نوع مقاله : پژوهشی
نویسندگان
سمنان، دانشگاه سمنان، دانشکده مهندسی مکانیک
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Hypothesis: This study hypothesizes that applying compressive force by a roller during the Fused Filament Fabrication (FFF) 3D printing process can enhance interlayer adhesion and consequently improve the mechanical strength of parts fabricated from polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and their blend.
Methods: To examine this hypothesis, tensile test specimens were fabricated according to ASTM D638 using a modified FFF 3D printer equipped with a roller-pressure mechanism. The experiments were designed based on the Response Surface Methodology (RSM) with a Central Composite Design (CCD), including two continuous variables (printing speed and roller force) and one discrete variable (filament type). Tensile tests were conducted using a SANTAM STM-400 machine at a crosshead speed of 5 mm/min. The fracture surfaces were analyzed using a Field Emission Scanning Electron Microscope (FESEM). The data were processed using Design-Expert 13 software to evaluate the main and interaction effects of the parameters on tensile strength.
Findings: Analysis of variance (ANOVA) revealed that the filament type and its interaction with roller force had a statistically significant effect on tensile strength (p < 0.05). The applied compressive force improved interlayer bonding, reduced layer thickness, increased the raster shear angle, and promoted polymer chain alignment along the load direction, leading to enhanced tensile performance. Under optimized conditions, the maximum tensile strengths of PLA, ABS, and PLA/ABS samples were 58.8, 34.7, and 45.2 MPa, respectively, corresponding to an improvement of up to 10.9% compared to samples printed without roller pressure. FESEM observations further confirmed the reduced layer thickness and improved interlayer fusion. Overall, the application of roller force during FFF printing effectively enhances the strength and quality of printed components without the need for post-processing treatments.
کلیدواژهها [English]
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