Investigation on mechanical properties of bronze infill PLA composite fabricated by fused deposition modelling

This study is on the mechanical properties of bronze infill poly lactic acid composites fabricated by fused deposition modelling. By changing the nozzle temperature, printing speed, layer thickness and infill density the mechanical properties of the composites were studied. Tensile, flexural and impact strength tests were conducted on the composite specimen. Mathematical models were developed using response surface methodology and the significance of the models was tested using analysis of variance. Increase in infill density and nozzle temperature increased the strengths of the composites. Increase in layer thickness and printing speed decreased the strengths of the composite specimen. Tensile strength is primarily influenced by infill density (38.82%), flexural strength is primarily influenced by Nozzle Temperature contributes (44.02%) while Infill density (58.12%) plays the major role in contributing the impact strength followed by other parameters. The highest tensile strength, flexural strength, impact strength values obtained in this study are 19.3 (N/mm2), 36.08 (N/mm2) and 0.26 (kJ/m2) respectively. The mechanism of the fractured specimen was investigated using scanning electron microscopy. Fracture mechanisms such as cracks, infill gaps, voids, interface, delamination, hillocks, particle pull out, delamination had an effect on the fracture of composite specimens.