本文提出的研究涉及用于潜在生物医学应用的两种常见聚合物的机械性能,PLA和PETG,通过熔丝制造(FFF)-材料挤出(ME)处理。对于进行的单轴拉伸试验,两个打印方向-XY(水平,H)和YZ(垂直,V)-根据零件定位的一般原则考虑,坐标,和取向通常用于增材制造(AM)。此外,对每种印刷方向和材料测试了六个样品,提供对机械性能的见解,如拉伸强度,杨氏模量,和终极应变,表明材料的生物医学应用潜力。然后将实验结果与从文献中获得的其他聚合物如ASA的相应机械性能进行比较,PC,PP,ULTEM9085,共聚酯,和尼龙。此后,PLA和PETG的疲劳阻力曲线(S-N曲线),沿45°印刷,在室温下确定负荷比,R,0.2。扫描电子显微镜观察显示纤维排列,层之间的压缩/粘合,和断裂带,阐明此类材料的疲劳裂纹扩展所涉及的失效机理,并为将来的应用提供设计参考值。此外,进行了疲劳断裂面的断口分析,以及X射线计算机断层扫描(XCT)和热重(TGA)/差示扫描量热(DSC)测试。
The study presented herein concerns the mechanical properties of two common polymers for potential biomedical applications, PLA and PETG, processed through fused filament fabrication (FFF)-Material Extrusion (ME). For the uniaxial tension tests carried out, two printing orientations-XY (Horizontal, H) and YZ (Vertical, V)-were considered according to the general principles for part positioning, coordinates, and orientation typically used in additive manufacturing (AM). In addition, six specimens were tested for each printing orientation and material, providing insights into mechanical properties such as Tensile Strength, Young\'s Modulus, and Ultimate Strain, suggesting the materials\' potential for biomedical applications. The experimental results were then compared with correspondent mechanical properties obtained from the literature for other polymers like ASA, PC, PP, ULTEM 9085, Copolyester, and Nylon. Thereafter, fatigue resistance curves (S-N curves) for PLA and PETG, printed along 45°, were determined at room temperature for a load ratio, R, of 0.2. Scanning electron microscope observations revealed fibre arrangements, compression/adhesion between layers, and fracture zones, shedding light on the failure mechanisms involved in the fatigue crack propagation of such materials and giving design reference values for future applications. In addition, fractographic analyses of the fatigue fracture surfaces were carried out, as well as X-ray Computed Tomography (XCT) and Thermogravimetric (TGA)/Differential Scanning Calorimetric (DSC) tests.