Improvement in corrosion resistance and biocompatibility of AZ31 magnesium alloy by NH2+ ions

Abstract

Magnesium alloys have been considered to be favorable biodegradable metallic materials used in orthopedic and cardiovascular applications. We introduce NH + 2 to the AZ31 Mg alloy surface by ion implantation at the energy of 50 KeV with doses ranging from 1×10 16 ions/cm 2 to 1×10 17 ions/cm 2 to improve its corrosion resistance and biocompatibility. Surface morphology, mechanical properties, corrosion behavior and biocompatibility are studied in the experiments. The analysis confirms that the modified surface with smoothness and hydrophobicity significantly improves the corrosion resistance and biocompatibility while maintaining the mechanical property of the alloy.

Degradation protection and enhanced biocompatibility of Mg alloys pretreated with plasma proteins

“…This is due to that Zn ions dissolve more easily in DMEM due to galvanic corrosion of the untreated ZK60 alloy, which is consistent with the biocompatibility results in the literature. [4][5][6] The protein layer absorbed on the surface of ZK60 alloy effectively delays the galvanic corrosion of the zinc-containing sample, resulting in the reduced metal ions concentrations and improved cell proliferation.…”

“…Mg alloy biomaterials exhibit good biocompatibility and degradability, thus, they have unique advantages as implantable materials and are widely used in orthopedics, cardiovascular, and other medical fields 1,2 . As an implantable bone substitute, Mg alloy has an elastic modulus of 41–45 GPa similar to that of human bone, which can effectively avoid stress‐shielding effects 3,4 . Mg alloy also has excellent mechanical properties and lightweight ratio, providing good mechanical support for implantation; in addition, it does not require a second operation for its removal after the tissue heals because it degrades completely, thus reducing pain 5,6 .…”

“…In our previous work, the degradation performance in Hank's solution and the in vitro biocompatibility of Mg alloys (ZK60 and AZ31) have been systematically investigated. 4,6 Moreover, Wang et al investigated the effects of eight alloying elements, including Ca, Li, Ce, Y, Zr, Mn, Zn, and Cu, on the adsorption behavior of fibrinogen on the surface of Mg alloys using molecular dynamic (MD) simulations and experimental methods. 17 Hence, this work aims to investigate the biocompatibility of ZK60 and AZ31 Mg alloys in plasma protein environment, and to elucidate the mechanism of proteins on the in vitro degradation of Mg alloys through MD theoretical simulation at atomic level.…”

Corrosion resistance and tribological behavior of ZK30 magnesium alloy coated by plasma electrolytic oxidation

“…Prior to in vitro immersion tests, samples were rinsed with distilled water and dried in open air. ZK30 and ZK60 samples were submerged in Hank's solution with a volume to area ratio of 40 mL cm -2 and at a temperature of 36.5 ± 0.5 °C, according to the ASTM-G31-72 standard [26] and the procedure followed by X. Wei et al [27]. The samples were subjected to the immersion tests for a maximum duration of 96 h. The electrolyte was refreshed every 24 h. At an interval of every 24 h, the samples were taken out of the solution and immersed in a chromic acid solution (200 g L -1 CrO3 + 10g L -1 AgNO3) for 2-3 min to remove the oxides [28], dried with a jet of cold air and weighed.…”

Electrochemical evaluation of AZ31 Mg alloy in corrosion protection of titanium silicon oxide from Earle's solution

“…1,2 Mg alloys are good biocompatible materials and are used widely in biomedical applications. [3][4][5] The mechanical properties (Young's modulus 44 GPa and density 1.74 g cm À3 ) of Mg alloys are identical to human bone compared to other biodegradable materials such as Fe and Zn-based alloys. 6,7 The superior properties of Mg alloys are bioresorbability, biocompatibility, nontoxicity and non-rejection of revision surgery of the implant.…”