等离子体电解渗碳对AZ91D镁合金耐蚀性的影响

Influence of Plasma Electrolytic Carburizing on Corrosion Resistance of AZ91D Magnesium Alloy

将AZ91D镁合金在甘油碳酸钠电解液中进行等离子体电解渗透处理。利用SEM,XRD分析试样的表面形貌及相组成,用极化曲线及点滴实验分析其耐蚀性。结果表明:经过处理后的试样形成不均匀的表面形貌,并存在含碳的新物相;自腐蚀电流密度明显减小,自腐蚀电位正移;点滴实验的变色时间延长。渗碳层在一定程度上提高了基体的耐蚀性。

The AZ91D magnesium alloy was treated by plasma electrolytic penetration in glycerin sodium carbonate electrolyte.The surface morphology and phase composition of the prepared sample were analyzed by SEM and XRD respectively.Additionally,polarization curve and dropping experiment were used to analyse its corrosion resistance.The results indicate that the treated sample forms a heterogeneous surface morphology and possesses a new phase containing carbon; its self-corrosion current density decreases sharply and its self-corrosion potential shifts positively; the discoloration time of the dropping experiment is extended.It is shown that carburized layer can improve the corrosion resistance of the matrix to some extent.