Surface modification of magnesium alloy AZ31 by hydrofluoric acid treatment and its effect on the corrosion behaviour

Corrosion resistance of a composite polymeric coating applied on biodegradable AZ31 magnesium alloy

“…One possibility consists of the formation of surface layers with good corrosion resistance. It has been reported that pre-treatment of Mg alloys such as AZ31 with hydrofluoric acid promotes the formation of a magnesium-fluoride-rich coating, increasing the corrosion resistance in aggressive solutions [2][3][4]. However, this pre-treatment is not enough to protect the Mg alloy for long periods in aggressive media, and corrosion proceeds very fast in a short term.…”

Synthesis of γ-Fe2O3, Fe3O4 and Copper Doped Fe3O4 Nanoparticles by Sonochemical Method

“…Figures 3 and 4 show the FTIR spectra of undoped and Cu doped samples. In Figure 3(a), a broad band appears at 3353 cm -1 due to the stretching vibration of O-H (Conceicao et al 2010). A weak broad band is shown around 1600 cm -1 due to bending vibration of H-O-H (Lodhia et al 2010).…”

In vitro degradation behavior and cytocompatibility of biodegradable AZ31 alloy with PEO/HT composite coating

“…After PEO treatment, feature peaks of MgO (JCPDS #45-0946) and MgF 2 (JCPDS #41-1443) appeared, indicating the formation of crystallized MgO and MgF 2 in the PEO coating. As we all know, fluoride acid is always used to passivate the magnesium implants to enhance their corrosion resistance, forming an MgF 2 and MgO containing film [29][30][31]. However, the film formation rate was slow and the thickness of the film was restricted by decreased reaction interface of the dissolved magnesium as the reaction proceeding and the formed film did not produce long-term stable protection for the substrate, presenting many corrosion cracks on its surface.…”