Characterization of Surface Defects on Pulse-Electrodeposited Nickel Tubes

Electroplated thin-walled tubes were tested in compression. Most cracks were found at defects, i. e. protrusions on the surface of the tubes. The study focusses on the characterization of these defects. Optical microscopy revealed that the defects were already present in the metallization layer and occurred during the metallization process. When electrodepositing a Nickel coating on top, grains grow perpendicular to the surface of the metallization layer creating local orientation changes. Thus, protrusions occur on the surface of the tube where imperfections are located in the metallization layer.