Preparation and characterization of NiCrAlY/nano-YSZ/PCL composite coatings obtained by combination of atmospheric plasma spraying and dip coating on Mg–Ca alloy

Preparation and characterization of NiCrAlY/nano-YSZ/PCL composite coatings obtained by combination of atmospheric plasma spraying and dip coating on Mg–Ca alloy

Type	Journal Article
Author	H. R. Bakhsheshi-Rad
Author	E. Hamzah
URL	http://www.sciencedirect.com/science/article/pii/S0925838815314523
Volume	658
Pages	440-452
Publication	Journal of Alloys and Compounds
Date	February 15, 2016
Abstract	A triple-layer NiCrAlY/nano-yttria stabilized zirconia (nano-YSZ)/polycaprolactone (PCL) coating was deposited on Mg–Ca alloy by innovative combination of atmospheric plasma spraying (APS) and dip coating methods, with the objective of further enhancement of the corrosion and mechanical properties of the Mg alloy. The compressive strength of the triple-layer plasma/polymer coating is higher than that of the plasma coated and uncoated samples after immersion in 3.5 wt% NaCL solution. However, both single and dual-layer plasma coatings exhibited better bonding strength than the triple-layer plasma/polymer coating. The corrosion resistance of Mg alloy was significantly improved by triple-layer NiCrAlY/nano-YSZ/PCL coating this was inferred from the lower corrosion current; 0.14 μA/cm2 versus 285.3 μA/cm2 for the uncoated Mg alloy, the higher corrosion potential; −1252.8 versus −1631.4 mVSCE, and the significantly lower corrosion rate; 0.003 versus 6.51 mm/yr. Authors propose a corrosion mechanism for the single-, double- and triple-layer coated Mg alloy was proposed.