论文部分内容阅读
采用电压-时间曲线、全浸腐蚀实验、极化曲线法、X射线衍射法(XRD)、扫描电镜(SEM)、能量色散谱仪(EDS)和X射线光电子能谱法(XPS)等方法研究了AZ91D镁合金在含不同浓度四硼酸钠的阳极化溶液中的阳极氧化行为和膜层的成分、结构.结果表明:在文中给定工艺中,AZ91D镁合金的阳极化过程可分为3个阶段:电火花出现之前的致密层生成阶段;少量小电火花出现的多孔层生成阶段;出现较大电火花的多孔膜层稳定生长阶段.阳极氧化过程中,随着阳极氧化溶液Na2B4O7浓度的升高,出现电火花的时间延长,出现电火花时的电压值升高;膜层厚度增加,膜层上的孔径增大.阳极化膜层中主要含有Mg2+、O2-、Si4+和B3+,主要相结构为MgO、MgSiO3和Mg3B2O6.四硼酸钠浓度对阳极化膜的耐蚀性影响较大,当四硼酸钠浓度为160 g/L时,膜层耐蚀性能最好.
Voltage-time curves, immersion corrosion tests, polarization curves, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) The anodic oxidation behavior and composition and structure of AZ91D magnesium alloy in the anodizing solution containing different concentrations of sodium tetraborate were studied.The results show that in the given process, the anodization of AZ91D magnesium alloy can be divided into three Stage: the dense layer before spark generation stage; a small amount of small sparks occurred during the formation of porous layer; larger sparking porous film stable growth stage.Anodic oxidation process, with the anodic oxidation solution Na2B4O7 concentration High, the spark appears longer, the voltage appears EDM voltage increases; film thickness increases, the film on the pore size increases.Anion film mainly contains Mg2 +, O2-, Si4 + and B3 +, the main phase The structure is MgO, MgSiO3 and Mg3B2O6.The concentration of sodium tetraborate greatly affects the corrosion resistance of the anodized film, and the corrosion resistance of the film is best when the concentration of sodium tetraborate is 160 g / L.