Investigating Process-Structure-Property Relationships in Large-Scale Additively Manufactured Carbon-Filled PETg

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• Additive manufacturing (AM) enables complex material fabrication but results in properties highly dependent on processing parameters.
• Understanding the process-structure-property relationship is crucial for optimizing AM materials.

Purpose of the Study:

• To experimentally investigate the process-structure-property linkage in carbon-fiber-reinforced PETg fabricated via large-scale additive manufacturing.
• To establish a comprehensive dataset for validating predictive models.

Main Methods:

• An experimental design with eight parameter combinations (layer height, feed rate, bead spacing, screw speed) was employed.
• Microstructure analysis (fiber orientation, porosity) and flexural testing (strength, stiffness) were performed on numerous specimens.
• High-speed photography and fractography were used to analyze fracture behavior.

Main Results:

• In-plane modulus ranged from 13.3–18.6 GPa; strength ranged from 158–189 MPa.
• Inter-layer stiffness ranged from 2.9–3.2 GPa; strength ranged from 31.4–45.0 MPa.
• Screw speed strongly correlated with fiber orientation, which directly impacted stiffness and strength.

Conclusions:

• A significant process-structure-property relationship was identified for carbon-fiber-reinforced PETg.
• The generated dataset serves as a valuable reference for AM process and material modeling.
• Screw speed is a critical parameter for controlling mechanical performance through fiber orientation.