Advanced Complementary Techniques For The Investigation Of Pure Copper Plates Friction Stir Welding

This paper aim is to present a series of advanced complementary techniques for the investigation of microstructure and mechanical behavior of pure copper plates joined by Friction Stir Welding (FSW). The most critical application for friction stir welding of copper, within the nuclear field, is the corrosion barrier canister for spent nuclear fuel. The testing samples consisted of 3 mm thick plates of Cu-DHP (phosphorus - deoxidized copper) which have been welded by FSW. Nondestructive testing using penetrating radiation (X-ray radiography) provided information about the quality of the inner welding. Optical microscopy investigations and Vickers microhardness tests displayed differences in FSW area and nearby affected zone comparing to bulk material. X-ray Diffraction (XRD) was used for residual stress analysis. Tensile testing assisted by Digital Image Correlation (DIC) technique provided information about strain field evolution while Scanning Electron Microscopy (SEM) was used for highlighting the fracture zones. (author).