摘要:在45#钢上化学镀Ni-P-PTFE复合镀层,其工艺流程主要包括化学机械抛光、碱性除油、活化、化学镀和干燥。研究了主盐和还原剂质量浓度、pH、温度以及PTFE体积分数对镀速的影响。观察了Ni-P-PTFE镀层的表面形貌,测试了镀层的摩擦学性能。结果表明:当工艺条件为25 g/L硫酸镍、30 g/L次磷酸钠、10 mL/L PTFE、pH 4.6和温度(92士2)℃时,镀速最佳,镀层的摩擦因数在0.16~0.20之间,具有优良的耐磨性能。 关键词:镍—磷合金;聚四氟乙烯;化学复合镀;镀速;摩擦因数:耐磨性 中图分类号:TQl53 文章标志码:A 文章编号:1004—227X(2009)03—0017—04 Study on deposition rate and tribological properties of electrolessly plated Ni-P-PTFE composite coating//WANG Liu-bin,ZHAO Yong-WU* Abstract:A Ni-P-PTFE composite coating was prepared on 45 steel.The process flow includes chemo—mechanical polishin9,alkaline degreasing,activating,electroless plating,and drying.The effects of the mass concentrations of main salt and reducing agent,pH,temperature and PTFE volume fraction on deposition rate were studied.The surface morphology of the Ni-P-PTFE composite coating was observed and its tribological properties were tested.The results showed that the optimal deposition rate was obtained with25 g/L nickel sulfate,30 g/L sodium hypophosphite,and l o mL/L PTFE at temperature(92 4-2)℃and pH 4.6.The composite coating has a friction factor ranging from0.1 6 t0 0.26.showing good wear resistance.
Keywords:nickel-phosphorus alloy;polytetrafluoroethylene;electroless composite platin9;deposition rate;friction factor;wear resistance
First-author’S address:School of Mechanical Engineerin9,Jiangnan University,WuXi 214122,China
1 前言
Ni-P镀层为非晶态合金镀层,具有高硬度、高导电性以及良好的耐蚀性、耐磨性、可焊性、磁性屏蔽等性能,广泛应用于汽车,、航空、电子、机械、化工和石油工业等领域[l]。PTFE(聚四氟乙烯)粒子是一种干态润滑剂,其表面能非常低,不易黏结,具有良好的自润滑、憎水、憎油性能以及极低的摩擦因数,但硬度低,耐磨能力差[2-4]。将PTFE加入Ni-P化学镀液中,可获得Ni-P-PTFE复合镀层。本研究所获得的Ni-P-PTFE复合镀层性能优良,镀液稳定性好(可达8个周期以上),具有良好的应用前景。 |