resumo
The principal possibility to grow layered double hydroxide (LDH) at ambient pressure on plasma electrolytic oxidation (PEO) treated magnesium alloy AZ91 in the presence of chelating agents is demonstrated for the first time. It avoids hydrothermal autoclave conditions, which strongly limit wide industrial application of such coating systems, and the presence of carbonate ions in the electrolyte, which lead to the formation of passive non-functionalizable LDH. A combination of chelating agents (sodium diethylenetriamine-pentaacetate (DTPA) and salicylate) were introduced to the treatment solution. The role of each additive and the influence of treatment bath composition on the LDH formation processes are discussed. A synergistic effect of DTPA and salicylate during LDH formation is discovered and its possible explanation is proposed.
palavras-chave
PLASMA ELECTROLYTIC OXIDATION; LAYERED DOUBLE HYDROXIDE; HYDROTALCITE CONVERSION FILM; ACTIVE CORROSION PROTECTION; AZ31 MAGNESIUM ALLOY; MICRO-ARC OXIDATION; COATINGS; RESISTANCE; ALUMINUM; MICROSTRUCTURE
categoria
Science & Technology - Other Topics
autores
Petrova, E; Serdechnova, M; Shulha, T; Lamaka, SV; Wieland, DCF; Karlova, P; Blawert, C; Starykevich, M; Zheludkevich, ML
Grupos
Projectos
Development and design of novel multiFUNctional PEO COATings (FUNCOAT)
MULTI-functional metallic SURFaces via active Layered Double Hydroxide treatments (MULTISURF)
agradecimentos
This work was partially financed by the European project FUNCOAT (Horizon2020-MSCA-RISE-2018, grant agreement No. 823942). M.Se. and C.B. additionally would like to thank ACTICOAT project (Era.Net RUS Plus Call 2017, Project 477) for the financial support, while E.P. would like to acknowledge the financial support of the European project MULTISURF (Horizon2020-MSCA-RISE-2014, grant agreement No. 645676). The authors thank Anton Davydok for support at the beamline. We also thank PETRA III for granting the P03 proposal I-20190157.