Nondestructive Testing of 3D Printed Fiber-Reinforced Polymeric Composites: An Experimental Critical Comparison

Area of Science:

• Additive Manufacturing
• Materials Science
• NonDestructive Testing

Background:

• Additive manufacturing of polymer matrix composites (PMCs) offers industrial potential.
• Fabrication defects in PMCs can compromise structural integrity.
• Destructive testing is common, but reliable non-destructive testing (NDT) is crucial for quality control.

Purpose of the Study:

• To benchmark four NDT techniques for inspecting 3D printed PMCs.
• To evaluate defect detection capabilities in polylactic acid composites reinforced with Kevlar®, carbon, and glass fibers.
• To assess techniques for automated, non-contact imaging inspection.

Main Methods:

• 3D printing of PMC samples using fused filament fabrication with polylactic acid matrix.
• Inclusion of artificial defects (0.5 mm thick delaminations).
• Evaluation of active pulse thermography, air-coupled ultrasound, continuous wave terahertz, and digital X-ray.

Main Results:

• All four NDT techniques demonstrated capabilities in detecting simulated delamination defects.
• Performance varied across techniques, highlighting specific strengths and weaknesses for different defect types or material configurations.
• No single technique was universally superior for all defect characterization.

Conclusions:

• A combination of NDT techniques offers improved reliability through diversity, complementarity, and redundancy.
• Automated, non-contact NDT methods are essential for efficient and interpretable inspection of 3D printed PMCs.
• Further research should explore synergistic use of multiple NDT methods for comprehensive PMC inspection.