铝合金无铬化学转化膜工艺研究  

Study on chrome-free chemical conversion coating process for aluminum alloy

作　　者：陈泽民[1] 高梦颖[1] 杨红贤 

机构地区：[1]廊坊师范学院化学与材料科学学院,河北廊坊065000

出　　处：《电镀与涂饰》2015年第7期391-395,共5页Electroplating & Finishing

摘　　要：以单宁酸和氟钛酸盐为主体原料,加入硝酸铜,在铝合金表面形成化学转化膜,以硫酸铜点滴试验为依据,通过单因素实验优化了铝合金非铬转化膜工艺条件：乙二胺四乙酸二钠0.5 g/L,氟钛酸钾1.0 g/L,氟硼酸铵0.25 g/L,单宁酸0.8 g/L,马日夫盐0.5 g/L,A液（含Cu（NO3）2·3H2O和氟钛酸）25 m L/L,化学转化液的p H 2.5~3.5,温度35°C,浸渍时间15 min。该工艺可在铝合金表面形成完整致密的金黄色非晶态化学转化膜,硫酸铜点滴时间达到6 min,具有较好的抗蚀性能。A chemical conversion coating was formed on surface of aluminum alloy using tannic acid and fluotitanate as main materials with the addition of copper nitrate. According to copper sulfate dropping corrosion test, the process conditions for chrome-free conversion coating on aluminum alloy were optimized as follows： disodium ethylenediaminetetraacetate 0.5 g/L, potassium fluotitanate 1.0 g/L, ammonium fluoroborate 0.25 g/L, tannic acid 0.8 g/L, manganese dihydrogen phosphate 0.5 g/L, solution A（composed of Cu（NO3）2·3H2O and fluotitanic acid） 25 m L/L, temperature 35 °C, bath p H 2.5-3.5, and immersion time 15 min. The process can produce complete and compact chemical conversion coatings with amorphous structures in golden yellow on the surface of aluminum alloy, which has a copper sulfate dropping corrosion resistance up to 6 min, presenting a good corrosion resistance.

关 键 词：铝合金 化学转化膜 单宁酸 氟钛酸盐 耐蚀性 

分 类 号：TG178[金属学及工艺—金属表面处理]