Abstract To facilitate functional part production in metal binder jetting additive manufacturing, the relationship between materials, process and sintering needs to be understood. This work relates sintering theory with process outcomes. For this, commercially pure titanium was deployed to study the effect of powder size distributions on green and sintered part qualities (bulk density, relative density, particle size, pore size, sinter neck size). The powders were uni- and bi-modal blends of 0–45 μm, 45–106 μm, and 106–150 μm. Computed tomography analysis was used to evaluate non-densifying (1000 °C) and densifying (1400 °C) sintering regimes. For green parts, the relative density and powder size distribution along the build direction followed a periodic fluctuation equivalent to the 150 μm layer thickness. The relative density fluctuation range was higher (±20%) for bi-modal blends with 0–45 μm, compared to all other blends (±8%) due to powder segregation. For non-densifying sintering, parts with 0–45 μm blends displayed both densifying and non-densifying behavior. For densifying sintering, powders containing 0–45 μm blends surpassed the 70% density threshold expected for this sintering regime. Overall, the finer particles improved bulk density of sintered parts, at the expense of higher levels of shrinkage and density anisotropy along the build direction.

中文翻译：

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粘结剂喷射增材制造钛结构的烧结结构分析

摘要 为了促进金属粘合剂喷射增材制造中的功能部件生产，需要了解材料、工艺和烧结之间的关系。这项工作将烧结理论与过程结果联系起来。为此，使用商业纯钛来研究粉末尺寸分布对生坯和烧结零件质量（体积密度、相对密度、粒度、孔径、烧结颈尺寸）的影响。粉末是 0-45 μm、45-106 μm 和 106-150 μm 的单峰和双峰混合物。计算机断层扫描分析用于评估非致密 (1000 °C) 和致密 (1400 °C) 烧结制度。对于生坯部件，沿构建方向的相对密度和粉末尺寸分布遵循相当于 150 μm 层厚度的周期性波动。由于粉末偏析，与所有其他混合物 (±8%) 相比，0-45 μm 双峰混合物的相对密度波动范围更高 (±20%)。对于非致密化烧结，具有 0-45 μm 混合物的零件显示出致密化和非致密化行为。对于致密烧结，含有 0-45 μm 混合物的粉末超过了该烧结方案预期的 70% 密度阈值。总体而言，更细的颗粒提高了烧结部件的堆积密度，但代价是沿构建方向的收缩率和密度各向异性水平更高。含有 0-45 μm 混合物的粉末超过了该烧结方案预期的 70% 密度阈值。总体而言，更细的颗粒提高了烧结部件的堆积密度，但代价是沿构建方向的收缩率和密度各向异性水平更高。含有 0-45 μm 混合物的粉末超过了该烧结方案预期的 70% 密度阈值。总体而言，更细的颗粒提高了烧结部件的堆积密度，但代价是沿构建方向的收缩率和密度各向异性水平更高。