scholarly journals Preparation of medical Mg–Zn alloys and the effect of different zinc contents on the alloy

Author(s):  
Yunpeng Hu ◽  
Xuan Guo ◽  
Yang Qiao ◽  
Xiangyu Wang ◽  
Qichao Lin

AbstractIn recent years, along with the development and application of magnesium alloys, magnesium alloys have been widely used in automotive, aerospace, medicine, sports, and other fields. In the field of medical materials, magnesium not only has the advantage of light weight, high strength, and a density similar to that of human bone, but also has good biocompatibility and promotes the growth of human bone. However, the mechanical properties and corrosion resistance of magnesium alloys need to be further improved to meet the requirements for human biodegradable implants. In this study, three alloys (mass fractions: Mg–10Zn, Mg–20Zn, and Mg–30Zn (wt.%)) were prepared using powder metallurgy by homogeneously mixing powders of the above materials in a certain amount with magnesium as the substrate through the addition of zinc elements, which also have good biocompatibility. The effect of zinc on the microstructure, mechanical properties, wear performance, and corrosion resistance of magnesium–zinc alloys was studied when the zinc content was different. The results show that compared with the traditional magnesium alloy using powder metallurgy, prepared magnesium alloy has good resistance to compression and bending, its maximum compressive stress can reach up to 318.96 MPa, the maximum bending strength reached 189.41 MPa, and can meet the mechanical properties of the alloy as a human bone-plate requirements. On the polarization curve, the maximum positive shift of corrosion potential of the specimens was 73 mv and the maximum decrease of corrosion-current density was 53.2%. From the comparison of the above properties, it was concluded that the three prepared alloys of which Mg–20% Zn had the best overall performance. Its maximum compressive stress, maximum bending strength, and corrosion-current density reached 318.96 MPa, 189.41 MPa and 2.08 × 10−5 A·cm−2 respectively, which are more suitable for use as human implant bone splints in human-body fluid environment.

2015 ◽  
Vol 245 ◽  
pp. 97-102
Author(s):  
Dmitry V. Mashtalyar ◽  
Sergey V. Gnedenkov ◽  
Sergey L. Sinebryukhov ◽  
Igor M. Imshinetsky

Investigation results of the composite coatings obtained on MA8 magnesium alloy by plasma electrolytic oxidation (PEO) and post-treated by electrophoretic deposition of superdispersed polytetrafluoroethylene (SPTFE) are presented. Comprehensive research of electrochemical and mechanical properties of the obtained polymer-containing coatings on the magnesium alloy has been performed. It has been established that composite coatings to decrease the corrosion current density by three orders of magnitude (down to Ic = 2.0×10-10 A/cm2) and the wear by two orders of magnitude (down to 1.2×10-6 mm3/(N·m)), as compared to the basic PEO-coating.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1855
Author(s):  
Yunpeng Hu ◽  
Delong Dong ◽  
Xiangyu Wang ◽  
Hongtang Chen ◽  
Yang Qiao

The magnesium alloys Mg-0.5Mn-2Zn, Mg-1.0Mn-2Zn, and Mg-1.5Mn-2Zn (wt.%) with potential biomedical applications, synthesized by powder metallurgy, were investigated to evaluate the influence of manganese content on their microstructure, mechanical properties, and corrosion resistance. The results show that Mg-Mn-Zn alloys prepared by powder metallurgy reached the maximum compressive stress of 316 MPa and the maximum bending strength of 186 MPa, showing their good resistance to compression and bending, and meeting the mechanical properties required for the human bone plate. With an increase in manganese content, the corrosion resistance improved. In the polarization curve, the maximum positive shift of corrosion potential was 92 mV and the maximum decrease of corrosion current density was 10.2%. It was concluded that, of the alloys tested, Mg-1.0Mn-2.0Zn (wt.%) had the best overall performance, and its maximum compressive stress force and corrosion current density reached 232.42 MPa and 1.32 × 10−5 A·cm−2, respectively, being more suitable for service in human body fluids.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7410
Author(s):  
Jiahui Yong ◽  
Hongzhan Li ◽  
Zhengxian Li ◽  
Yongnan Chen ◽  
Yifei Wang ◽  
...  

The effects of (NH4)2ZrF6 concentration, voltage and treating time on the corrosion resistance of ZK61M magnesium alloy micro-arc oxidation coatings were studied by orthogonal experiments. The SEM result shows that the surface roughness and porosity of MAO coatings increased with (NH4)2ZrF6 concentration, voltage and treating time as a whole, except the porosity decreased with treating time. EDS, XRD and XPS analysis show that (NH4)2ZrF6 was successfully incorporated into coatings by reactive incorporation, coatings are dominantly composed of ZrO2, MgO, MgF2 and amorphous phase Mg phosphate. Potentiodynamic polarization was used to evaluate the corrosion property of coatings. When the concentration of (NH4)2ZrF6 is 6 g/L, the voltage is 450 V, and the treating time is 15 min, the coating exhibits the best corrosion resistance which corrosion current density is four magnitudes lower than substrate attributed to the incorporation of ZrO2 and the deposition of MgF2 in the micropores.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1849
Author(s):  
Yanxia Yang ◽  
Yuanzhi Wu ◽  
Yu Wei ◽  
Tian Zeng ◽  
Baocheng Cao ◽  
...  

Magnesium and its alloys have become potential implant materials in the future because of light weight, mechanical properties similar to natural bone, good biocompatibility, and degradability in physiological environment. However, due to the rapid corrosion and degradation of magnesium alloys in vivo, especially in the environment containing chloride ions, the application of magnesium alloys as implant materials has been limited. Therefore, improving the corrosion resistance of magnesium alloy and ensuring good biocompatibility is the main focus of the current research. In this study, hydroxyapatite coating was prepared on magnesium alloy surface using carboxymethyl cellulose-dopamine hydrogel as inducer to improve corrosion resistance and biocompatibility. Surface characterization techniques (scanning electron microscopy, Fourier-transformed infrared spectroscopy, energy dispersive X-ray spectroscopy- and X-ray diffraction) confirmed the formation of hydroxyapatite on the surface of AZ31 alloy. Corrosion resistance tests have proved the protective effect of Carboxymethyl cellulose-Dopamine/hydroxyapatite (CMC-DA/HA) coating on the surface of AZ31 alloy. According to MC3T3-E1 cell viability and Live/Dead staining, the coating also showed good biocompatibility. The results will provide new ideas for the biological application of magnesium alloys.


2021 ◽  
Vol 8 ◽  
Author(s):  
Zhengyuan Gao ◽  
Chengjin Sun ◽  
Lianteng Du ◽  
Dong Yang ◽  
Xiang Zhang ◽  
...  

In order to enhance the corrosion resistance of AZ31 magnesium alloy, graphene-modified oily epoxy resin coating (G/OEP) were prepared on the surface of magnesium alloy. SEM observations show that graphene has fewer surface defects, and can significantly improve the surface quality of the coating and reduce defects. FI-TR testing shows that coating are mainly composed of epoxy resin (polyurethane) and its corresponding curing agent. Electrochemical testing shows that the coating can provide good corrosion protection for magnesium alloy. Compared with the corrosion current density of magnesium alloy of 6.20 × 10−7 A/cm2, the G/OEP can significantly reduce the corrosion current density to 6.96 × 10−12 A/cm2. Analysis of the morphology of the coating after electrochemical corrosion found that graphene can improve the shielding ability of the coating to corrosive media, and reduce the damage of corrosion to the coating structure, and enhance the corrosion resistance of the coating. The content of graphene for excellent corrosion resistance of coating during this experiment is 0.6 wt%. The graphene can fill the defects generally in the coating during the curing process to prevent substrate from penetration of corrosive media caused by the density and hydrophobicity of coating are increased.


Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1146
Author(s):  
Zhanying Wang ◽  
Ying Ma ◽  
Yushun Wang

Effect of V2O5 additive in silicate-containing electrolyte on AZ91D magnesium alloys treated by micro-arc oxidation (MAO) technology under different loading voltages was investigated. The results showed that vanadium was well up-taken into the coating chemically. Moreover, a new phase of MgV2O4 with spinel structure was obtained in MAO coatings due to V2O5 added into the electrolyte. The MgV2O4 phase was responsible for the coatings exhibiting brown color and also was beneficial to improving the anti-corrosion property. In spotting tests, the corrosion resistances of coatings prepared under the high voltage are about 6–9 times higher than those of the low voltage because of the thicker coatings of the former. In potentiodynamic polarization tests, the coatings’ corrosion resistances were improved with the addition of V2O5, which was more significant under the low voltage than that under the high voltage. When the concentration of V2O5 was 0.2 g/L, the corrosion current density of the coating was the lowest, which means that the coating’s corrosion resistance under the low voltage is the best. Hence, it is necessary to carry out targeted design of the coating’s microstructure according to the different applications.


2017 ◽  
Vol 754 ◽  
pp. 11-14 ◽  
Author(s):  
Marialaura Tocci ◽  
Lorenzo Montesano ◽  
Annalisa Pola ◽  
Marcello Gelfi ◽  
Marina La Vecchia

In the present work, the effect of Cr and Mn addition on corrosion resistance was investigated on AlSi3Mg alloy. Potentiondynamic corrosion tests in a 3.5 wt. % NaCl solution were performed on samples in different heat-treated conditions, and corrosion current density and potential were determined by Tafel method. Brinnel hardness measurements were also carried out in order to couple corrosion resistance with mechanical properties. It was interestingly found that Cr presence enhanced mechanical properties and corrosion resistance in comparison with the base alloy.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1049 ◽  
Author(s):  
Gui Lou ◽  
Shumin Xu ◽  
Xinying Teng ◽  
Zhijian Ye ◽  
Peng Jia ◽  
...  

Magnesium alloys act as ideal biomedical materials with good biocompatibility. In this paper, the extruded biomedical Mg-6Zn-0.5Nd-0.5/0.8Ca alloys were prepared and their microstructure, mechanical properties and corrosion properties were investigated. The results showed that the surfaces of Mg-6Zn-0.5Nd-0.5/0.8Ca alloys extruded at medium temperature were smooth and compact without cracks. The tensile strength and elongation of Mg-6Zn-0.5Nd-0.5/0.8Ca alloys were 222.5 MPa and 20.2%, and 287.2 MPa and 18.4%, respectively. A large number of dislocations were generated in the grains and on grain boundaries after the extrusion. The alloy was immersed in simulating body fluid (SBF) for the weightlessness corrosion, and the corrosion products were analyzed by FTIR, SEM equipped with EDS. It was found that the corrosion rate of Mg-6Zn-0.5Nd-0.5Ca and Mg-6Zn-0.5Nd-0.8Ca alloy were 0.82 and 2.98 mm/a, respectively. Furthermore, the compact layer was formed on the surface of the alloy, which can effectively hinder the permeation of Cl− and significantly improve the corrosion resistance of magnesium alloys.


Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1522
Author(s):  
Zhengyuan Gao ◽  
Dong Yang ◽  
Chengjin Sun ◽  
Lianteng Du ◽  
Xiang Zhang ◽  
...  

Nano Al films were prepared on AZ31 magnesium alloy samples by DC magnetron sputtering. The effects of sputtering power on the microstructure and corrosion resistance of the Al film were investigated. The results show that the surface of aluminum film is dense and polycrystalline state, and it is oriented along the Al (111) crystal plane. The grain size of Al film first increases and then decreases with the increase of sputtering power. When the sputtering power exceeds 100 W, there is no insignificant effect on the orientation of the Al crystals and the corrosion current density of the samples with Al film are reduced by two orders of magnitude. The corrosion resistance of the magnesium alloy samples with the Al film magnetron sputtered varies with the sputtering power. Compared with low sputtering power, the Al film sputtered by high power has the most excellent corrosion resistance, but too high sputtering power will lead to micro cracks on the Al film, which will adversely affect the corrosion resistance.


2014 ◽  
Vol 633-634 ◽  
pp. 879-882 ◽  
Author(s):  
Jing Dong Qiu ◽  
Su Qiu Jia

Based on the traditional direct electroless nickel methods, chemical baths are improved by removing HF. Examinations have been carried out on the Ni-P deposited on the interlayer for morphology, composition and corrosion-resistance by SEM, EDS, XRD and other instruments. A Ni-P film with fine and dense structure was obtained on the AM60B magnesium alloy. It exhibits lower corrosion current density and more positive corrosion potential than the substrate.


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