铝合金扫描式微弧氧化工艺及性能研究

发布时间：2018-05-20 07:07

本文选题：AlSi7Mg0.3 + 扫描式微弧氧化　；参考：《北京交通大学》2017年硕士论文

【摘要】：铝合金零部件是高铁接触网的核心技术产品,然而在局部或个别区段,阳极氧化和钝化处理的零件表面存在腐蚀和处理层剥落问题,影响接触网服役安全性,给列车运行带来安全隐患。开展铝合金零件的表面防腐耐磨改性技术研究,对保障列车的运行安全具有重要的意义。本文基于微弧氧化技术的原理,结合AlSi7Mg0.3铝合金接触网零部件的服役要求,开展了扫描式微弧氧化的仿真计算、工艺试验和性能测试研究。本文主要研究内容和结论如下:(1)进行前期电流密度、频率和扫描速度的试验,研究这三个重要工艺参数对成膜效率、陶瓷层厚度的影响。基于微弧氧化技术的基本原理,结合前期的工艺试验,选用了高斯热源模型,构建了扫描式微弧氧化有限元仿真分析模型。(2)通过扫描式微弧氧化处理试验与仿真技术相结合,通过正交试验方法,以效率优先的原则,基于扫描时微弧氧化模拟对电流密度(A)、频率(B)和扫描速度(C)三个工艺参进行参数优选,得出A3B1C1、A3B2C1、A3B1C3、A2B3C1这4组较优方案。(3)结合AlSi7Mg0.3铝合金接触网零部件的服役要求,通过拉伸试验及电击穿试验,4号方案A2B3C1(即电流密度8A/dm2、频率250Hz、扫描速度3.6mm/min)处理后得出的性能结果最为良好,故选择4号方案继续研究其不同扫描道次下的腐蚀性能。(4)研究了扫描道次对扫描式微弧氧化陶瓷层厚度、微观形貌及相成分和耐腐蚀性能的影响,采用极化曲线、酸性盐溶液周浸腐蚀试验方法评价了微弧氧化陶瓷层的耐腐蚀性能。结合铝合金接触网零部件的实际服役,扫描道次为3次时陶瓷层的综合性能较优。
[Abstract]:Aluminum alloy components are the core technical products of high iron catenary. However, the surface of the parts treated by anodizing and passivation is corroded and spalling, which affects the safety of catenary service. Bring safety hidden danger to train operation. It is of great significance to study the surface anticorrosion and wear resistance modification technology of aluminum alloy parts to ensure the safety of train operation. Based on the principle of micro-arc oxidation and the service requirement of AlSi7Mg0.3 aluminum alloy catenary parts, the simulation calculation, process test and performance test of scanning micro-arc oxidation are carried out in this paper. The main contents and conclusions of this paper are as follows: (1) the experiments of current density, frequency and scanning speed are carried out, and the effects of these three important technological parameters on the film forming efficiency and ceramic layer thickness are studied. Based on the basic principle of micro-arc oxidation technology, combined with the previous process test, the Gao Si heat source model was selected, and the finite element simulation analysis model of scanning micro-arc oxidation was constructed, and the scanning micro-arc oxidation treatment test was combined with the simulation technology. Based on the principle of efficiency priority, the parameters of current density, frequency B) and scanning speed C) were optimized by orthogonal experiment based on the simulation of micro-arc oxidation during scanning. A3B1C1C1A3B2C1A3B1C1A3B1C3A2B3C1) combined with the service requirements of AlSi7Mg0.3 aluminum alloy catenary parts, through tensile test and electric breakdown test, the treatment of A2B3C1A2B3C1 (current density 8A / dm2, frequency 250Hz, scanning speed 3.6mm / min) shows the best performance results. Therefore, the influence of scanning pass on the thickness, micromorphology, phase composition and corrosion resistance of scanning micro-arc oxidation ceramic layer was studied by means of polarization curve. The corrosion resistance of micro-arc oxidation ceramic coatings was evaluated by cyclic immersion corrosion test of acid salt solution. Combined with the actual service of aluminum alloy catenary parts, the comprehensive properties of ceramic coating are better when the scanning pass is 3 times.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

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