(西安理工大學(xué) 材料科學(xué)與工程學(xué)院，西安 710048)
摘 要: 利用交流脈沖微弧氧化電源在碳酸鈉、硅酸鈉和錫酸鈉3種電解液中對LY12鋁合金進(jìn)行微弧氧化處理，通過SEM和XRD觀察分析鋁合金樣品表面形貌和相組成的變化，研究各溶質(zhì)離子對微弧氧化起弧現(xiàn)象及生長曲線的作用規(guī)律。結(jié)果表明：在3種電解液中進(jìn)行微弧氧化處理時(shí)，在硅酸鈉溶液中鋁合金易于起弧，能夠在短時(shí)間、低電壓下獲得高阻抗膜；而在錫酸鈉溶液中鋁合金不能形成高阻抗膜，未發(fā)生起弧現(xiàn)象；鋁合金樣品表面預(yù)先制備高阻抗膜有利于發(fā)生微弧氧化起弧現(xiàn)象；在碳酸鈉和硅酸鈉溶液中，微弧氧化陶瓷膜的后期生長曲線有著相似的變化規(guī)律，在錫酸鈉溶液中樣品表面產(chǎn)生電化學(xué)溶解，不能形成陶瓷膜；鋁合金樣品表面形成高阻抗膜是微弧氧化現(xiàn)象得以進(jìn)行的必要條件。
關(guān)鍵字: LY12鋁合金；微弧氧化；溶質(zhì)離子；高阻抗膜
microarc oxidation coatings on aluminium alloy
（School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048, China）
Abstract: LY12 aluminium alloy was processed by microarc oxidation in Na2CO3, Na2SiO3 and Na2SnO3 solutions using AC electrical source. The effects of solute ions on the surface morphologies and phases of aluminium alloy samples were investigated by SEM and XRD, respectively. The effect rules of arc starting and growing curves were contrastively studied. The results show that in the above three electrolytes, arc starting can occur easily in Na2SiO3 solution, and high impedance coating can be prepared in short time at low voltage. Arc starting phenomenon cannot happen in Na2SnO3 solution. The phenomenon of arc starting will occur easily when high impedance coating occurs on the surface of aluminium alloy sample. Growing curves of ceramic coatings have similar rule during forming microarc oxidation coating in Na2CO3 and Na2SiO3 solutions. The sample is dissolved by galvano-chemistry in Na2SnO3 solution and the ceramic coating cannot be formed. The necessary condition of occurring microarc oxidation phenomenon is that high impedance coating must be formed on the surface of aluminium alloy.
Key words: LY12 aluminium alloy; microarc oxidation; solute ion; high impedance coating
