Pathways toward the Use of Non-Destructive Micromagnetic Analysis for Porosity Assessment and Process Parameter Optimization in Additive Manufacturing of 42CrMo4 (AISI 4140) [Dataset]

Laser-based powder bed fusion of metals (PBF-LB/M) is a widely applied additive manufacturing technique. Thus, PBF-LB/M represents a potential candidate for the processing of quenched and tempered (Q&T) steels such as 42CrMo4 (AISI 4140), as these steels are often considered as the material of choice for complex components, e.g., in the toolmaking industry. However, due to the presence of process-induced defects, achieving a high quality of the resulting parts remains challenging in PBF-LB/M. Therefore, an extensive quality inspection, e.g., using process monitoring systems or downstream by destructive or non-destructive testing (NDT) methods, is essential. Since conventionally used downstream methods, e.g., X-ray computed tomography, are time-consuming and cost-intensive, micromagnetic NDT measurements represent an alternative for ferromagnetic materials such as 42CrMo4. A system combining several micromagnetic NDT measurement methods is the micromagnetic multiparametric microstructure and stress analyzer (3MA), developed by the Fraunhofer Institute for Nondestructive Testing IZFP (Saarbrücken, Germany). The results of 3MA measurements have already been correlated with various material properties, however, the use of the 3MA technology for the quality inspection of AM components was missing. To investigate the potential of the 3MA technology in this context, potential relations between micromagnetic properties and the porosity of AM components was investigated in the study described in https://doi.org/10.3390/ma17050971. In the study, 42CrMo4 samples were manufactured by PBF-LB/M with different process parameters. The samples were analyzed using a 3MA system and porosity values determined by image analysis of micrographs. Using multiple regression modeling, relations between the PBF-LB/M process parameters and six selected micromagnetic variables and relations between the process parameters and the porosity were assessed. The results reveal first insights into the use of micromagnetic NDT measurements for porosity assessment and process parameter optimization in PBF-LB/M-processed components.

金属激光粉末床熔融（PBF-LB/M）是一种应用广泛的增材制造技术。因此，PBF-LB/M是加工调质钢（Q&T）（如42CrMo4钢，AISI 4140）的潜在候选技术，这类钢常被视为复杂部件的首选材料，例如在模具制造行业中。然而，由于工艺诱导缺陷的存在，在PBF-LB/M中获得高质量成品部件仍具挑战性。因此，全面的质量检测至关重要，例如使用工艺监测系统，或在下游采用破坏性或非破坏性检测（NDT）方法。由于传统下游方法（如X射线计算机断层扫描）耗时且成本高昂，微磁NDT检测为42CrMo4等铁磁材料提供了替代方案。整合多种微磁NDT检测方法的系统是微磁多参数组织与应力分析仪（3MA），由德国萨尔布吕肯弗劳恩霍夫无损检测研究所IZFP开发。3MA测量结果已与多种材料性能相关联，但将3MA技术应用于增材制造（AM）部件质量检测的研究尚属空白。为探究此背景下3MA技术的潜力，https://doi.org/10.3390/ma17050971所述研究考察了微磁性能与AM部件孔隙率的潜在关系。该研究采用不同工艺参数通过PBF-LB/M制备42CrMo4钢试样，通过3MA系统分析试样，并通过显微图像的图像分析确定孔隙率值。利用多元回归建模，评估了PBF-LB/M工艺参数与6个选定微磁变量的关系，以及工艺参数与孔隙率的关系。研究结果首次揭示了微磁NDT检测在PBF-LB/M加工部件孔隙率评估及工艺参数优化中的应用前景。