Interface engineering for the TiC/TiSiCN system: impact of the bilayer number on mechanical and tribological behavior

This article presents a detailed study of the structural, tribo-mechanical properties of an innovate [TiC/TiSiCN] multilayer coating. Structural results showed that the TiSiCN layer has a nanocomposite structure, with nanocrystals (nc-TiSiCN) embedded in an amorphous matrix (a-SiCN), which couple with the crystalline TiC layer, forms a coherent and stable multilayer structure. Mechanical and tribological properties improved substantially with increasing bilayer number; hardness increased from ~ 12 GPa ( n = 1) to ~ 45 GPa ( n = 70), representing a 275% enhancement; the friction coefficient decrease from 0.35 to 0.15 (57% reduction); the wear rate dropped from ~ 8.5 × 10–6 mm 3 /Nm (86% improvement); and the critical adhesive load (Lc2) rose from 28.4 N to 46.3 N (63% increase). These enhancements result from a higher interface density, which restricts dislocation propagation and mobility, increasing resistance to plastic deformation. This system offers optimal protection for engineering devices exposed to extreme friction, temperature and mechanical loads.