Magnesium-based materials are promising lightweight structural materials due to their excellent properties. However, their extensive application has been severely limited due to their high corrosion susceptibility. The inadequate corrosion resistance of Mg is mainly attributed to the porous and unprotective native surface film formed on Mg in aggressive environments. Here, we demonstrated a new environment-friendly route for the growth of a continuous nesquehonite (MgCO₃·3H₂O) protective film on the surface of pure Mg metal at a relatively low temperature via an in situ reaction of the Mg surface with gaseous phase CO₂ in humid environments. The protective film consists solely of highly crystalline MgCO₃·3H₂O that is compact and has an umbrella-like structure. Electrochemical tests showed that compared to the untreated Mg substrate, the protective film can effectively improve the corrosion resistance of the substrate by nearly two orders of magnitude. Additionally, a possible formation mechanism of the nesquehonite film on the pure Mg was proposed and the effect of the carbonation time on the film was investigated. This environmentally-friendly surface treatment method is promising for use in the protection of magnesium-based materials.

中文翻译：

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一种在纯镁上原位形成高耐蚀三水锰矿薄膜的环保新途径

镁基材料因其优异的性能而成为有前途的轻质结构材料。然而，由于其高腐蚀敏感性，其广泛应用受到了严重限制。镁的耐腐蚀性能不足主要是由于在侵蚀性环境中镁上形成了多孔且无保护性的原生表面膜。在这里，我们展示了一种新的环境友好路线，通过镁表面与气态的原位反应，在相对较低的温度下在纯镁金属表面生长连续的三水锰矿（MgCO ₃ ·3H ₂ O）保护膜。潮湿环境中的CO ₂相。该保护膜仅由高度结晶的MgCO ₃ ·3H ₂ O组成，其致密且具有伞状结构。电化学测试表明，与未处理的镁基体相比，保护膜能有效提高基体的耐腐蚀性能近两个数量级。此外，提出了纯镁上三水菱镁矿薄膜的可能形成机制，并研究了碳化时间对薄膜的影响。这种环保的表面处理方法有望用于镁基材料的保护。