Material mechanisms of Cu/Ni nanolaminate coatings resulting in lifetime extensions of welded joints. (15th April 2022)

• Record Type: Journal Article
• Authors: Brunow, Jakob; Gries, Stella; Krekeler, Tobias; Rutner, Marcus
• Is Part Of: Scripta materialia. Number 212(2022)
• Publication Date: 2022-04-15
• Subjects: Nanostructured materials -- Nanolaminate -- Thin film -- Coating -- Fatigue -- Post-weld treatment -- Welding; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2022.114501
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Metal nanolaminate coatings are introduced as a new approach in post-weld treatment methods. A Cu/Ni nanolaminate coating is electrodeposited from a single Cu/Ni citrate bath onto a butt-welded tension-tension fatigue specimen. The nanolaminate coating consists of a Ni base layer and 160 alternating Cu and Ni layers. The specimen is tested in tension-tension fatigue with a stress range close to the yield strength of the specimen. This first study reveals surprisingly high lifetime extensions of welded joints. The tested specimens are examined using FIB/SEM and TEM. Local roughness measurements are carried out with AFM. This leads to observations on crack behavior of nanostructured Cu/Ni multilayers. The Cu layers show initial multi-crack formation, while the cracks arrest at the Cu/Ni interfaces. The Ni layers bridge those cracks and each Ni layer tears individually. Hypotheses are formed on the fatigue behaviour of Cu/Ni multilayers. Graphical abstract: Image, graphical abstract