發(fā)布時(shí)間：2018-12-14 03:52

【摘要】：以Na2Mo O4為主鹽,與氧化劑H2O2、成膜促進(jìn)劑NaF和Na2Si O3一起組成化學(xué)轉(zhuǎn)化液,在AZ31鎂合金表面制備鉬酸鹽轉(zhuǎn)化膜,利用掃描電鏡和X線光電子能譜儀分析轉(zhuǎn)化膜的形貌和組成,通過電化學(xué)阻抗測試研究轉(zhuǎn)化膜在3.5%Na Cl溶液中的腐蝕行為,并討論成膜機(jī)理,研究轉(zhuǎn)化液中Na2Mo O4濃度與p H以及成膜溫度和時(shí)間對(duì)薄膜結(jié)構(gòu)與耐腐蝕性能的影響。結(jié)果表明:轉(zhuǎn)化液的優(yōu)化組成為0.2 mol/L Na2Mo O4+0.12 mol/L NaF+0.014mol/L Na2Si O3+0.012 mol/L H2O2;優(yōu)化工藝條件為p H=5,溫度60℃,轉(zhuǎn)化時(shí)間30 min;轉(zhuǎn)化膜為黃棕色,主要由Mg Mo O4,Mg F2,Mo O2,Mo O3和Mg Si O3組成,轉(zhuǎn)化膜宏觀上完整均勻,存在網(wǎng)狀微裂紋;鉬酸鹽轉(zhuǎn)化膜能有效提高AZ31鎂合金的耐腐蝕性能,對(duì)基體合金有一定的保護(hù)作用。
[Abstract]:The molybdate conversion film was prepared on the surface of AZ31 magnesium alloy by using Na2Mo O 4 as main salt, oxidant H 2O 2, film forming accelerator NaF and Na2Si O 3. The morphology and composition of the conversion film were analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy. The corrosion behavior of the conversion film in 3.5%Na Cl solution was studied by electrochemical impedance measurement, and the mechanism of film formation was discussed. The effects of Na2Mo O 4 concentration and pH in the conversion solution, film forming temperature and time on the structure and corrosion resistance of the film were studied. The results show that the optimum composition of the conversion solution is 0.2 mol/L Na2Mo O 4 0.12 mol/L NaF 0.014mol/L Na2Si O 3 0.012 mol/L H 2O 2, the optimum process conditions are: pH 5, temperature 60 鈩，

本文編號(hào)：2377868