Self-healing property of hydroxyapatite and octacalcium phosphate coatings on pure magnesium and magnesium alloy

Self-healing property of hydroxyapatite and octacalcium phosphate coatings on pure magnesium and magnesium alloy

Type	Journal Article
Author	Sachiko Hiromoto
URL	http://www.sciencedirect.com/science/article/pii/S0010938X15300330
Volume	100
Pages	284-294
Publication	Corrosion Science
Date	November 2015
Abstract	Hydroxyapetite (HAp) and octacalcium phosphate (OCP) coatings were formed on AZ31 alloy and pure Mg. The surfaces were then scratched to expose the metal surface. The specimens were immersed in a cell-culture medium or 0.9% NaCl. Researchers noted that the release of Mg ions was not accelerated by scratching. In both solutions, a corrosion product layer containing Mg and P was formed in the scratches. In other words, the coatings self-healed. The corrosion morphology of HAp-coated AZ31 was examined by periodic medium replacement or using a gelatine-added medium. The former enhanced calcium phosphate precipitation; the latter increased corrosion localization.