathı, B., & Mahanwar, P.A., (2005).Influence of particle size and particle size distribution on MICA filled nylon 6 composite. Journal of Materıals Science, 40, 6423–6428.
  • [14] Sreekanth, M.S., Joseph, S., Mhaske, S.T. & Mahanwar, P.A., (2011). Effects of mica and fly ash concentration on the properties of polyester Thermoplastic Elastomer Composites. Journal of Thermoplastic Composıte Materials, 24, 317-331.
  • [15] Suryasarathi, B., & Mahanwar, P.A. (2004). Effect of Particle Size of Filler on Properties of Nylon-6. Journal of Minerals & Materials Characterization & Engineering, 3(1), 23-31.
  • [16] Unal, H., & Mimaroglu, A., (2012). Mechanical and Morphological Properties of Mica and Short Glass Fiber Reinforced Polyamide 6 Composites. International Journal of Polymeric Materials, 61, 834-846.
  • [17] Gan, D., Lu, S., Caisheng, S. & Zhijian, W. (2001). Mechanical properties and frictional behaviour of a mica-filled poly (aryl ether ketone) composites. European Polymer Journal, 37, 1359-1365.
  • [18] Pogacnik, A., Kupec, A. & Kalin, M. (2017). Tribological properties of polyamide (PA6) inself-mated contacts and against steel as a stationary and moving body. Wear, 378-379, 17–26.
  • [19] Unal, H., Abdullah, M. & Ahmet, O. (2017). Friction and wear performance of glass fiber reinforced poly-ether-ether-ketone composite against different polymer counterparts. MOJ Polymer Science, 1(5), 188-190.
  • [20] Demir, Z., (2013). Tribological performance of polymer composites used in electrical engineering applications. Bulletin of Materials Science, 36(2), 341-344.
  • [21] Unal, H., Mimaroglu, A. & Serdar, V. (2006). Dry sliding performance of thermoplastics against reinforced unsaturated polyester (BMC): In use in electrical contact breakers components. Wear, 261, 841–847.
  • [22] Samyn, P., De Baets, P. & Schoukens, G. (2009). Influence of internal lubricants (PTFE and silicon oil) in short carbon fibre-reinforced polyimide composites on performance properties. Tribology Letters, 36(2), 135-146.
  • [23] Wei, L., Qi, L., Yi, L., Shengtai, Z., Huawei, Z., & Mei, L. (2016). Enhanced mechanical and tribological properties in polyphenylene sulfide/polytetrafluoroethylene composites reinforced by short carbon fiber. Composites Part B, 91, 579-588
  • [24] Shaofeng, Z., Qiaoxin, Z., Chaoqun W., & Jin H. (2013). Effect of carbon fiber reinforcement on the mechanical and tribological properties of polyamide6/polyphenylene sulfide composites. Materials and Design, 44, 493–499.
  • [25] Yi-Lan, Y., Du-Xin, L., Gao-Jie, S., Ruo-Yun, L., & Xin, D., (2016). Improvement in the tribological properties of polyamide 6: Talc, glass fiber, graphite, andultrahigh-molecular-weight polyethylene. Journal of Thermoplastic Composite Materials, 29(4), 494–507.
  • [26] Chukov, D. I., Stepashkin, A.A., Maksimkin, A.V., Tcherdyntsev, V.V., Kaloshkin, S. D., Kuskov, K.V., & Bugakov, V.I., (2015). Investigation of structure, mechanical and tribological properties of short carbon fiber reinforced UHMWPE-matrix composites. Composites Part B, 76, 79-88.
  • [27] Li, D. X., Xie, Y., Li, W.J., Yilan, Y., & Xin. D., (2013). Tribological and mechanical behaviors of polyamide 6/glass fiber composite filled with various solid lubricants. The Scientific World Journal, 2013, 320837.
  • [28] Unal H, Kaya U.A., Esmer K, Mimaroglu, A, Poyraz, B., (2016). Influence of wax content on the electrical, thermal and tribological behaaviour of a polyamide 6/graphite composite, J Polymer Engineering, 36(3), 279–286.
  • [29] https://www.solvay.com/sites/g/files/srpend221/files/2018-08/Ryton-PPS-Types_EN-v1.2_0.pdf
  • [30] Autay, R., Missaoui, S., Mars, J., & Dammak, F., (2019). Mechanical and tribological study of short glass fiber-reinforced PA 66. Polymers and Polymer Composites, 27(9), 587–596.
  • [31] Venkatesan, M., Palanıkumar, K., & Rajendra Boopathy, S., (2017). Experimental investigation and analysis on the wear properties of glass fiber and CNT reinforced hybrid polymer composites. Science Engineering Composite Materials, 1-12.
  • [32]Kunishima, T., Yasuharu, N., Setsuo, N., Takanori, K., Gaetan, B., Jean-Christophe, A., Vincent, F., & Philippe, K. (2020). Effects of glass fiber properties and polymer molecular mass on the mechanical and tribological properties of a polyamide-66-based compositein contact with carbon steel under grease lubrication. Wear, 462-463,203500.
There are 32 citations in total.

Details

Primary Language Turkish
Subjects Engineering
Journal Section Research Articles
Authors

Hüseyin Ünal 0000-0003-0521-6647

Salih Hakan Yetgin 0000-0002-6068-9204

Mustafa Güleşen 0000-0001-8781-2746

Early Pub Date December 29, 2023
Publication Date December 31, 2023
Published in Issue Year 2023

Cite

APA Ünal, H., Yetgin, S. H., & Güleşen, M. (2023). Poli-fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri ile Mika ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme ve Aşınma Davranışları. International Journal of Advances in Engineering and Pure Sciences, 35(4), 439-446. https://doi.org/10.7240/jeps.1289110
AMA Ünal H, Yetgin SH, Güleşen M. Poli-fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri ile Mika ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme ve Aşınma Davranışları. JEPS. December 2023;35(4):439-446. doi:10.7240/jeps.1289110
Chicago Ünal, Hüseyin, Salih Hakan Yetgin, and Mustafa Güleşen. “Poli-Fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri Ile Mika Ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme Ve Aşınma Davranışları”. International Journal of Advances in Engineering and Pure Sciences 35, no. 4 (December 2023): 439-46. https://doi.org/10.7240/jeps.1289110.
EndNote Ünal H, Yetgin SH, Güleşen M (December 1, 2023) Poli-fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri ile Mika ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme ve Aşınma Davranışları. International Journal of Advances in Engineering and Pure Sciences 35 4 439–446.
IEEE H. Ünal, S. H. Yetgin, and M. Güleşen, “Poli-fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri ile Mika ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme ve Aşınma Davranışları”, JEPS, vol. 35, no. 4, pp. 439–446, 2023, doi: 10.7240/jeps.1289110.
ISNAD Ünal, Hüseyin et al. “Poli-Fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri Ile Mika Ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme Ve Aşınma Davranışları”. International Journal of Advances in Engineering and Pure Sciences 35/4 (December 2023), 439-446. https://doi.org/10.7240/jeps.1289110.
JAMA Ünal H, Yetgin SH, Güleşen M. Poli-fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri ile Mika ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme ve Aşınma Davranışları. JEPS. 2023;35:439–446.
MLA Ünal, Hüseyin et al. “Poli-Fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri Ile Mika Ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme Ve Aşınma Davranışları”. International Journal of Advances in Engineering and Pure Sciences, vol. 35, no. 4, 2023, pp. 439-46, doi:10.7240/jeps.1289110.
Vancouver Ünal H, Yetgin SH, Güleşen M. Poli-fenilen-Sülfit Polimer Kompozitine Karşı Poliamit-6 Polimeri ile Mika ve Cam Elyaf Takviyeli Poliamit-6 Polimer Kompozitlerin Sürtünme ve Aşınma Davranışları. JEPS. 2023;35(4):439-46.