Study of Surface Wear of Punches and Molds for Optimization of Nuclear Fuel Production

This paper presents the results of a comprehensive study of the wear processes of press tools used in the molding of uranium dioxide (UO2) nuclear fuel pellets. Particular attention is paid to the analysis of the influence of operating conditions on changes in microstructure, geometry and physical and mechanical properties of working surfaces of molds and punches. The studies using scanning electron microscopy (SEM), X-ray fluorescence (XRF) and X-ray phase analysis (XRD) methods, as well as evaluation of microhardness and roughness, allowed to identify the dominant failure mechanisms—abrasive and adhesive wear, microcrack formation and local degradation of coatings. The results of the experiments confirmed the presence of progressive changes on the working surfaces of the tool, affecting the formation of defects of fuel pellets and reducing the service life of the press equipment. This work allows us to not only better understand the wear patterns in the batch production of nuclear fuel, but also to formulate practical recommendations to increase tool life by optimizing pressing modes and using wear-resistant coatings.