三价铬镀铬工艺初探  

Chromium (Ⅲ) Electroplating Technology

作　　者：周琦[1] 郝清伟[1] 张春丽[1] 邵忠财[1] 

机构地区：[1]沈阳工业学院,辽宁沈阳110045

出　　处：《材料保护》2004年第6期22-23,25,共3页Materials Protection

摘　　要：传统的镀铬是在含有六价铬的电镀液中进行的 ,六价铬对环境严重的危害 ,促进了三价铬镀铬工艺的发展。在铁基体上选取不同的三价铬镀铬配方进行试验 ,以铅板或石墨为阳极 ,2 0钢试片作阴极 ,对试片除油除锈后 ,直接进行三价铬镀铬 ,经过对镀层的外观、厚度及结合力的比较取舍 ,获得了外观及结合力较好的配方 :5 2g/LCr3 + ;4 0g/LKCl;10g/LKBr;4 6g/LHCOOH ;5 3g/LNH4Cl;15 0g/L (NH2 ) 2 CO ;10g/LH3 BO3 及少量的添加剂 ,以阳极石墨为基础 ,研究了不同种类及不同用量的润湿剂对镀层外观和孔隙率的影响 ,最终选定了对于三价铬镀铬配方较佳的润湿剂及其用量范围。对镀铬层用碳酸钠和磷酸钠进行中和浸渍 ,时间为 3～ 5min ,可以减轻三价铬镀层发黄的问题。该工艺条件 :DK=10～ 15A/dm2 ,10～ 2 0℃带电下槽 ,pH值为 0 .5～ 1.0 ,电镀液的稳定性为 12A·h/L。镀层细致、光亮、孔隙率低 ,而且可以在常温下操作 ,节约能源。Electroplating chromium is conducted in electrolytes containing chromium (Ⅵ) traditionally. Chromium(Ⅲ) electroplating technology is developed for serious environmental hazard of chromium (Ⅵ). Different chromium(Ⅲ) electroplating formula were selected for iron substrate. The lead plate or graphite was employed as anode and 20 steel as cathode. The coupon was electroplated directly from electrolytes containing chromium(Ⅲ) salt after cleaning and etching.The optimum formula, composed of 52 g/L Cr^(3+),40 g/L KCI,10 g/L KBr, 46 g/L HCOOH, 53 g/L NH4C1, 150 g/L (NH_2)_2CO, 10 g/L H3BO3 and a small quantity additives, is acquired by comparing the appearance, thickness and adhesion of deposit. Using graphite as anode, the effects of wetting agents with different sorts and concentrations on appearance and porosity of deposit were investigated to determine wetting agent and its concentration rang better for chromium (Ⅲ) plating. The yellowing problem of chromium(Ⅲ) plating is lightened by immersion neutralising in Na2CO3 and Na3PO4 solutions for 3～5 minutes.The stability of electrolyte is 12 A. h/L while electroplating under the conditions of D_K=10～15 A/dm^2,t=10～25℃,pH=0.5～1.0. The deposit is fine and brightness with low porosity and energy saving for operating at room temperature.

关 键 词：电镀铬 三价铬 润湿剂 工艺 

分 类 号：TQ153.1[化学工程—电化学工业]