Effect of Annealing on the Microstructure and Structural-Phase State of Nanoscale Multilayer Zr/Nb Coatings after Irradiation with He+ Ions

Radiation degradation is a serious problem affecting the service life of many structural materials used in harsh environments. Modern research is aimed at developing materials with improved mechanical and physical properties, as well as increased resistance to radiation damage. Nanoscale multilayer coatings are one such material. The effect of annealing on the microstructure, defect structure, and mechanical properties of nanoscale multilayer materials consisting of alternating Zr and Nb layers after irradiation with He+ ions was studied. Multilayers Zr/Nb materials were prepared by magnetron sputtering, with the thickness of each layer being 50 nm. Analysis was performed using the following techniques: positron annihilation spectroscopy, X-ray diffraction analysis, and high-resolution transmission electron microscopy. Defects in the structure were investigated layer by layer using a variable energy positron beam and Doppler broadening spectroscopy. Analysis of changes in nanohardness, Young’s modulus, and structural-phase state has shown that the multilayer structure is preserved in Zr/Nb multilayers with a thicknesses of individual layer of 50 nm after irradiation with He+ ions and subsequent annealing in the range from 100 to 300°C.