Improvement of anti-corrosive and anti-oxidative properties of electroless Ni-P coating

ABSTRACT

In order to improve the anti-corrosive and anti-oxidative properties of electroless Ni-P coating (ENPC), a vanadium conversion coating (VCC) was fabricated on the surface of the ENPC. SEM images and EDX line scanning spectra indicate that as-prepared VCC is supposed to be a thin film with a thickness of a few nanometres. XPS analyses demonstrate that the VCC is mainly consisted of V₂O₅ or V₂O₅·nH₂O. The acid exposure test data indicate that the VCC-treated ENPC, compared with the pristine one, demonstrates a highly enhanced anti-oxidative property. Furthermore, the result of neutral salt spray test manifests that the VCC-treated ENPC has also a highly enhanced anti-corrosive property, which is further confirmed by the result of electrochemical corrosion test.

KEYWORDS:

• Chromate-free
• electroless Ni-P coating
• vanadium conversion coating
• anti-corrosive property
• anti-oxidative property

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Natural Science Foundation of Sichuan Engineering Technical College: [Grant Number YJ2016KY-01].