pH对化学复合镀镍–磷–聚四氟乙烯性能的影响

Effect of pH on properties of electrolessly plated nickel–phosphorus–polytetrafluoroethylene composite coating

考察了pH对45钢上化学复合镀Ni–P–聚四氟乙烯(PTFE)沉积速率和镀层孔隙率、磷含量、表面形貌、耐蚀性、显微硬度和摩擦因数的影响。镀液组成和工艺条件为:NiSO_4·6H_2O 25 g/L,NaH_2PO_2·H_2O 30 g/L,无水乙酸钠20 g/L,柠檬酸20 g/L,硫脲2 mg/L,氟碳型表面活性剂18 mg/L,PTFE 1.0 g/L,温度85℃,时间1 h。pH为5.0时,沉积速率为15.93μm/h,所得为高磷(质量分数8.34%)复合镀层,其显微硬度为163.3 HV,摩擦因数0.25,能耐中性盐雾腐蚀24.5 h。

The effect of pH on the deposition rate,porosity,phosphorus content,surface morphology,corrosion resistance,microhardness,and friction coefficient of electrolessly plated Ni–P–PTFE(polytetrafluoroethylene)composite coating on 45 steel substrate was studied in a bath composed of NiSO4·6H2O 25 g/L,NaH2PO2·H2O 30 g/L,anhydrous sodium acetate 20 g/L citric acid 20 g/L,thiourea 2 mg/L,and fluorocarbon surfactant 18 mg/L at 85℃ for 1 h.The deposition rate was 15.93μm/h when the pH was 5.0,and the composite coating obtained thereat had a high phosphorus content(8.34wt.%),a microhardness of 163.3 HV,and a friction coefficient of 0.25,and was able to endure neutral salt spray corrosion for 24.5 h.