Universität Kassel, Institute of Materials Engineering, Mönchebergstraße 3, 34125, Kassel, Germany.
Technische Universität Bergakademie Freiberg, Institute of Materials Engineering, Gustav-Zeuner-Straße 5, 09599, Freiberg, Germany.
Sci Rep. 2018 Jan 22;8(1):1298. doi: 10.1038/s41598-018-19376-0.
Electron Beam Melting (EBM) is a powder-bed additive manufacturing technology enabling the production of complex metallic parts with generally good mechanical properties. However, the performance of powder-bed based additively manufactured materials is governed by multiple factors that are difficult to control. Alloys that solidify in cubic crystal structures are usually affected by strong anisotropy due to the formation of columnar grains of preferred orientation. Moreover, processing induced defects and porosity detrimentally influence static and cyclic mechanical properties. The current study presents results on processing of a metastable austenitic CrMnNi steel by EBM. Due to multiple phase transformations induced by intrinsic heat-treatment in the layer-wise EBM process the material develops a fine-grained microstructure almost without a preferred crystallographic grain orientation. The deformation-induced phase transformation yields high damage tolerance and, thus, excellent mechanical properties less sensitive to process-induced inhomogeneities. Various scan strategies were applied to evaluate the width of an appropriate process window in terms of microstructure evolution, porosity and change of chemical composition.
电子束熔化（EBM）是一种粉末床增材制造技术，能够生产具有良好机械性能的复杂金属零件。然而，粉末床增材制造材料的性能受到多种难以控制的因素的影响。通常，凝固为立方晶体结构的合金由于优先取向的柱状晶粒的形成而受到强烈的各向异性的影响。此外，加工引起的缺陷和孔隙度会对静态和循环机械性能产生不利影响。本研究介绍了通过 EBM 加工亚稳奥氏体 CrMnNi 钢的结果。由于在逐层 EBM 工艺中由固有热处理引起的多相转变，材料几乎没有择优取向的晶粒形成了细晶粒微观结构。变形诱导的相变产生了高的损伤容限，从而具有优异的机械性能，对加工引起的不均匀性不敏感。应用了各种扫描策略来评估在微观结构演变、孔隙度和化学成分变化方面适当的工艺窗口的宽度。
