Chromium as a microstructural architect in graphite-like carbon coatings for precision glass molding

The application of graphite-like carbon (GLC) coatings in precision glass molding (PGM) is limited by their insufficient high-temperature anti-adhesion performance and premature failure caused by structural disorder and brittleness. Moving beyond conventional doping strategies, this study employs controlled chromium (Cr) doping to tailor the sp2 carbon nanostructure of GLC coatings at a fundamental level. Cr acts as a catalytic architect, inducing a deliberate transformation from sp3-to sp2-bonded carbon and promoting the formation of a dense, continuous network of sp2-hybridized nanoclusters. This Cr-engineered microstructure provides the optimized coating with a favorable combination of properties, including enhanced fracture resistance (H/E = 0.056, H3/E2 = 0.03), low wear rate of 3.32 × 10−6 mm3 N−1 m−1, and reliable anti-adhesion performance under practical PGM conditions, outperforming both undoped and excessively doped coatings. These findings establish a clear microstructure-performance relationship and offer a design principle for developing high-performance carbon-based coatings, opening up new routes for demanding thermomechanical applications.