钢铁酸性直接镀铜工艺

Technology for Direct Copper Plating of Iron and Steel in Acidic Bath

钢铁酸性直接镀铜工艺具有节能、环保双重优点。采用250mL赫尔槽和加热急冷等方法,研究了组合添加剂GB-93在钢铁酸性直接镀铜中对镀层光亮范围、孔隙率、阴极电流效率、镀液深镀能力和镀层与基体结合力的影响。结果表明,通过加入GB-93添加剂,可在钢铁基体上直接电镀出光亮、结合力好的酸性铜层,可用于管件、盲孔件、铸铁件,也可用于滚镀或继续加厚其他镀层。酸性直接镀铜工艺解决了钢铁在碱性无氰镀铜中因钝化而导致结合力不良的问题,亦解决了钢铁管状件在电镀酸铜时内孔易出现铜粉的难题,可以代替剧毒的氰化铜预镀工艺。试验获得最佳工艺条件:20g/L CuSO4·5H2O,40g/L H2SO4,15mL/L GB-93A主光剂,15mL/L GB-93B助光剂,阴极电流电流密度0.8A/dm2,温度30℃,电镀时间3min。在上述工艺条件下,可以得到较高的阴极电流效率和良好的结合力。

The technology for direct copper plating of iron and steel in acidic bath has dual advantages of saving energy and protecting environment as well. Thus the effects of combinatory additives on the brightness scope and porosity of coating, cathodic current efficiency, throwing power of bath, and adhesion to substrate of coating prepared from direct acidic copper plating bath were investigated in a 250 mL Hell cell using heating and sharp cooling method. Results indicated that by introducing GB-93 additive into the direct acidic copper plating bath, it was feasible to prepare bright Cu coating with good adhesion to iron and steel substrate. The Cu coating was applicable to tubes, workpieces with invisible holes, and cast iron wares, and it could also be used for barrel plating or follow-up plating of other coatings. Using the present technology for direct copper plating in acidic bath, it could be feasible to get rid of the poor adhesion of cyanide-free Cu plating by passivation in alkaline bath and eliminate copper particulates around the inner holes of tubular wares subjected to acidic copper electroplating. Thus the established technology could be used to replace toxic cyanide process for copper pre-plating. The optimized formulation was determined as 20 g/L CuSO4·5H2O, 40 g/L H2SO4, 15 mL/L major brightener GB-93 A, 15 mL/L auxiliary brightener GB-93B, and the optimized plating conditions were suggested as cathodic current density of 0. 8 A/dm2, temperature of 30℃, and plating time of 3 min. A high cathodic current efficiency was obtained under the optimized plating conditions, and the resulting Cu coating had good adhesion to the substrate.