亚快速凝固Cu-15Al-4Fe合金组织及耐蚀性研究

Microstructure and Corrosion Performance of Sub-rapidly Solidified High Aluminum Bronze Cu-15Al-4Fe Alloy

通过铜模吸铸法制备亚快速凝固Cu-15Al-4Fe合金棒材。利用光学显微镜、扫描电镜、能谱仪、X射线衍射、静态浸泡和电化学实验等,研究了合金的组织形貌、成分分布、相组成及耐腐蚀性能。结果表明,亚快速凝固Cu-15Al-4Fe合金呈柱状晶组织,主要由先共析γ2相和(α+γ2)共析体组成。合金在3.5%NaCl和5.0%H2SO4腐蚀液中主要发生脱铝脱铁选择性腐蚀。与5.0%H2SO4溶液相比,合金在3.5%NaCl溶液中存在明显的钝化现象,耐蚀性较高。

Sub-rapidly solidified Cu-15A1-4Fe alloy bar was prepared by copper mould casting. The microstructure, composition distribution, phase constituent and corrosion resistance were inves- tigated using optical microscopy, scanning electron microscopy, energy dispersive spectrometer, X-ray diffraction, static immersion and electrochemical experiment. The results showed that the sub-rapidly solidified Cu-15A1-4Fe alloy present columnar structure composed of γ2 ＋（ α ＋ γ2 ）. Cu-15A1-4Fe alloy suffers from dealuminization and deferrization corrosion in 3.5%NaC1 and 5.0% H2SO4 solution, However, the alloy exhibits a higher corrosion resistance in 3.5%NaCI solution due to evident passivation phenomenon rather than in 5.0%H2SO4 solution.