The present work compared the initial stages of corrosion process development on the AM60-AlN metal matrix nanocomposite surface and on AM60, during their exposure for 30 days to simulated acid rain solution (SAR). The AlN nanoparticles were observed as “attached” to those of Mn-rich AlMn intermetallic particles, forming clusters. The introduction of 1.0 wt.% AlN (≈ 80 nm) in the AM60 alloy carried a slight grain refinement and favored the formation of a denser and more protective corrosion layer, suggested by the electrochemical impedance spectroscopy (EIS) values of higher charge transfer resistance (R2) and capacitance, characteristic of the double layer in the presence of corrosion products, and also suggested by Rn (EN) values, compared to those of the AM60 alloy. Thus, the concentration of the released Mg-ions from the composite surface was lower. Due to the increase in time of the SAR solution pH, Al de-alloying may occur, as well as Al(OH)₃ formation, as confirmed by XPS analysis. Due to the presence of Cl-ions in SAR solution, localized corrosion was observed, suggested as fractional Gaussian noise of a stationary and persistent process in time, according to the PSD of the corrosion current fluctuations (EN).

中文翻译：

---

挤压AM60-AlN金属基纳米复合材料和AM60合金在模拟酸雨环境下的腐蚀行为

目前的工作比较了 AM60-AlN 金属基纳米复合材料表面和 AM60 在它们暴露于模拟酸雨溶液 (SAR) 30 天期间腐蚀过程发展的初始阶段。观察到 AlN 纳米颗粒与富含 Mn 的 AlMn 金属间化合物颗粒“附着”在一起，形成簇。在 AM60 合金中引入 1.0 wt.% AlN (≈ 80 nm) 进行了轻微的晶粒细化，并有利于形成更致密和更具保护性的腐蚀层，电化学阻抗谱 (EIS) 值表明具有更高的电荷转移电阻(R2) 和电容，存在腐蚀产物时双电层的特征，以及与 AM60 合金相比的 Rn (EN) 值也表明了这一点。因此，从复合材料表面释放的镁离子浓度较低。由于 SAR 溶液 pH 值的时间增加，可能会发生 Al 脱合金，以及 Al(OH)XPS 分析证实了_{3 的}形成。根据腐蚀电流波动 (EN) 的 PSD，由于 SAR 溶液中存在 Cl 离子，因此观察到局部腐蚀，这表明是固定和持续过程的分数高斯噪声。