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Korrosionsbeständigkeit von stromlosen NiP‐ und NiWP‐Beschichtungen auf der Magnesiumlegierung (MgAl9Zn1)
Author(s) -
Liao Y.,
Zhang S. T.,
Dryfe R.
Publication year - 2011
Publication title -
materialwissenschaft und werkstofftechnik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.285
H-Index - 38
eISSN - 1521-4052
pISSN - 0933-5137
DOI - 10.1002/mawe.201100850
Subject(s) - materials science , coating , corrosion , metallurgy , alloy , magnesium , magnesium alloy , dehydrogenation , polarization (electrochemistry) , chromium , composite material , chemistry , catalysis , biochemistry
The autocatalytic nature of the electroless nickel‐based alloy coating process will inevitably produce H 2 bubbles which may be left in electroless nickel‐based alloy coating. If the H 2 cannot be removed and left in the coating, it can lead to its poor corrosion resistance due to hydrogen cracks. So, the post treatment is an essential step for electroless deposition process. In this paper, electroless Ni–P and Ni–W–P coatings with chromium‐free pretreatment and dehydrogenation post treatment have been successfully prepared on AZ91D magnesium alloy, and the corrosion behaviors of the two kind coating samples in NaCl solution, HCl solution, and H 2 SO 4 solution have been investigated. Both the polarization test and immersion tests show that the electroless Ni–W–P coating has better corrosion resistance than that of electroless Ni–P coating.