镁合金表面冷喷涂层耐蚀性研究

Investigation on Corrosion Resistance of Cold Spraying Coating on Mg Alloy Surface

采用冷喷涂方法,将锌铝合金粉末喷涂到镁合金的表面。采用SEM和EDX等试验方法观察冷喷涂层与基体镁合金界面的微观组织。结果表明:基体与涂层之间结合良好,未发生扩散,无分层、空隙等缺陷。硬度试验结果表明,冷喷涂后,镁合金表面硬度为基体的3倍,提高了镁合金基体的耐磨性。盐雾腐蚀试验结果表明,冷喷涂后镁合金经48 h盐雾腐蚀后,仍无腐蚀倾向,冷喷涂层能够很好保护基体镁合金不受腐蚀。

Zn-Al alloy powder was sprayed on Mg alloy surface by cold spraying method. SEM and EDX were used to investigate the microstructures of the interfaces between the cold spraying layer and the Mg alloy matrix. The results show that the combination of the matrix and the coating is good and no diffusion, delamination, interstice or other defects are found. The microhardness tests show that the surface hardness of the cold spraying material is three times of the matrix. The ability of abrasion resistance for the material is obviously enhanced. The results of salt mist corrosion tests show that after 48 h of experimental time, the cold spraying material has no corrosion tendency. As a result, the cold spraying coating can well protect the Mg matrix from corrosion.