The Effect of Heat Treatment on the Mechanical Properties of Continuously Fibre-Reinforced Standardised Specimens

Year 2025, Volume: 9 Issue: Special Issue 1st Future of Vehicles: Innovation, Engineering and Economic Conference, 22 - 27

Balázs Molnár , Róbert Magai

Abstract

This study investigates the influence of post-printing heat treatments on the mechanical characteristics of 3D-printed specimens strengthened with continuous Kevlar filaments. After their fabrication, the specimens underwent thermal annealing at temperatures of 100 °C and 150 °C for either 1 or 3 hours. To assess the effects of these treatments on mechanical performance, tensile tests and microscopic analyses were performed. The findings indicated that the most significant enhancement was observed in specimens annealed at 150 °C for 1 hour, which resulted in an approximately 20% increase in tensile strength compared to untreated samples. Heat treatments at 100 °C for 1 hour and 3 hours led to moderate improvements of 5–8%, whereas extended treatment at 150 °C for 3 hours resulted in a reduction of about 10% in tensile strength. Microscopy revealed that brief, high-temperature treatment enhanced interlayer bonding and decreased internal stress without harming the structure, while prolonged thermal exposure led to local delamination and compromised fibre–matrix adhesion. These results suggest that controlled post-printing heat treatment can enhance the mechanical properties of continuous fibre-reinforced composites, though excessive heat exposure can lead to degradation. Therefore, careful optimisation of temperature and duration is crucial. The outcomes offer valuable insights for improving the structural performance of additively manufactured continuous fibre-reinforced components.

Keywords

Additive manufacturing , Continouos fiber 3D printing , Heat treatment , Microstructural analysis , Tensile

References

• [1] Sai Kalyan MV., Kumar H, Nagdeve L. Latest trends in Additive manufacturing. IOP Conf Ser Mater Sci Eng. 2021;1104(1):012020. https://doi.org/doi:10.1088/1757-899X/1104/1/012020
• [2] Zhou L, Miller J, Vezza J, Mayster M, Raffay M, Justice Q, et al. Additive Manufacturing: A Comprehensive Review. Sensors. 2024;24(9). https://doi.org/10.3390/s24092668
• [3] Srivastava M, Rathee S, Patel V, Kumar A, Koppad PG. A re-view of various materials for additive manufacturing: Recent trends and processing issues. J Mater Res Technol. 2022;21:2612–41. https://doi.org/10.1016/j.jmrt.2022.10.015
• [4] Negi S, Sharma RK. Basics , Applications And Future Of Addi-tive Manufacturing Technologies : A Review,J Manuf Technol Res. 2016; 5 (1/2): 75-96.
• [5] Kumar R, Kumar M, Chohan JS. The role of additive manufactur-ing for biomedical applications: A critical review. J Manuf Pro-cess 828–50. https://doi.org/10.1016/j.jmapro.2021.02.022
• [6] Kamble AV. A Review Article on 3D Printing Technology and Its Medical Applications. Interional J Aquat Sci. 2023;14(01):375–80. https://doi.org/10.1016/j.eng.2018.07.021
• [7] Al-maliki JQ, Al-maliki AJQ. The Processes and Technologies of 3D Printing. Int J Adv Comput Sci Technol 2015;4(10):161–165.
• [8] Gokhare V, Raut D, Shinde D. A Review paper on 3D-Printing and Various Processes Used in the 3D-Printing. Interantional J Sci Res Eng Manag. 2017;6(6):953–958.
• [9] Lim HW, Cassidy T. 3D Printing Technology Revolution in Fu-ture Sustainable Fashion. 2014 Int Text Costume Cult Congr 2014; 25-26 Oct, South Korea.
• [10] Shahrubudin N, Lee TC, Ramlan R. An overview on 3D printing technology: Technological, materials, and applications. Procedia Manuf. 2019;35:1286–96. https://doi.org/10.1016/j.promfg.2019.06.089
• [11] Mulay AA, More SD, Mhetre RL, Society’s, PE. A Review on 3D Printing Technologies in Pharmaceutical Science. Env Phar-macol Life Sci. 2020;9(August):126–34. https://doi.org/10.3390/pharmaceutics15020416
• [12] Zhang D, Tian X, Zhou Y, Wang Q, Yan W, Akmal Zia A, et al. Spatial 3D Printing of Continuous Fiber-Reinforced Composite Multilayer Truss Structures with Controllable Structural Perfor-mance. Polymers (Basel). 2023;15(21). https://doi.org/10.3390/polym15214333
• [13] Min S, Tan Y, Zhang F, Tu Y. 3D printing process for continu-ous fibre reinforced composites with variable deposition direction. Adv Mech Eng. 2023;15(8):1–14. https://doi.org/10.1177/16878132231190341
• [14] Hou Z, Tian X, Zhang J, Zhe L, Zheng Z, Li D, et al. Design and 3D printing of continuous fiber reinforced heterogeneous compo-sites. Compos Struct 2020;237 (January):111945 https://doi.org/10.1016/j.compstruct.2020.111945
• [15] He X, Ding Y, Lei Z, Welch S, Zhang W, Dunn M, et al. 3D printing of continuous fiber-reinforced thermoset composites. Addit Manuf. 2021;40(November 2020). https://doi.org/10.1016/j.addma.2021.101921
• [16] Yang Y, Yang B, Chang Z, Duan J, Chen W. Research Status of and Prospects for 3D Printing for Continuous Fiber-Reinforced Thermoplastic Composites. Polymers (Basel). 2023;15(17). https://doi.org/10.3390/polym15173653
• [17] Cofaru NF, Pascu A, Oleksik M, Petruse R. Tensile Properties of 3D-printed Continuous-Fiber-Reinforced Plastics. Mater Plast. 2021;58(4):271–82. https://doi.org/10.37358/MP.21.4.5552
• [18] KARTAL F, KAPTAN A. Effects of annealing temperature and duration on mechanical properties of PLA plastics produced by 3D Printing. Eur Mech Sci. 2023;7(3):152–9. https://doi.org/10.26701/ems.1290961
• [19] Shbanah M, Jordanov M, Nyikes Z, Tóth L, Kovács T. The Effect of Heat Treatment on a 3D-Printed PLA Polymer’s Mechanical Properties. Polymers (Basel). 2023;15(6):1–12. https://doi.org/10.3390/polym15061587
• [20] Zhen H, Zhao B, Quan L, Fu J. Effect of 3D Printing Process Parameters and Heat Treatment Conditions on the Mechanical Properties and Microstructure of PEEK Parts. Polymers (Basel). 2023;15(9). https://doi.org/10.3390/polym15092209
• [21] Zisopol DG, Portoacă AI, Nae I, Ramadan IN. A Comparative Analysis of the Mechanical Properties of Annealed PLA. Eng Technol Appl Sci Res. 2022;12(4):8978–81. https://doi.org/10.48084/etasr.5123
• [22] Zisopol DG, Portoaca AI, Tanase M. Improving the Impact Re-sistance through Annealing in PLA 3D Printed Parts. Eng Tech-nol Appl Sci Res. 2023;13(5):11768–72. https://doi.org/10.48084/etasr.6281
• [23] Kulcsár K, Kónya J. The Influence of Heat Treatment on the Me-chanical Properties of 3D-Printed Cobalt-Chrome Alloy Used in Dental Laboratory Practice. Acta Mater Transilv. 2018;1(1):97–100
• [24] ASTM International. ASTM D638-14. 2016;
• [25] Kabir, S. M. Fiju., Kavita Mathur, and Abdel Fattah M. Seyam. “The Road to Improved Fiber-Reinforced 3D Printing Technolo-gy.” Technologies. 2020;8(4). https://doi.org/10.3390/technologies8040051