(1. 中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083；2. 中國鋁業(yè)公司 鄭州研究院，鄭州 450041)
摘 要: 在AlCl3-NaCl-KCl低溫共融鹽中，添加無水MnCl2，接通直流電在鐵片上獲得Al-Mn合金鍍層。用掃描電鏡、能量色散譜、X射線衍射和極化曲線對分別對該合金鍍層的形貌、組成、相結(jié)構(gòu)及耐腐蝕性能進(jìn)行測試。結(jié)果表明：純鋁鍍層表面呈針狀，錳質(zhì)量分?jǐn)?shù)9.20%的鍍層表面呈花狀，錳質(zhì)量分?jǐn)?shù)25.43%的鍍層表面有無規(guī)則瘤節(jié)狀凸起物且晶界模糊，而錳質(zhì)量分?jǐn)?shù)達(dá)到34.42%時，晶粒細(xì)化，晶界清晰；合金鍍層中錳質(zhì)量分?jǐn)?shù)與熔鹽中無水MnCl2的質(zhì)量分?jǐn)?shù)呈線性關(guān)系；錳質(zhì)量分?jǐn)?shù)為20.84%~29.74%的鍍層為單一的非晶態(tài)結(jié)構(gòu)，錳質(zhì)量分?jǐn)?shù)高于29.74%的鍍層為Al8Mn5晶體與非晶態(tài)的雙相結(jié)構(gòu)；合金鍍層的點(diǎn)蝕電壓比純鋁鍍層高180~360 mV，單相非晶態(tài)合金鍍層的耐蝕性優(yōu)于雙相鍍層。
關(guān)鍵字: Al-Mn合金；低溫熔融鹽；電鍍；微觀結(jié)構(gòu)；耐蝕性
（1. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;2. Zhengzhou Research Institute, Aluminum Corporation of China, Zhengzhou 450041, China）
Abstract:Al-Mn alloy coatings were obtained on iron substrate from AlCl3-NaCl-KCl low temperature molten salt with a controlled content of anhydrous MnCl2. SEM, EDS, XRD and polarization curves were used to investigate the composition, surface morphology, phase structure and corrosion resistance of the obtained deposits. The results show that the surface of the obtained pure aluminum coating is acicular, while the coating with 9.20%(mass fraction) Mn is flowery-like and irregular tumor-like outshoots and dark grain boundaries exist in the coating with 25.43% Mn. As Mn content achieves 34.42%, the obtained crystal is fined and the grain boundaries turn clear. The content of manganese increases linearly with increasing content of MnCl2. A single amorphous phase alloy coating is obtained when Mn content is between 20.84% and 29.74%, when the content of Mn beyond 29.74%, a mixture of amorphous and Al8Mn5 was obtained. The pitting potential of the obtained pure aluminum coating is enhanced by about 180−360 mV when added with Mn. The corrosion resistance of single amorphous phase alloys is better than that of the duel-phase structure deposits.
Key words: Al-Mn alloys; low temperature molten salt; electroplating; microstructure; corrosion resistance
