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Investigations into the effect of thermal annealing on fused filament fabrication process

ABSTRACT The mechanical properties of fused filament-fabricated specimens are the primary considerations of researchers. Process parameters have a significant impact on the mechanical strength of 3D-printed parts. In this work, the effect of process variables such as infill volume, pattern, layer height, nozzle temperature, and print speed on tensile and compressive strength of polylactic acid samples are investigated. The maximum tensile strength of 27.87 MPa was obtained at 90% infill density for gyroid pattern of a layer thickness of 0.1 mm at a nozzle temperature of 220°C and print speed of 30 mm/s. The maximum compressive strength of 38.21 MPa was achieved at 90% infill density for the triangle pattern of a layer thickness of 0.1 mm at a nozzle temperature of 220°C and print speed of 30 mm/s. Thermal annealing as a post processing method to enhance the mechanical properties is also explored. The effect of annealing temperatures 65°C, 95°C and 125°C and time 30, 60 and 120 minutes on mechanical strength were studied. Ultimate tensile strength showed an improvement of 25.26% to achieve 34.91 MPa whereas compressive strength increased by 21.87% to give 46.57 MPa strength.