Based on the previous works, the effects of mass concentration of potassium pyrophosphate, current, temperature, and dosage of JZ-1 additive on thickness and tin content of the cyanide-free barrel plated Cu-Sn alloy coating on low carbon steel substrate were studied by orthogonal test under the following conditions: Cu2P2O7-4H2O 20 g/L, Sn2P2O71 g/L, K2HPO4-3H2O 60 g/L, pH 8.5, barrel rotation speed 15 r/min, plating time 1 h, and cycle filtration required. The optimal process conditions were determined, and the effects of plating current, temperature, and time on the composition and deposition rate of Cu-Sn coating were discussed. It is proved that a Cu-Sn alloy coating with at least 5 |im thickness and 9%-11 % tin can be obtained with K4P2O7 300-350 g/L and JZ-1 additive 0.5 mL/L at temperature 30-35 °C and current density 0.38-0.48 A/dm2. The low-tin Cu-Sn alloy coating features a bright and golden appearance, good adhesion to the substrate, and favorable hardness and corrosion resistance, which is an alternative tornnickel pre-plating and cyanide copper pre-plating on iron and steel substrates.%在前期研究的基础上,在Cu2P2O7·4H2O 20 g/L、Sn2P2O71g/L、K2HPO4·3H2O 60g/L、pH=8.5、滚筒转速15 r/min、滚镀时间1h、采用循环过滤的工艺条件下,通过正交试验研究了焦磷酸钾质量浓度、电流、温度和添加剂JZ-1的用量对低碳钢上无氰滚镀铜锡合金(低锡)镀层厚度和含锡量的影响,确定了最优的工艺条件,并探讨了滚镀电流、温度和时间对铜锡合金镀层的组成与镀速的影响.试验证明,当K4P2O7为300 ～ 350g/L、添加剂JZ-1为0.5mL/L、镀液温度为30～35℃、电流密度为0.38 ～ 0.48 A/dm2时,可获得厚度5 μm以上、锡含量为9％～ 11％的铜锡合金镀层,其外观光亮、金黄,与钢铁基体的结合力良好,具有一定的硬度与耐腐蚀性能,可以替代钢铁基材预镀镍和氰化预镀铜工艺.
展开▼
