Improvement of AZ91 Alloy Corrosion Properties by\nDuplex NI-P Coating Deposition

0524658 - ÚFM 2021 RIV CH eng J - Journal Article
Wasserbauer, J. - Buchtíková, M. - Tkacz, J. - Fintová, Stanislava - Minda, J. - Doskočil, L.
Improvement of AZ91 Alloy Corrosion Properties by
Duplex NI-P Coating Deposition.
Materials. Roč. 13, č. 6 (2020), č. článku 1357. E-ISSN 1996-1944
Institutional support: RVO:68081723
Keywords : Ni-P coating * AZ91 magnesium alloy * electroless deposition * corrosion * electrochemical test
OECD category: Coating and films
Impact factor: 3.623, year: 2020
Method of publishing: Open access
https://www.mdpi.com/1996-1944/13/6/1357

The corrosion behavior of duplex Ni-P coatings deposited on AZ91 magnesium alloy was
studied. The electroless deposition process of duplex Ni-P coating consisted in the preparation of
low-phosphorus Ni-P coating (5.7 wt.% of P), which served as a bond coating and high-phosphorus
Ni-P coating (11.5 wt.% of P) deposited on it. The duplex Ni-P coatings with the thickness of 25, 50,
75 and 100 m were deposited on AZ91 magnesium alloy. The electrochemical corrosion behavior
of coated AZ91 magnesium alloy was investigated by electrochemical impedance spectroscopy
and potentiodynamic polarization method in 0.1 M NaCl. Obtained results showed a significant
improvement in the corrosion resistance of coated specimens when compared to uncoated AZ91
magnesium alloy. From the results of the immersion tests in 3.5 wt.% NaCl, 10% solution of HCl and
NaOH and 5% neutral salt spray, a noticeable increase in the corrosion resistance with the increasing
thickness of the Ni-P coating was observed.
Permanent Link: http://hdl.handle.net/11104/0310353