Fracture morphology and strength characteristics of poly-lactic acid and poly-ethylene terephthalate glycol composites combined with taguchi method and response surface methodology

The emergence of additive manufacturing has enabled scientists to efficiently construct complex geometries, facilitating the development of novel, high-impact energy-absorbing structures suitable for a wide range of industrial applications. The present study conducted flexural and impact test to quantitatively assess the energy absorption capabilities of polymer composites fabricated through fused filament fabrication. Specifically, the polymer composites investigated were multi-walled carbon nanotubes reinforced poly-lactic acid, carbon fibre reinforced poly-ethylene terephthalate glycol, and carbon fibre reinforced poly-lactic acid. The investigation also examined the influence of different infill patterns and nozzle hole diameters on the polymer composites. The investigation depicts that by altering the process parameters, the flexural strength is improved from 21.079 MPa to 70.653 MPa by 235.18%. The experimental study of impact specimens utilising the Izod impact test demonstrates that the rectilinear infill pattern and a nozzle hole diameter of 0.6 mm result in the highest energy absorption of 37.76 kJ/m2 for carbon fibre reinforced poly-lactic acid. The study revealed that the energy absorption of the specimens was significantly influenced by both the independent and interaction effects of process variables. The application of the fused filament fabrication demonstrates an improved energy absorption, making it suitable for manufacturing of vehicle and aircraft components.