【摘要】 利用XRD、SEM、EDX等方法 ,研究了纯镁与AZ91D镁合金在六氟铝酸钠 (Na3 AlF6)、氢氧化钾 (KOH)、六偏磷酸钠((NaPO3 ) 6)和三乙醇胺四元组分电解液中双脉冲微弧氧化膜层的形成、膜层形貌和成分结构。研究发现 ,负脉冲的载入极大地影响了微放电的数量与外观 ;氧化物层表面可以观察到 3类微孔 ,它们的尺寸范围分别是 0 .5～ 1μm、1～ 2 μm和 4～ 7μm ,同时在较大微孔的周围发现有微裂纹存在 ;基体与氧化物交界处存在氟化物富集区 ,纯镁和AZ91D合金表面膜层的氟化物富集区的尺寸范围分别是 4～ 6μm和 3～ 5 μm。更多还原

【Abstract】 The surface morphology and chemical composition of the formed oxide films on pure magnesium and AZ91D alloy in aqueous electrolytes containing sodium hexafluorinealuminate (Na 3AlF 6),potassium hydroxide (KOH),sodium hexametahposphate (NaPO 3) 6,and triethanolamine with bipolar microarc oxidation were investigated by XRD,SEM,EDX.The input of the negative pulse has great effects on the amount and appearance of the microdischarge.Three types of micro-holes,size range in 0.5～1 μm,1～2 μm and 4～7 μm respectively,can be observed on the surface of the oxidized layer,meanwhile micro-cracks appear around a larger micro-hole.There exists a remarkable fluoride-enriched zone with about 4～6 μm for the pure magnesium and 3～5 μm for AZ91D alloy at the coating/substrate interface.更多还原