(哈尔滨工业大学 先进焊接与连接国家重点实验室，哈尔滨 150001)
摘 要: 采用恒压模式于硅酸盐体系中在V型内腔试件表面制备微弧氧化膜，研究V型角度对微弧氧化膜不均匀性的影响。采用数字式测厚仪、扫描电子显微镜和X射线衍射仪研究其微观结构，利用电化学分析仪进行耐蚀性的评定。结果表明：V型试件内表面的相组成无明显差别，均为γ-Al2O3，但其内表面的膜层厚度分布不同，且随着V型试件张角的增大，其内表面膜层厚度差值逐渐减小，由3.1 μm减小到0.4~0.9 μm，不均匀程度减小。此外，V型试件内表面边缘氧化膜层的耐蚀性较优，而靠近折弯处氧化膜层的耐蚀性较差，这是由于试件内表面受不同程度电力线屏蔽造成的。增大脉冲宽度对膜层不均匀性影响很小，但增加氧化处理时间后，试件内表面不均匀程度增大。
关键字: 纯铝；V型槽；微弧氧化；不均匀性
（State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China）
Abstract:The micro-arc oxidation (MAO) coatings were formed on the V-shaped aluminum cavity in the silicate electrolyte with constant voltage mode. The effect of the V-shaped angle on the inhomogeneity of MAO coatings was investigated. The microstructure and surface morphology were investigated using the digital coating thickness gauge, SEM and XRD, and the corrosion resistance was assessed by the electrochemistry analyzer. The results show that the phase compositions are almost γ-Al2O3, which does not demonstrate obvious difference for the inner surface of V-shaped specimen. In contrast, the thickness of the coatings on the inner surface varies substantially at different sites. With the increase of the angle of the V-shaped specimen, the thickness difference becomes slight, decreasing from 3.1 μm to 0.4−0.9 μm. A better corrosion resistance is observed near the edge of the samples and a worse corrosion resistance appears near the bent position of the samples. It may be attributed to different shielding effects of the electric field in the V-shaped cavity. The effect on the inhomogeneity by increased pulse duration is small, but with the increase of oxidation time, the inhomogeneity degree enlarges.
Key words: pure aluminum; V-shaped cavity; micro-arc oxidation; inhomogeneity
