TiAlCrN 涂层 Ti6Al4V 在盐性与酸性介质中的耐久性：钝化膜稳定性的多相分析

Ti 6 Al 4 V components in aerospace and marine applications frequently suffer from coupled mechanical wear and corrosive degradation across severe temperature regimes. While TiAlN-based systems offer good wear resistance, tailoring Cr incorporation to concurrently enhance passivity without triggering microstructural embrittlement remains underexplored. Here, we test the hypothesis that precisely balancing the Cr/Al ratio governs the transition between dense passivation and defective oxide growth. Using plasma-assisted PVD magnetron co-sputtering, we systematically synthesized three distinct compositions- Ti 0.25 Al 0.53 Cr 0.22 N, Ti 0.47 Al 0.37 Cr 0.16 N, and Ti 0.90 Al 0.06 Cr 0.04 N- to decouple the structural, mechanical, and electrochemical roles of each constituent. Micro-hardness tests revealed a 10-15% enhancement across the coatings compared to the bare substrate. Potentiodynamic polarization in 3.5 wt.% NaCl and 3.5 wt.% H 2 SO 4 electrolytes demonstrated that the Cr 0.22 -enriched formulation established a dense, coherent (Al,Cr) 2 O 3 -rich passive barrier, lowering the corrosion current density of the alloy to 607 μA/cm 2 and resisting chloride and sulfate attack. Conversely, the Ti-rich coating formed a poorly stable barrier linked to lattice mismatch and grain boundary porosity. These findings clarify the direct dependence of interfacial barrier stability on Cr partitioning, providing practical composition guidelines for designing robust, wear- and corrosion-resistant coatings.