纳米SiC增强铝合金表面阳极氧化膜的组织与性能

Structure and Performance of Anode Oxide Films on the Surface of Aluminum Alloy Reinforced by Nano-SiC

以硫酸、草酸、氨基磺酸为基础电解液,分别添加3,8,12,15 g/L的纳米SiC颗粒,利用直流氧化电源在优化的复合共沉积工艺参数下,在2024铝合金表面制备纳米SiC增强的硬质阳极氧化膜.结果表明:纳米SiC颗粒弥散分布在阳极氧化膜中,形成了纳米颗粒增强的硬质Al2O3氧化膜组织结构;随着纳米SiC添加量的增加,膜的厚度由没有添加纳米SiC颗粒的42μm增加到了48μm;当SiC的添加量为12 g/L时,氧化膜的硬度最高而磨耗最低,硬度由没有添加纳米颗粒样品的400 HV左右提高到了440 HV,磨损量由25 mg降到8 mg;纳米SiC在阳极氧化过程中,通过机械夹杂、吸附作用等形式进入膜层和孔隙,从而改变了膜层的组织结构,提高了氧化膜的硬度,使氧化膜的耐磨性能提高.

Using H2SO4,H2C2O4 and C7H6O6S·2H2O as the basic electrolyte containing nano-SiC particles of 3,8,12 and 15 g/L,respectively,anodic oxide Al2O3 films with nano-SiC particles were prepared on the surface of a 2024 aluminum alloy by using optimal operating parameters.The results showed that the hard anodic oxide Al2O3 films reinforced by nano-SiC particles were formed.With increasing the content of nano-SiC particles in the electrolyte,the thickness of the composite oxide films increases from 42 μm without the nano-SiC additions to 48 μm,and the hardness increases first and then decreases. When the nano-SiC addition was 12 g/L,the composite oxide film exhibits the highest hardness 440 HV and the minimum wear loss 8mg.The hardness of the composite oxide film increases from 400 HV without nano-SiC additions to 440 HV, and the wear loss decreases from 25 mg to 8 mg.Nano-SiC particles enter in pores of anodic films during mechanical mixing and adsorbing in the processes of anodic oxidation,and then the microstructures of films were changed,the hardness and the wear resistance of the films are also improved.