Additive manufacturing opens new possibilities for designing light-weight structures using aluminium alloys. The microstructure of two Al alloys and their corrosion resistance in NaCl and natural seawater environments were investigated. The newly designed Al-Mn-Cr-Zr based alloy showed a higher corrosion resistance than reference AlSi10Mg alloy in both environments in as printed and heat-treated conditions. The corrosion initiated in the Al matrix along the precipitates in the alloys where the Volta potential difference was found the highest. The coarser microstructure and precipitate composition of the new Al-alloy led to the formation of a resistant passive film which extended the passivity region of the Al-Mn-Cr-Zr alloy compared to the AlSi10Mg alloy. The effect of heat treatment could be seen in the microstructure as more precipitates were found in between the melt pool boundaries, which affected the corrosion initiation and slightly the pitting resistance. Overall, this study shows that a newly designed Al-alloy for additive manufacturing has a suitable corrosion resistance for applications in marine environments.

Additive manufacturing (AM) allows for optimized part design, reducing weight compared to conventional manufacturing. However, the microstructure, surface state, distribution, and size of internal defects (e.g., porosities) are very closely related to the AM fabrication process and post-treatment operations. All these parameters can have a strong impact on the corrosion and fatigue performance of the final component. Thus, the fatigue-corrosion behavior of the 3D-printed (L-PBF) AlSi10Mg aluminum alloy has been investigated. The influence of load sequence (sequential vs. combined) was explored using Wöhler diagrams. Surface roughness and defects in AM materials were examined, and surface treatment was applied to improve surface quality. The machined specimens showed the highest fatigue properties regardless of load sequence by improving both the roughness and removing the contour layer containing the highest density of defect. The impact of corrosion was more pronounced for as-printed specimens as slightly deeper pits were formed, which lowered the fatigue-corrosion life. As discussed, the corrosion, fatigue and fatigue-corrosion mechanisms were strongly related to the local microstructure and existing defects in the AM sample.

Oxygen electrocatalysts play a key role in renewable and fossil‐free energy production. Bifunctional catalysts active for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) allow use of the same material system for both energy production (ORR) and fuel generation (OER). However, optimizing the performance of bifunctional catalysts requires in depth understanding of the catalyst structure, its surface chemistry in terms of active sites and the underlying catalytic mechanism. Here, the catalytic performance of CoCrFeNi thin films is investigated, synthesized using high‐power impulse magnetron sputtering, as bifunctional oxygen electrocatalysts. The film crystal structure and morphology, and thereby the catalytic performance, can be tuned by the ion acceleration (bias) to the substrate. To further enhance the catalytic activity, anodization is used to electrochemically modify the films, forming a thicker oxide layer enriched in Co and Ni cations which significantly improves the ORR performance. Anodization improves the catalyst stability during OER, with an OER potential of 1.45 V versus the reversible hydrogen electrode (RHE) at 10 mA cm⁻² for more than 24 h. While the corrosion resistance is high both before and after anodization, in terms of catalytic activity the anodized films outperformed the as‐deposited ones. This makes anodized films excellent electrocatalyst candidates in corrosive alkaline environments such as fuel cells and electrolyzers.

Transition metal oxides like Co, Ni, and Mn are promising alternatives to noble metals such as Pt for oxygen electrocatalysis in green energy. Alloying these metals forms multicomponent catalysts with compelling properties. In this study, CoCrFeNi and MnCrFeNi thin films are synthesized using High‐Power Impulse Magnetron Sputtering (HiPIMS) and their catalytic activity for the Oxygen Reduction Reaction (ORR), the Oxygen Evolution Reaction (OER), and corrosion resistance in 1 molar (1 M) potassium hydroxide (KOH) are evaluated. MnCrFeNi films exhibit a fine‐grained single face‐centered cubic (FCC) phase, while CoCrFeNi films have larger grains and multiple phases. ORR on CoCrFeNi follows a 2+1 electron transfer pathway, producing hydroxide radicals, while MnCrFeNi exhibits a 2‐electron pathway, yielding hydrogen peroxide. Anodization reduces the CoCrFeNi overpotential from 0.9 to 0.5 V versus the reversible hydrogen electrode (RHE), comparable to platinum and iridium catalysts (Pt/C, Ir/C). Anodization also shifts CoCrFeNi ORR to a 2‐electron pathway. In situ Raman spectroscopy detects no ORR intermediates, but nickel oxyhydroxide (NiOOH) appears during OER. Substituting Mn for Co increases corrosion resistance by raising the corrosion potential. All films show passive behavior during polarization, demonstrating their potential for corrosion protection and electrocatalysis in green energy applications.