近共晶铝硅合金阳极氧化工艺研究

发布时间：2018-05-14 11:21

本文选题：铝硅合金 + 阳极氧化　；参考：《沈阳工业大学》2017年硕士论文

【摘要】：本课题对近共晶铝硅合金阳极氧化工艺进行研究,使用脉冲信号电源,对比氧化时间、电流密度、电解液配方等,确定最优的工艺参数。在最佳工艺条件下,以草酸、酒石酸、磺基水杨酸、硫酸高铈作为添加剂,分析添加剂浓度对氧化膜的厚度以及表面形貌的影响,利用扫描电子显微镜分析阳极氧化膜的表面形貌,场发射扫描电子显微镜分析铝、硅、氧等元素在阳极氧化膜上的分布情况,确定添加剂的最佳添加量。利用热震实验,盐雾腐蚀实验,极化曲线分析氧化膜的性能。结果表明:近共晶铝硅合金的阳极氧化膜微孔密度大、孔径小,呈六角蜂窝状结构,随着电解液的浓度、电流密度、氧化时间的增加,经阳极氧化处理的氧化膜变厚,随着脉冲信号电源的参数不同而不同,但阳极氧化过程中,硫酸的酸蚀作用、电流热效应等的影响,氧化膜的厚度会变薄。近共晶铝硅合金阳极氧化最优工艺参数为:电流密度3.2A/dm2,梯形波上升下降时间858.36ns,占空比50%,氧化时间30min,梯形信号脉冲波形频率50Hz。在硫酸电解液中加入柠檬酸、草酸、磺基水杨酸、硫酸高铈等添加剂,可有效阻碍硫酸的侵蚀,增加氧化膜的厚度,改善氧化膜表面质量。通过分析氧化膜的耐腐蚀性,得出添加剂的最佳添加量:草酸6g/L,磺基水杨酸10g/L,柠檬酸25g/L,硫酸高铈0.7g/L。氧化膜耐腐蚀性较好,阳极氧化处理提高了近共晶铝硅合金的耐腐蚀能力。本工艺可操作性强、重复性好,生产效率高,易于推广应用。对电源波形的选用进行了进一步的讨论,对铝合金阳极氧化进行了有益的补充,拓展了铝硅合金应用空间。
[Abstract]:In this paper, the anodic oxidation process of near-eutectic Al-Si alloy is studied. The optimal process parameters are determined by using pulse signal power supply, comparing oxidation time, current density, electrolyte formula, etc. Under the optimum conditions, oxalic acid, tartaric acid, sulfosalicylic acid and cerium sulfate were used as additives to analyze the effect of additive concentration on the thickness and surface morphology of oxide film. The surface morphology of anodic oxide film was analyzed by scanning electron microscope (SEM), and the distribution of aluminum, silicon and oxygen on anodic oxide film was analyzed by field emission scanning electron microscope (SEM), and the optimum additive content was determined. The thermal shock test, salt spray corrosion test and polarization curve were used to analyze the properties of the oxide film. The results show that the anodic oxide film of near-eutectic Al-Si alloy has a large pore density and a small pore size and a hexagonal honeycomb structure. With the increase of electrolyte concentration, current density and oxidation time, the oxide film treated by anodic oxidation becomes thicker. The thickness of oxide film will become thinner due to the influence of acid corrosion of sulfuric acid and current heat effect during anodic oxidation with different parameters of pulse signal power supply. The optimum process parameters for anodic oxidation of near-eutectic Al-Si alloy are as follows: current density 3.2A / dm2, trapezoid wave rise and drop time 858.36ns, duty cycle 50, oxidation time 30min, frequency of trapezoid signal pulse waveform 50Hz. Adding citric acid, oxalic acid, sulfosalicylic acid and cerium sulfate into the electrolyte of sulfuric acid can effectively hinder the erosion of sulfuric acid, increase the thickness of oxide film and improve the surface quality of oxide film. By analyzing the corrosion resistance of the oxide film, the optimum additive was obtained: 6g / L oxalic acid, 10g / L sulfosalicylic acid, 25g / L citric acid, 0.7g / L cerium sulfate. The corrosion resistance of near-eutectic Al-Si alloy was improved by anodizing treatment. The process has strong operability, good repeatability, high production efficiency and easy to be popularized and applied. The selection of power waveform is further discussed, which is helpful to the anodic oxidation of aluminum alloy and expands the application space of Al-Si alloy.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.451

【相似文献】