(北京科技大学 新材料技术研究院 材料先进制备技术教育部重点实验室，北京 100083)
摘 要: 采用静态浸泡腐蚀实验、电化学分析方法等研究连续定向凝固方法制备的具有连续柱状晶组织的Cu-12%Al(质量分数，下同)合金在3.5%NaCl(质量分数)溶液和10%HCl(体积分数)溶液中的耐腐蚀性能及腐蚀机理。结果表明：Cu-12%Al合金在3.5%NaCl溶液中的耐腐蚀性能可达到耐蚀级。虽然在40 ℃以下的10%HCl溶液中该合金的耐腐蚀性能可达到耐蚀级，但在40 ℃以上的10%HCl溶液中的耐腐蚀性能欠佳。连续柱状晶组织Cu-12%Al合金的耐腐蚀性能优于Al含量为5%~11%的传统铝青铜和QBe2合金的耐腐蚀性能，但劣于QBe2.15合金的耐腐蚀性能。在3.5% NaCl溶液和10%HCl中连续柱状晶组织Cu-12%Al合金的自腐蚀电位分别为−271 mV(vs SCE)和−333 mV (vs SCE)。腐蚀发生后试样表面的Al元素含量明显下降，腐蚀机制为脱铝腐蚀。
关键字: Cu-12%Al合金；连续柱状晶组织；耐腐蚀性能；脱铝腐蚀
（Key Laboratory for Advanced Materials Processing, Ministry of Education,
Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The corrosion resistances and corrosion mechanism of a Cu-12%Al (mass fraction) alloy with continuous columnar-grained (CCG) microstructure fabricated by unidirectional solidification casting were investigated by static immersing tests and electrochemistry analysis in 3.5%NaCl (mass fraction) and 10%HCl (volume fraction) solutions. The results show that the corrosion resistances of the CCG Cu-12%Al alloy in 3.5%NaCl solution can achieve corrosion- resistant level. The corrosion resistances in 10%HCl solution at a temperature below 40 ℃ can achieve corrosion-resistant level, however, if the temperature is above 40 ℃, the alloy has poor corrosion resistance in 10%HCl solution. In 10%HCl solution, the corrosion resistance of the CCG Cu-12%Al alloy is superior to that of the conventional Al bronzes with Al content of 5%~11% and QBe2 alloy, but inferior to that of QBe2.15 alloy. The corrosion potentials of the CCG Cu-12%Al alloy are −271 mV (vs SCE) in 3.5%NaCl and −333 mV (vs SCE) in 10%HCl. The content of Al in the surface layer of the alloy significantly decreases after corrosion, which proves that the Cu-12%Al alloy suffers dealuminization corrosion in 3.5%NaCl and 10%HCl solutions.
Key words: Cu-12%Al alloy; continuous columnar-grained microstructure; corrosion resistance; dealuminization corrosion
