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目的：提高铝合金接触网零部件表面耐磨损性能,以增加其在大风沙地区的使用寿命。方法对接触网零件切割进行试样制备。在硅酸盐体系电解液中,采用20 kW直流脉冲微弧氧化设备对试样表面进行微弧氧化处理,电解液为硅酸盐,氧化时间为30 min。同时制备阳极氧化处理的平行试样。通过硬度测试、摩擦磨损试验以及扫描电子显微镜( SEM)测试,分别评价两种表面处理方式的表面硬度、耐磨性能,利用中性盐雾试验来评价其耐腐蚀性能,并通过扫描电子显微镜来观察两种膜层的差异。结果通过对铝合金接触网进行阳极氧化和微弧氧化处理能明显提高表面耐磨性。阳极氧化膜层硬度为350.3 HV,微弧氧化膜层硬度约为阳极氧化膜硬度的4倍,达到1510.8HV。经过HT-600高温摩擦磨损试验机30 min的磨损试验,铝合金基体质量损失2 mg,阳极氧化膜质量损失0.8 mg,而微弧氧化膜的质量损失只有0.15 mg左右,且微弧氧化膜层表现出了更好的耐腐蚀性能。结论微弧氧化膜层能表现出更加优异的耐磨及耐腐蚀性能,因此微弧氧化更适合大风沙地区铝合金零件的表面处理。

ABSTRACT:Objective To improve the abrasion resistance of part surface of aluminum alloy catenary, in order to enhance its service life in wind drift sand regions. Methods The incised parts of aluminum alloy catenary were adopted to prepare samples. Mi-cro-arc oxidation coatings on the surface of samples were formed in silicate-based electrolyte under 20 kW DC pulse for 30 minutes. At the same time, anodic oxidation samples were generated for a contrastive analysis. The surface hardness and abrasion resistance of the coatings were evaluated through hardness test, abrasive wear experiment and SEM test, and neutral salt spray test was used to evaluate their corrosion resistance. The difference of the two coatings was observed by SEM. Results The abrasion resistance of part surface of aluminum alloy catenary was obvisously improved by both anodic oxidation and micro-arc oxidation. The anodic oxi-dation film was 350. 3HV in hardness, while the hardness of MAO film was 1510. 8HV, four times higher than that of the anodic oxidation film. After a 30 minutes′test in HT-600 high temperature wear and abrasion test machine, the MAO lost its weight by on-ly 0. 15 mg, comparing to 0. 8 mg of anodic oxidation film and 2 mg of aluminum alloy substrate. Besides, the MAO films showed a better corrosion resistance. Conclusion In the comparative test between micro arc oxidation and anodic aluminum oxidation coa-tings, the micro-arc oxidation coatings showed better abrasion resistance and corrosion resistance. Therefore, micro arc oxidation was more suitable for treatment of aluminum alloy parts in the windy and dusty area.