Abstract Recently, binder jetting additive manufacturing (BJAM) was used to manufacture complex metal parts in an economical and large-scale way. However, the usage of resin to bond metal powder renders as-printed green parts with low strength, which is potential to cause the structural damages of final parts during post treatments. To overcome the intractable problem, a self-developed binder mainly consisting of A-stage phenolic resin was explored for BJAM to achieve relatively high-strength as-printed green parts. The binder can be cured as a C-stage phenolic resin with 190 ℃ and then provide a high strength for the green parts. The effect of layer thickness and binder saturation on the strength, dimensional accuracy, and surface roughness of the BJAM-printed 316 L stainless-steel green samples using the developed binder was investigated systematically. With the optimized parameters (a layer thickness of 100 μm and a binder saturation of 30.2%), green samples can possess the ultimate bending strength (UBS) of 10.08 MPa and the ultimate compressive strength (UCS) of 25.56 MPa, which are beneficial for the structural stability of the printed samples during subsequent treatments. A reduction in strength and an increase in roughness are observed with increasing the layer thickness for the as-printed green samples. An increment in binder saturation results in the improvement in strength and surface roughness of the green samples. The relationships between the binder and the mechanical performance of the green samples were discussed from the viewpoint of the uneven distribution of binder in depth. This work explored a promising binder with a low saturation for BJAM to fabricate 316 L green parts with desirable mechanical strength and acceptable surface roughness.

中文翻译：

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具有高强度和低粘合剂含量的 316 L 不锈钢绿色部件的粘合剂喷射增材制造：粘合剂制备和工艺优化

摘要 近年来，粘合剂喷射增材制造（BJAM）被用于以经济和大规模的方式制造复杂的金属零件。然而，使用树脂来粘合金属粉末会使打印后的生坯部件强度低，这有可能在后处理过程中导致最终部件的结构损坏。为了克服这个棘手的问题，BJAM 探索了一种主要由 A 级酚醛树脂组成的自主开发的粘合剂，以实现相对高强度的印刷绿色部件。该粘合剂可在 190 ℃下固化为 C 级酚醛树脂，然后为生坯部件提供高强度。层厚和粘结剂饱和度对强度、尺寸精度、系统地研究了使用开发的粘合剂的 BJAM 印刷的 316 L 不锈钢绿色样品的表面粗糙度。优化后的参数（层厚为 100 μm，粘合剂饱和度为 30.2%），生坯样品可具有 10.08 MPa 的极限弯曲强度（UBS）和 25.56 MPa 的极限抗压强度（UCS），这有利于打印样品在后续处理过程中的结构稳定性。随着印刷的绿色样品的层厚度增加，观察到强度降低和粗糙度增加。粘合剂饱和度的增加导致生坯样品的强度和表面粗糙度的提高。从粘结剂深度分布不均的角度讨论了粘结剂与生坯力学性能的关系。这项工作探索了一种有前景的低饱和度粘合剂，用于 BJAM 制造具有理想机械强度和可接受表面粗糙度的 316 L 生坯部件。