Reiberg Marius, Hitzler Leonhard, Apfelbacher Lukas, Schanz Jochen, Kolb David, Riegel Harald, Werner Ewald
Institute of Materials Science, Technical University Munich, 85748 Garching, Germany.
Laser Application Center (LAZ), Aalen University, 73430 Aalen, Germany.
Materials (Basel). 2022 Nov 8;15(22):7892. doi: 10.3390/ma15227892.
High entropy alloys (HEAs) and their closely related variants, called multi-principal element alloys (MPEAs), are the topic of a rather new area of research, and so far, the gathered knowledge is incomplete. This is especially true when it comes to material libraries, as the fabrication of HEA and MPEA samples with a wide variation in chemical compositions is challenging in itself. Additive manufacturing technologies are, to date, seen as possibly the best option to quickly fabricate HEA and MPEA samples, offering both the melting metallurgical and solid-state sintering approach. Within this study, CrFeNiTi MPEA samples were fabricated via laser powder-bed fusion (PBF-LB) and solid-state sintering of mechanically alloyed powder feedstock. The main emphasis is on the PBF-LB process, while solid-state sintering serves as benchmark. Within a volumetric energy density (VED) window of 50 J/mm to 83 J/mm, dense samples with large defect-free sections and an average micro-hardness of 965 HV0.1 were fabricated. Clear correlations between the local chemical alloy composition and the related micro-hardness were recorded, with the main factor being the evaporation of titanium at higher VED settings through a reduction in the C14_Laves phase fraction.
高熵合金（HEAs）及其密切相关的变体，即所谓的多主元合金（MPEAs），是一个相当新的研究领域的主题，到目前为止，所积累的知识并不完整。在材料库方面尤其如此，因为制造具有广泛化学成分变化的高熵合金和多主元合金样品本身就具有挑战性。迄今为止，增材制造技术被视为快速制造高熵合金和多主元合金样品的最佳选择，它提供了熔融合金冶金和固态烧结方法。在本研究中，通过激光粉末床熔融（PBF-LB）和机械合金化粉末原料的固态烧结制备了CrFeNiTi多主元合金样品。主要重点是PBF-LB工艺，而固态烧结作为基准。在50 J/mm至83 J/mm的体积能量密度（VED）窗口内，制备出了具有大的无缺陷截面且平均显微硬度为965 HV0.1的致密样品。记录了局部化学合金成分与相关显微硬度之间的明确相关性，主要因素是在较高VED设置下钛的蒸发导致C14_Laves相分数降低。
