Fei’s square wave regulation on composition and amorphization of Ni-P alloy coating

Abstract

In order to solve the problem that the Ni-P alloy coating with an amorphous structure having excellent corrosion resistance cannot be obtained in the conventional electrodeposition process, Ni-P alloy coatings were prepared on the basis of a high-speed electroplating bath, and the law of influence of waveform parameters on the amorphization process of Ni-P alloy coatings was studied by using Fei’s square wave electrodeposition method. The micromorphologies of Ni-P alloy coatings were characterized by scanning electron microscopy (SEM) under different conditions. The P content of the coatings was analyzed by energy spectrum analysis (EDS). Structural changes of phase of the coatings were investigated by X-ray diffraction (XRD). The optimized pulse process parameters are: the average current density is 15 A/dm2, the inverse pulse coefficient is 0.3, the duty ratio is 0.6, and the frequency is 1 Hz. The results show that by adjusting Fei’s square wave pulse parameters, the fully amorphous Ni-P alloy coating can be electrodeposited, which has the features of high P content up to 17.93% (mass fraction), negligible nickel crystal diffraction peaks, and the smooth surface with a bright appearance as well.

Keywords

• amorphization
• electrodeposition
• fei’s square wave
• high p
• nickel-phosphorus alloy