3D printing offers great potential for developing complex flexure mechanisms. Recently, thickness-correction factors (TCFs) were introduced to correct the thickness and stiffness deviations of powder-based metal 3D printed flexure hinges during design and analysis. However, the reasons for the different TCFs obtained in each study are not clear, resulting in a limited value of these TCFs for future design and fabrication. Herein, the influence of the porous layer of 3D printed flexure hinges on the hinge thickness is investigated. Samples of parallelogram flexure mechanisms (PFMs) were 3D printed using selective laser melting (SLM) and 316L stainless steel powder. A 3D manufacturing error analysis was completed for each PFM sample via 3D scanning, surface roughness measurement and morphological observation. The thickness of the porous layer of the flexure hinge was independent of the designed hinge thickness and remained close to the average powder particle diameter. The effective hinge thickness could be estimated by subtracting twice the value of the porous layer thickness from the designed value. Guidelines based on finite element analysis and stiffness experiments are proposed. The limitations of the presented method for evaluating the effective hinge thickness of flexure hinges 3D printed via SLM are also discussed.

3D打印为开发复杂的弯曲机制提供了巨大的潜力。最近，引入了厚度校正因子（TCF），以在设计和分析过程中校正粉末基金属3D打印的挠性铰链的厚度和刚度偏差。但是，每个研究中获得不同TCF的原因尚不清楚，导致这些TCF在未来的设计和制造中价值有限。在此，研究了3D打印挠性铰链的多孔层对铰链厚度的影响。使用选择性激光熔化（SLM）和316L不锈钢粉末对平行四边形挠曲机构（PFM）的样品进行3D打印。通过3D扫描，表面粗糙度测量和形态观察，完成了每个PFM样品的3D制造误差分析。挠性铰链的多孔层的厚度与设计的铰链厚度无关，并保持接近平均粉末粒径。有效铰链厚度可以通过从设计值中减去多孔层厚度值的两倍来估算。提出了基于有限元分析和刚度实验的准则。还讨论了所提出的评估通过SLM打印的挠性铰链3D的有效铰链厚度的方法的局限性。提出了基于有限元分析和刚度实验的准则。还讨论了所提出的评估通过SLM打印的挠性铰链3D的有效铰链厚度的方法的局限性。提出了基于有限元分析和刚度实验的准则。还讨论了所提出的评估通过SLM打印的挠性铰链3D的有效铰链厚度的方法的局限性。