A process for electroplating low-phosphorus Zn-Fe-P ternary alloy was developed. The bath composition and operation conditions are as follows: ZnCl2 70-100 g/L, KC1 160-200 g/L, CH3COONa 5-40 g/L, CH3COOH 2-10 mL/L, FeCl2 5-10 g/L, stabilizing agent 5-30 g/L, phosphorus-containing refining agent 0.5-20.0 g/L, brightening agent 15-25 mL/L, room temperature, pH 2.5-4.0, and current density 0.5-2.0 A/dm2. The throwingrnpower, current density range for obtaining bright coatings, corrosion inhibition performance, and aging resistance of the plating bath were tested. The adhesion strength of the Zn-Fe-P coating was determined by thermal shock and bending tests. The microscopic morphology was analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The corrosion resistance was examined by polarization curve measurement in 5wt% NaCl solution and neutral salt spray (NSS) test. The novel Zn-Fe-P ternary alloy plating process features low cost and high stability, and the coatings obtained have good resistance to thermal shock and corrosion.%开发了一种锌铁低磷三元合金电镀工艺,镀液组成及工艺条件为:ZnCl270～100g/L,KCl160～200g/L,CH3COONa5～40g/L,CH3COOH 2～10mL/L,FeCl25～10g/L,稳定剂5～30g/L,含磷细化剂0.5～20.0g/L,光亮剂15～25 mL/L,室温,pH 2.5～4.0,电流密度0.5～2.0A/dm2.测试了镀液的深镀能力、光亮电流密度范围、缓蚀效果及耐老化性能.以热震法和弯曲法测试了镀层的结合力,采用扫描电镜和透射电镜分析了镀层的微观形貌.通过在5％(质量分数)NaCl溶液中的极化曲线测量以及中性盐雾试验,考察了镀层的耐蚀性.该新型锌铁磷三元合金工艺成本低、稳定,镀层耐热冲击和耐腐蚀的性能优良.
展开▼
