Assessment of the Archard Hardness–Wear Relationship in Swift Xe-Ion-Irradiated Nickel-Based Superalloys

The study evaluates whether irradiation-induced changes in tribological wear of nickel-based superalloys can be explained by corresponding hardness changes using a normalized Archard approach. Previously obtained microhardness and wear data for Inconel 718 and Nimonic 90 irradiated with 160 MeV Xe²⁴⁺ ions at fluences of 1.0×10;¹⁴, 2.5 × 10¹⁴, and 5.0×10¹⁴ ions/cm² were reprocessed. Relative hardness R_H, relative wear-track area R_A, and the relative Archard coefficient k_r were calculated for hardness measured at 1, 5, and 10 gf. For Inconel 718, R_H reached 1.87, R_A decreased to 0.40, and k_r ranged from 0.61 to 1.86. For Nimonic 90, R_H decreased to 0.53, R_A increased to 30.69, and k_r ranged from 4.04 to 31.19. The dependence of k_r on indentation load further indicates that a single hardness value may be insufficient for Archard-type interpretation of irradiation-modified surface layers. The results show that wear changes cannot be explained by hardness scaling alone and must be considered together with depth-dependent mechanical response and changes in tribological contact conditions.