pH值对42CrMo钢Ni-W-P化学镀液稳定性及镀层性能的影响

Effect of pH Value on Stability of Plating Bath and Performance of Ni-W-P Electroless Coatings on 42CrMo Steel

在42CrMo钢基体上制备了Ni-W-P化学镀层,研究了pH值对镀液稳定性和镀层沉积速度的影响,并对镀层进行了扫描电镜(SEM)观察、能谱分析(EDS)、X射线衍射(XRD)分析及显微硬度、耐磨性和耐蚀性测试。结果表明,当镀液pH值为8.0时,镀液稳定性最好,镀层沉积速度较快。镀层由Ni、Ni5P2、NiW2P3和NiW组成,具有非晶态结构,表面均匀且致密。随着镀液pH值升高,镀层硬度、耐磨性和耐蚀性均呈先升高后降低的趋势。

Electroless Ni-W-P alloy coatings were prepared on the substrate of 42CrMo steel,and the effect of pH value on stability of plating bath and deposition rate of electroless coatings were studied.The electroless coatings were investigated further with scanning electron microscope（SEM）,energy dispersive spectroscopy（EDS）,X-ray diffraction（XRD） analysis and measurements of hardness,wear and corrosion resistance.The experimental results showed that when the pH value was 8.0,plating bath possessed the best stability and the electroless coatings exhibited faster deposition rate.Electroless coatings consisted of the phases Ni,Ni5 P2,NiW2 P3 and NiW,with the noncrystalline structure and homogeneous and compact surface morphology.With the increasing of pH value,the hardness,wear resistance and corrosion resistance of coatings presented a trend of climbing up first and then declining.