LDH conversion films for active protection of AZ31 Mg alloy

Corrosion Protection Behavior of Aluminate Ion-Loaded Layered Double Hydroxide Coating on AZ31 Magnesium Alloy

“…6 Then, corrosion inhibitor-loaded LDH coatings have been developed for Mg and Al alloys and steels to enhance the corrosion protection ability and to add self-healing property. [6][7][8][9][10][11][12][13][14][15] The corrosion inhibitors such as MoO 4 2− , VO 3 − , WO 4 2− , phenyl phosphonic acid (PPA), 2-mercaptobenzothiazole (MBT) and 8-hydroxyquinoline (8HQ) were loaded to the LDH coatings. [10][11][12][13][14][15] Meanwhile, suitable anionic corrosion inhibitors for loading to LDH coatings are still in exploration.…”

“…[6][7][8][9][10][11][12][13][14][15] The corrosion inhibitors such as MoO 4 2− , VO 3 − , WO 4 2− , phenyl phosphonic acid (PPA), 2-mercaptobenzothiazole (MBT) and 8-hydroxyquinoline (8HQ) were loaded to the LDH coatings. [10][11][12][13][14][15] Meanwhile, suitable anionic corrosion inhibitors for loading to LDH coatings are still in exploration. As a corrosion inhibitor for Mg alloys, Na 2 MoO 4 Na 2 SnO 3 and NaVO 3 have been proposed.…”

“…25 To form the corrosion inhibitor-loaded LDH coatings, generally, LDH coatings with NO 3 − or CO 3 − ions in the interlayer (LDHNO 3 or LDHCO 3 ) are formed on the alloys by steam treatment, autoclaving, chemical conversion and electrochemical deposition, and then the interlayer NO 3 − or CO 3 − ions are exchanged with anionic inhibitors in aqueous solutions. [7][8][9][10][11][12][13][14][15] The electrophoretic co-deposition (EP-co-D) method enables the LDH particles, which are pre-loaded with various corrosion inhibitors, to deposit on a variety of metal surfaces together with metallic hydroxide. [26][27][28] We therefore employed the EP-co-D method and developed composite coatings of LDHCO 3 particles and magnesium and aluminum double hydroxide (Mg-Al-DH) on Mg-3Al-1Zn (AZ31) alloy.…”