Influence of Aluminum Alloy Substrate Temperature on Microstructure and Corrosion Resistance of Cr/Ti Bilayer Coatings

作者：Yuqi Wang, Tao He, Xiangyang Du, Alexey Vereschaka, Catherine Sotova, Yang Ding, Kang Chen, Jian Li, Peiyu He · 发表于：Coatings · 年份：2025 · DOI：10.3390/coatings15080891 · 被引用次数：3 · 研究领域：Metal and Thin Film Mechanics、Corrosion Behavior and Inhibition、High-Temperature Coating Behaviors

Cr/Ti bilayer coatings were deposited on 7050 aluminum alloy via magnetron sputtering at substrate temperatures of room temperature (RT), 150 °C, and 300 °C to investigate temperature effects on microstructure, hardness, and corrosion resistance. All coatings exhibited Cr(110) and Ti(002) phases. Temperature significantly modulated corrosion resistance by altering pore density, grain boundary density, and passivation film composition. Increasing temperature from RT to 150 °C raised corrosion rates primarily due to increased pore density. Further increasing to 300 °C reduced corrosion rates mainly through decreased grain boundary density, while passivation film composition changes altered electrochemical reaction kinetics. Substrate-coating interface defect density primarily influenced hardness with minimal effect on corrosion. Consequently, the RT-deposited coating, despite lower hardness, demonstrated optimal corrosion resistance: polarization resistance (7.17 × 104 Ω·cm2), charge transfer resistance (12,400 Ω·cm2), and corrosion current density (2.47 × 10−7 A/cm2), the latter being two orders of magnitude lower than the substrate.