Impact of binder on part densification: Enhancing binder jetting part properties through the fabrication of shelled geometries
Impact of binder on part densification: Enhancing binder jetting part properties through the fabrication of shelled geometries
复制标题
粘合剂对零件致密化的影响：通过制造壳状几何形状增强粘合剂喷射零件的性能
DOI：
10.1016/j.addma.2022.103377
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发表时间：
2023
影响因子：
11
通讯作者：
Williams, Christopher B.
中科院分区：
文献类型：
--
作者：
Rahman, Kazi Moshiur;Wei, Amanda;Miyanaji, Hadi;Williams, Christopher B.
在粘结剂喷射（BJT）增材制造（AM）中，喷射的液体粘结剂粘结粉末颗粒并为打印的绿色部件提供结构完整性。印刷后，粘合剂在致密化至最终部件之前热解。虽然已经探索了粘结剂饱和度对绿色零件质量的影响，但是粘结剂对零件致密化和随后的零件性能的影响的研究是有限的。在这项研究中，粘结剂对致密化的影响进行了研究，通过一种新的方法，粘结剂喷射称为“壳打印”，以改变量的粘结剂含量在绿色部分。在这种方法中，粘合剂仅沉积在零件表面周围，从而有效地将填充的粉末捕获在结合的壳几何形状内。后处理烧结可巩固结合（打印外壳）和未结合粉末，并使部件致密化。壳厚度的操纵使得能够探索粘结剂含量对工艺-结构-性能关系的影响。使用纯铜作为示例材料，并分析具有不同壳厚度的部件，发现与均匀粘合剂放置的传统策略相比，壳印刷显著影响绿色部件密度（增加3.7%）、最终部件密度（增加1.5%）、晶粒尺寸（增加1.290%）和拉伸强度（增加8.84%）。虽然传统的粘合方法提高了绿色部件强度并减少了烧结过程中的部件塌陷，但与壳印刷方法相比，它也阻碍了致密化，限制了晶粒生长，并在晶界处引起孔隙。
In binder jetting (BJT) additive manufacturing (AM), jetted liquid binder binds powder particles and provides structural integrity to the printed green parts. Following printing, the binder is pyrolyzed before densification to final part. While the effects of binder saturation on the green part quality have been explored, the study of the impact of binder on part densification and subsequent part properties is limited. In this study, the impact of binder on densification is studied through a new approach of binder jetting termed as “shell printing” to vary the amount of binder content in a green part. In this approach, binder is only deposited around the part surface, which effectively traps packed powders inside the bound shell geometry. Post-process sintering consolidates both bound (printed shell) and unbound powders and densifies the part. Manipulation of the shell thickness enables exploration of the effects of binder content on process-structure-property relationships. Using pure copper as an exemplar material, and analyzing parts with varying shell thicknesses, it was found that shell printing significantly affects green part density (3.7% increase), final part density (∼5% increase), grain size (∼290% increase) and tensile strength (8.84% increase) when compared to traditional strategies of homogeneous binder placement. While the traditional binding approach improves green part strength and reduces part slumping during sintering, it also hinders densification, constrains grain growth, and induces porosity at the grain boundaries, as compared to the shell printing approach.