Study of the Radiation Damage Kinetics in NbTiVZr High-Entropy Alloys Irradiated by Heavy Ions

The purpose of this paper was to study the kinetics of accumulation of radiation damage in the near-surface layer of a high-entropy NbTiVZr alloy upon irradiation with heavy Kr15+ ions and fluences of 1010–1015 ion/cm2. According to the data of X-ray diffraction analysis, it was found that irradiation with heavy ions lead to structural changes associated with the accumulation of deformation distortions and stresses. In this case, the nature of deformation distortions was associated with tensile distortions of the crystal lattice and swelling of the near-surface layer. An analysis of the strength properties of the irradiated samples showed that the accumulation of deformation distortions in the near-surface layer lead to a decrease in the resistance to cracking and destruction of the near-surface layer. In this case, the main changes occurred at fluences above 1013 ion/cm2, which are characterized by an excess of the threshold for overlapping defective regions that appear along the trajectory of incident ions. Tribological tests showed that an increase in defective inclusions in the structure of the near-surface layer lead to an increase in friction and a decrease in crack resistance.