Important explorations of the sliding tribological performances of micro/nano-structural interfaces: Cross-shaped microconcave and the nanoNb₂AlC-Sn

Cross-shaped microconcave (CC) cooperated with the Nb₂AlC-Sn (NS) to enhance their collaboration lubrications, thereby extended W alloy-base application scope while retaining their longevity and high accuracy. On sliding tribo-pair systems, tribological behavior of 0.5CC-NS was more excellent than those of another CC-NS. This was mainly attributed to the following reasons: (1) enough NS in the 0.5CC-NS helped a lubrication film formation; high bearing abilities of convex squares accepted massive loads to reduce film damage. (2) Convexity of 13.26 ± 0.52 GPa nano-hardness supported the low-hardness film (1.41 ± 0.19 GPa), made Nb₂AlC and Sn produce nanocrystallines to maintain excellent lubrication. (3) W-alloys, Nb₂AlC and metallic oxides appeared in the film to assist the convex square for an effective resisting to the damages. (4) sliding wear of the films avoided their direct contacts of matching pair, facilitated excellent tribological behaviors of the 0.5CC-NS-W. 0.5CC-NS interfaces were helpful in providing important references for construction of friction interfaces of power-driven gears for arresting enhancements of tribological abilities. © 2022 Elsevier Ltd