为解决7075铝合金在海洋环境中因表面硬度低、耐磨耐蚀性差而导致的早期失效问题，本研究采用磁控溅射预镀Ti膜与等离子体渗氮相结合的复合表面技术，在铝合金表面构建了Ti-N化合物/Ti-Al金属间化合物/铝基体的梯度结构涂层。通过系统调控渗氮温度（460~520 ℃），重点揭示了涂层结构演变与性能强化机制。结果表明，随渗氮温度升高，Ti与N互扩散加剧，促使低氮固溶体TiN0.3向富氮相转变，并在520 ℃时形成TiN纳米晶弥散强化相；同时，Ti-Al互扩散反应显著增强，形成厚度达26.49 μm的梯度界面层，有效缓解了涂层与基体的力学失配。力学性能分析显示，N520样品表面硬度最高（13.44 GPa），其高H/E与H3/E2值表明优异的抗塑性变形与裂纹扩展能力。磨损实验中，N520梯度结构涂层在5N载荷下表现出极低磨损率（9.24×10-16 m3/(N·m)），但在大载荷下，网格状微观裂纹成为应力集中源，导致涂层局部剥落。腐蚀磨损行为受电解液渗入微裂纹引发的电偶效应主导，加速界面腐蚀与涂层失效，而磨球产生的FeOOH转移膜部分抑制了氧扩散。本研究从微观结构演化、力学响应与多场耦合损伤角度，阐明了梯度涂层的强化机制与腐蚀磨损协同失效行为，为高性能铝合金表面防护设计提供了理论依据。

Aluminum alloys are widely used in marine engineering applications. However, due to their inherent properties, Al alloys commonly face severe challenges of corrosion and wear failure. Current single-surface strengthening techniques for aluminum alloys, like plasma implantation, micro-arc oxidation and physical vapor deposition, still exhibit numerous limitations and considerable difficulties in process design. This thesis employs a combined magnetron sputtering and ion nitriding technique to fabricate a gradient-structured coating on 7075Al alloy, which consisted of Ti-N compounds/Ti-Al intermetallic compounds/aluminum substrate. By changing the nitriding temperature (460 °C to 520 °C), the comprehensive properties of the coating are enhanced. The experimental results show that the titanium nitride gradient coating exhibits well-defined interfacial boundaries and excellent adhesion. The primary phases are TiN0.3 and Al2Ti, and the relative content of TiN0.3 increased with the rising nitriding temperature. HRTEM analysis reveals the formation of TiN nanocrystalline particles on the surface of the N520 sample. The mechanical properties of the titanium nitrided coating also improved with increasing nitriding temperature. The N520 sample exhibited the highest hardness and lowest wear rate, with a wear rate of 9.24 × 10-16 m3/N·m at a load of 5 N. Under heavy loads, increased shear forces caused the surface coating of the N490 sample to fracture into discrete micro-zones due to the presence of net-like microcracks. Anisotropic slippage occurred during wear, leading to mutual collision and compression that resulted in complete coating spalling and failure. The N520 sample exhibiting higher H/E and H3/E2 values did not experience wear failure. However, due to the presence of net-like microcrack structure on the surface of the titanium nitrided coating, the electrolyte can penetrate through the nitriding layer into the intermetallic compound (IMC) layer, even reach the coating/substrate interface during the initial stages of corrosion, forming a corrosion cell that significantly accelerates the corrosion rate finally. The corrosion wear rate of the samples was higher than the dry friction wear rate.