Corrosion resistance of biomimetic calcium phosphate coatings on magnesium due to varying pretreatment time

Rapid coating of AZ31 magnesium alloy with calcium deficient hydroxyapatite using microwave energy

“…These advantages enable this novel microwave assisted coating technology to homogeneously produce a crack-free and dense HA coating on the AZ31 alloy in minutes. Moreover, this technique allows us to reduce the immersion time to a few minutes rather than the many hours reported in available HA coating methods [27,28,32,36].…”

“…osseointegration [23][24][25][26]. To date, several forms of calcium phosphate coating have been developed on magnesium and its alloys by various techniques, such as chemical precipitation [19,[27][28][29][30][31][32], electrodeposition [33][34][35], sol-gel [36] and hydrothermal method [37,38]. For example, Yang et al [29] produced hydroxyapatite (HA) coatings on AZ31 alloy by immersing the AZ31 substrate in supersaturated calcification solutions and applying heat treatments afterwards.…”

Improvingin vitrocorrosion resistance of biomimetic calcium phosphate coatings for Mg substrates using calcium hydroxide layer

“…23. The pH of the solution was controlled during the process by dissolving carbon dioxide gas (CO 2 ) in the solution.…”

“…Any defects can lead to corrosion underneath the coating, leading to lower adhesion of the coating and increasing corrosion rates. 23 CaP compounds are much more brittle than the underlying substrate. As such, the likelihood of defects is high for a load bearing implant.…”

Surface modification of magnesium and its biodegradable alloys by calcium orthophosphate coatings to improve corrosion resistance and biocompatibility

“…Furthermore, prior deposition of calcium orthophosphates, the surface of Mg, and its alloys might be chemically treated (e.g., activated) Du et al, 2011;Wang, Guan, et al, 2011;Wang et al, 2010;Wang, Tan, et al, 2011;Wen et al, 2009), alkaline treated Guan et al, 2012;Gray-Munro & Strong, 2009;Wang, Wei, et al, 2009;Xu et al, 2012), anodized Zhang, Ma, et al, 2013), chemically polished Hiromoto et al, 2013;Ohtsu et al, 2013;, 2011cTomozawa et al, 2010), electrochemically polished , etched Song et al, 2013), passivated Gruba c et al, 2013;Kannan & Orr, 2011;Waterman et al, 2011), or prephosphatized Du et al, 2011;Zhang, Ma, et al, 2013), among others ).…”