Anisotropic sintering shrinkage behavior of stainless steel fabricated by extrusion-based metal additive manufacturing
Anisotropic sintering shrinkage behavior of stainless steel fabricated by extrusion-based metal additive manufacturing
复制标题
DOI：
10.1016/j.jmapro.2023.07.026
复制
发表时间：
2023-09
影响因子：
6.2
通讯作者：
S. You;Dayue Jiang;Fu-ji Wang;F. Ning
中科院分区：
文献类型：
--
作者：
S. You;Dayue Jiang;Fu-ji Wang;F. Ning
金属添加剂制造(AM)可以通过以下方法实现：首先挤出具有密集填充金属颗粒的聚合物基丝以产生所谓的“绿色”部件，然后经历脱脂和烧结以生产最终的金属部件。作为一个关键步骤，烧结控制着最终零件的形状尺寸、相对密度和合成强度。因此，对理解和量化烧结引起的各向异性收缩的研究越来越有必要。在这项工作中，将通过理论研究和实验研究相结合的方式，了解和量化挤压印刷不锈钢316L零件在整个烧结过程中的各向异性收缩行为，包括三向膨胀仪、扫描电子显微镜和X射线计算机断层扫描。通过对收缩各向异性因素的宏观分析和显微组织的表征，研究了棕色零件烧结前的三维尺寸演化。不同的填充策略将与初始孔隙分布特征相结合，以进行各向异性维度变化分析。将结合各向异性的粘性行为来讨论不均匀的气孔分布，以最终揭示烧结过程中的收缩性能。这项工作的发现将为各向异性烧结机理提供深入的认识，并填补挤压金属AM工艺与金属合金烧结组织之间关系的知识空白。
Metal additive manufacturing (AM) can be achieved by first extruding polymer-based filaments with densely filled metal particles to create the so-called ‘green’ parts and then experiencing debinding and sintering to produce finished metal components. As a critical step, sintering governs the shape dimension, relative density, and resultant strength of final parts. Thus, there is a growing need for research on understanding and quantifying the sintering-induced anisotropic shrinkage. In this work, the underlying behaviors of anisotropic shrinkage during the entire sintering of extrusion-printed stainless steel 316L parts will be understood and quantified through a combination of theoretical study and experimental investigations including three-directional dilatometry, scanning electron microscopy, and X-ray computed tomography. The three-dimensional size evolution of ‘brown’ parts before sintering will be studied through a macroscopic analysis of shrinkage anisotropy factors and microstructure characterizations. Different filling strategies will be integrated with initial pore distribution characterization for anisotropic dimensional change analysis. The heterogeneous pore distribution will be discussed in conjunction with the anisotropic viscous behavior to eventually unveil the shrinkage performance in the course of sintering. The findings of this work will provide insights into the anisotropic sintering mechanisms and fill the knowledge gap of the relations between extrusion-based metal AM process and sintered structures of metal alloys.