Mechanical characterization of 3D-Printed carbon fiber-reinforced polymer composites and pure polymers: Tensile and compressive behavior analysis

Abstract

Fused deposition modeling (FDM) 3D printing is widely utilized for producing thermoplastic components with functional purposes. However, the inherent mechanical limitations of pure thermoplastic materials necessitate enhancements in their mechanical characteristics when employed in certain applications. One strategy for addressing this challenge involves the incorporation of reinforcement materials, such as carbon fiber (CF), within the thermoplastic matrix. This approach leads to the creation of carbon fiber-reinforced polymer composites (CFRPs) suitable for engineering applications. The utilization of CFRPs in 3D printing amalgamates the benefits of additive manufacturing, including customization, cost-effectiveness, reduced waste, swift prototyping, and accelerated production, with the remarkable specific strength of carbon fiber. This study encompasses tensile and compressive testing of distinct material compositions: recycled polylactic acid (rPLA), PLA enriched with 10 wt.% carbon fiber, pristine polyethylene terephthalate glycol (PETG), and PETG bolstered with 10 wt.% carbon fiber. Tensile tests adhere to the ASTM D3039 standard for specimens of rectangular shape, while the ASTM D695 standard governs the compressive testing procedures. Additionally, an inquiry into the influence of the primary 3D printing build orientation parameter on the tensile and compressive strengths of diverse materials was conducted. The outcomes reveal that rPLA exhibits superior mechanical properties in both tensile and compressive tests, irrespective of flat or on-edge build orientations. In the context of tensile strength analysis, it is noteworthy that rPLA demonstrated a superior performance, surpassing CFPLA by 30% in flat orientation and exhibiting a remarkable 39.2% advantage in on-edge orientation. Moreover, PLA reinforced with carbon fiber exhibits superior tensile and compressive properties compared to its PETG counterpart. A comparative analysis between CFPLA and CF-PETG indicates that CF-PLA demonstrates higher tensile strengths, with increases of 26.6 and 27.6% for flat and on-edge orientations, respectively. In the context of compressive strength analysis, rPLA surpassed CFPLA, PETG, and CF-PETG by 23.7, 53, and 67%, respectively. Intriguingly, the findings indicate that the incorporation of 10 wt.% carbon fiber diminishes the tensile and compressive properties in comparison to pure PETG.