(北京科技大學(xué) 新材料技術(shù)研究院 材料先進制備技術(shù)教育部重點實驗室，北京 100083)
摘 要: 采用靜態(tài)浸泡腐蝕實驗、電化學(xué)分析方法等研究連續(xù)定向凝固方法制備的具有連續(xù)柱狀晶組織的Cu-12%Al(質(zhì)量分?jǐn)?shù)，下同)合金在3.5%NaCl(質(zhì)量分?jǐn)?shù))溶液和10%HCl(體積分?jǐn)?shù))溶液中的耐腐蝕性能及腐蝕機理。結(jié)果表明：Cu-12%Al合金在3.5%NaCl溶液中的耐腐蝕性能可達到耐蝕級。雖然在40 ℃以下的10%HCl溶液中該合金的耐腐蝕性能可達到耐蝕級，但在40 ℃以上的10%HCl溶液中的耐腐蝕性能欠佳。連續(xù)柱狀晶組織Cu-12%Al合金的耐腐蝕性能優(yōu)于Al含量為5%~11%的傳統(tǒng)鋁青銅和QBe2合金的耐腐蝕性能，但劣于QBe2.15合金的耐腐蝕性能。在3.5% NaCl溶液和10%HCl中連續(xù)柱狀晶組織Cu-12%Al合金的自腐蝕電位分別為−271 mV(vs SCE)和−333 mV (vs SCE)。腐蝕發(fā)生后試樣表面的Al元素含量明顯下降，腐蝕機制為脫鋁腐蝕。
關(guān)鍵字: Cu-12%Al合金；連續(xù)柱狀晶組織；耐腐蝕性能；脫鋁腐蝕
（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
