Gabilondo Maitane, Cearsolo Xabier, Arrue Mario, Castro Francisco
Department of Additive Manufacturing, IMH Campus, Azkue Auzoa, 1, 20870 Elgoibar, Spain.
Independent Consultant, Gorraiz, 31620 Valle de Egüés, Spain.
Materials (Basel). 2022 Feb 4;15(3):1183. doi: 10.3390/ma15031183.
Bound Metal Deposition (BMD) is an alternative to the most common additive manufacturing (AM) technology for metal parts, Powder Bed Fusion (PBF), since the equipment used is more affordable and there are no risks due to exposure to loose powder and lasers or beams. However, the mechanical properties of parts manufactured by BMD are generally lower than those of PBF, making it necessary to study the process parameters to improve their performance. The aim of this work was to analyse the effect of different process parameters on the mechanical properties of 316L parts manufactured by BMD based on a set of specially designed experiments. The methodology followed in this research was thus based on the manufacturing of a series of samples with variations of the build orientation, infill pattern and chamber temperature followed by subsequent characterization and analysis. The microstructural analysis showed that voids were formed as a consequence of the air gaps generated between rasters during printing. It was observed that the characteristics of these macropores had a significant effect on the mechanical properties. The location, distribution and shape of these macropores depended on the alignment of rasters in each of the conditions, which varied with build orientation and infill pattern. Regarding the build orientation, horizontal parts exhibited lower porosity and considerably higher ultimate tensile strengths (UTS), approximately 160 MPa higher, than vertical samples. With respect to the infill pattern, horizontal parts with a concentric infill pattern showed triangular voids and a total porosity higher than 5%. However, samples with line infill patterns presented elongated macropores and a total porosity lower than 5%, properties that resulted in an improvement in UTS of 20 MPa, approximately. Overall, the results presented here offer a better comprehension of the effect of the BMD process parameters on mechanical properties and serve as a guideline for future work.
与用于金属零件的最常见增材制造（AM）技术——粉末床熔融（PBF）不同，粘结金属沉积（BMD）是一种替代技术，因为所使用的设备价格更为亲民，而且不存在因暴露于松散粉末以及激光或光束而带来的风险。然而，通过BMD制造的零件的机械性能通常低于PBF制造的零件，因此有必要研究工艺参数以提高其性能。这项工作的目的是基于一组专门设计的实验，分析不同工艺参数对通过BMD制造的316L零件机械性能的影响。因此，本研究采用的方法是制造一系列样品，改变其构建方向、填充图案和腔室温度，随后进行表征和分析。微观结构分析表明，孔隙是在打印过程中光栅之间产生的气隙导致形成的。据观察，这些大孔的特征对机械性能有显著影响。这些大孔的位置、分布和形状取决于每种条件下光栅的排列方式，而光栅排列方式会随着构建方向和填充图案的变化而变化。关于构建方向，水平零件的孔隙率较低，极限抗拉强度（UTS）明显更高，比垂直样品高出约160MPa。关于填充图案，具有同心填充图案的水平零件呈现出三角形孔隙，总孔隙率高于5%。然而，具有线性填充图案的样品呈现出细长的大孔，总孔隙率低于5%，这些特性使得UTS提高了约20MPa。总体而言，此处呈现的结果有助于更好地理解BMD工艺参数对机械性能的影响，并为未来的工作提供指导。
