Material mechanisms of Cu/Ni nanolaminate coatings resulting in lifetime extensions of welded joints

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