Effect of NaOH on plasma electrolytic oxidation of A356 aluminium alloy in moderately concentrated aluminate electrolyte  

氢氧化钠对中等浓度铝酸盐电解液中A356铝合金等离子体电解氧化的影响

作　　者：Yu-lin CHENG Huan-jun XIE Jin-hui CAO Ying-liang CHENG 程昱琳;谢焕钧;曹金晖;程英亮(湖南大学材料科学与工程学院,长沙410082;中国航发中传机械有限公司,长沙410200;湖南大学化学与化工学院,长沙410082)

机构地区：[1]College of Materials Science and Engineering,Hunan University,Changsha 410082,China [2]AECC Zhongchuan Transmission Machinery Co.,Ltd.,Changsha 410200,China [3]College of Chemistry and Chemical Engineering,Hunan University,Changsha 410082,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第12期3677-3690,共14页中国有色金属学报（英文版）

基　　金：The authors are grateful for the financial support from the National Natural Science Foundation of China(No.51671084).

摘　　要：Plasma electrolytic oxidation(PEO)of cast A356 aluminum alloy was carried out in 32 g/L NaAlO_(2) with the addition of different concentrations of NaOH.The stability of the aluminate solution is greatly enhanced by increasing the concentration of NaOH.However,corresponding changes in the PEO behaviour occur due to the increment of NaOH concentration.Thicker precursor coatings are required for the PEO treatment in a more concentrated NaOH electrolyte.The results show that the optimal NaOH concentration is 5 g/L,which improves the stability of storage electrolyte to about 35 days,and leads to dense coatings with high wear performance(wear rate:4.1×10^(−7) mm^(3)·N^(−1)·m^(−1)).在32 g/L铝酸钠中加入不同浓度的氢氧化钠,对铸造A356铝合金进行等离子体电解氧化(PEO)处理。通过增加NaOH的浓度,铝酸盐溶液的稳定性大大提高。然而,由于氢氧化钠浓度的增加,PEO的行为发生相应的变化。在更高浓度的氢氧化钠电解液中,对A356铝合金进行PEO处理时需要较厚的预生膜。结果表明,NaOH的最佳浓度为5 g/L,可将贮存电解液的稳定性提高至35天,并能获得高耐磨致密陶瓷膜层(磨损率为4.1×10^(−7)mm^(3)·N^(−1)·m^(−1))。

关 键 词：plasma electrolytic oxidation wear resistance sodium aluminate sodium hydroxide A356 alloy 

分 类 号：TG662[金属学及工艺—金属切削加工及机床]