Mechanical properties and hydrogen tolerance of particle-reinforced CCA produced by additive manufacturing (MarioCCArt)

在第一个资助期，建立了粉末气体雾化-激光粉床熔融合成颗粒增强高熵合金/成分复杂合金的工艺链(L-PBF)。我们处理了CoCrFeNi(-Al，-Mn)家族的合金，并研究了通过调幅分解、氧化物和氮化物析出进行强化的方法。继续这项工作，我们将集中在后续项目中最成功的这些合金(在L-PBF中没有裂纹形成，单相基质)，以进行更多的应用驱动的研究。将研究两种合金，均为单相A1(FCC)，一种HEA和一种常规合金作为参考。这些合金将由不同化学成分和大小的颗粒增强。将测定这些不同的颗粒尺寸和组成对L-PBF在不同异地和原位工艺路线下的加工性的影响，并将测定所得到的颗粒增强CCA(p-CCA)的力学性能，包括强度、断裂韧性和疲劳强度。此外，氢气和低温对力学性能和显微组织的影响将是该项目的重点。这些分析的目标是开发一种坚固、坚韧、耐疲劳和抗氢的材料。为此，我们将在室温和低温下研究p-CCA和参比合金在气态充氢前后的力学性能和塑性变形机制。为了了解氢对塑性变形和破坏机制的影响，还将使用包括电化学充电电池的纳米压头。研究结果为p-CCA在氢气经济中的应用奠定了基础。

In the first funding period, the process chain for the synthesis of particle-reinforced HEA/CCA (High Entropy Alloys / Compositionally Complex Alloys) via gas atomization of powders and Laser Powder Bed Fusion (L-PBF) was established. We processed alloys in the family CoCrFeNi(-Al,-Mn) and investigated strengthening via spinodal decomposition, oxide and nitride precipitation. Continuing with this work, we will concentrate in the follow-up project on the most successful of these alloys (no crack formation in L-PBF, single-phase matrix) for more application-driven research. Two alloys will be investigated, both single-phase A1 (fcc), one HEA and one conventional alloy for reference. These alloys will be reinforced by particles of various chemical composition and size. The impact of these different particle sizes and compositions on processability in different ex-situ and in-situ process routes in L-PBF will be determined and the mechanical properties of the resulting particle-reinforced CCA (p-CCA) will be determined, including strength, fracture toughness and fatigue strength. Additionally, the influence of hydrogen and of low temperatures on the mechanical properties and on the microstructure will be a focus of the project. The goal of these analyses is to develop a strong, tough, fatigue- and hydrogen-resistant material. To this end, the mechanical properties and the mechanisms of plastic deformation of the p-CCA and reference alloys before and after gaseous hydrogen charging will be investigated at room temperature and at low temperatures. To understand the impact of hydrogen on plastic deformation and failure mechanisms, additionally a nanoindenter including an electrochemical charging cell will be used. The results lay the foundation of the application of p-CCA in the hydrogen economy.