scholarly journals Thermally Induced Gradient of Properties on a Superhydrophobic Magnesium Alloy Surface

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
Kirill A. Emelyanenko ◽  
Alexander G. Domantovsky ◽  
Elizaveta V. Chulkova ◽  
Alexandre M. Emelyanenko ◽  
Ludmila B. Boinovich
Keyword(s):  
Magnesium Alloy ◽  
Oxide Layer ◽  
Magnesium Oxide ◽  
Magnesium Alloys ◽  
Laser Processing ◽  
Prolonged Exposure ◽  
Industrial Applications ◽  
Alloy Surface ◽  
Internal Stresses ◽  
Nanosecond Laser

Fabrication of superhydrophobic coatings for magnesium alloys is in high demand for various industrial applications. Such coatings not only extend the service life of metal structures, but also impart additional useful functional properties to the coated surface. In this study, we show that nanosecond laser processing of long, thin stripes of magnesium alloys followed by the deposition of a hydrophobic agent onto the magnesium oxide layer is a simple, convenient, and easily reproducible method for obtaining superhydrophobic surfaces with property gradient along the sample. The mechanism of the gradient in wettability and electrochemical properties of the magnesium alloy surface is discussed based on the high-temperature growth of magnesium oxide and its following degradation. The latter is related to the development of internal stresses and the formation of cracks and pores within the oxide layer at prolonged exposure to high temperatures during the interaction of a laser beam with the substrate. The effect of heating during laser processing of magnesium materials with limited sizes on the protective properties of the forming coatings is elucidated.

Determination of Lower-Bound Ductility for AZ31 Magnesium Alloy by Use of the Bulge Specimens

2006 ◽  
Vol 129 (3) ◽  
pp. 407-413 ◽  
Author(s):  
Rimma Lapovok ◽  
Peter D. Hodgson
Keyword(s):  
Magnesium Alloy ◽  
Lower Bound ◽  
Magnesium Alloys ◽  
High Sensitivity ◽  
Processing Parameters ◽  
Industrial Applications ◽  
Compression Tests ◽  
Forming Technology ◽  
Element Simulation ◽  
The Moment

Despite the high demand for industrial applications of magnesium, the forming technology for wrought magnesium alloys is not fully developed due to the limited ductility and high sensitivity to the processing parameters. The processing window for magnesium alloys could be significantly widened if the lower-bound ductility (LBD) for a range of stresses, temperature, and strain rates was known. LBD is the critical strain at the moment of fracture as a function of stress state and temperature. Measurements of LBD are normally performed by testing in a hyperbaric chamber, which is highly specialized, complex, and rare equipment. In this paper an alternative approach to determine LBD is demonstrated using wrought magnesium alloy AZ31 as an example. A series of compression tests of bulge specimens combined with finite element simulation of the tests were performed. The LBD diagram was then deduced by backward calculation.

Ecological Joining Process of AZ31B Magnesium Alloy

2021 ◽  
Vol 890 ◽  
pp. 76-81
Author(s):  
Lia Nicoleta Boțilă ◽  
Radu Cojocaru ◽  
Victor Verbiţchi
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Industrial Applications ◽  
Low Density ◽  
High Corrosion Resistance ◽  
Metal Structures ◽  
Complex Metal ◽  
Magnesium Alloy Az31b ◽  
Joining Process

Due to their properties (low density, high corrosion resistance, easy to process), magnesium alloys are used in all important industrial fields (aeronautics, automotive, transport, etc.). Magnesium is the lightest metal for complex metal structures with a density 2-3 times lower than that of aluminum and a quarter than that of steel. The possibility of joining magnesium with other materials allows a greater flexibility in designing and increasing the number of applications for light alloys.This paper presents results obtained by ISIM Timisoara for FSW welding of magnesium alloy AZ31B. Considering the difficulties that arise when welding magnesium alloys using classical processes, it can be assumed that by applying the FSW process for joining these types of materials, the results obtained are very good and can substantiate industrial applications.

scholarly journals Construction of Chi(Zn/BMP2)/HA composite coating on AZ31B magnesium alloy surface to improve the corrosion resistance and biocompatibility

2021 ◽  
Vol 10 (1) ◽  
pp. 870-882
Author(s):  
Qiuyang Zhang ◽  
Li Zhang ◽  
Minhui Yang ◽  
Qingxiang Hong ◽  
Zhongmei Yang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Composite Coating ◽  
Magnesium Alloys ◽  
Bone Morphogenetic Protein 2 ◽  
Alloy Surface ◽  
Zinc Ions ◽  
Hexadecanoic Acid ◽  
Az31b Magnesium Alloy ◽  
E Coli

Abstract As biodegradable orthopedic implant materials, magnesium alloys have been attracted enough attentions recently. However, too fast degradation in vivo, limited biocompatibilities, and insufficient antibacterial properties are three main challenges at present. In order to solve these problems, a multifunctional composite coating of Chi(Zn/BMP2)/HA was constructed on AZ31B magnesium alloy surface, successively by the alkali heating treatment, self-assembly of 16-phosphonyl-hexadecanoic acid, in situ immobilization of Chi(Zn/BMP2) (chitosan, zinc ions, and bone morphogenetic protein 2), and the deposition of HA (hydroxyapatite). The results of ATR-FTIR (attenuated total reflection Fourier transform infrared spectrum) spectra and elemental compositions confirmed that 16-phosphonyl-hexadecanoic acid, Chi(Zn/BMP2), and HA were successfully immobilized on the surface. Compared with Mg, Mg-OH, Mg-16, and Mg-Chi(Zn/BMP2), Mg-Chi(Zn/BMP2)/HA with the concave–convex structure surface significantly enhanced the hydrophilicity and corrosion resistance. On the other hand, Mg-Chi(Zn/BMP2)/HA coating also showed excellent biocompatibilities, which not only significantly promoted the osteoblast adhesion and proliferation, but also upregulated ALP and OCN expression of osteoblasts. Furthermore, due to the synergistic antibacterial effect of zinc ions and chitosan, Mg-Chi(Zn/BMP2)/HA showed a good antibacterial property against Escherichia coli (E. coli). Therefore, it can be said that the method used in this work has a good application prospect in improving the corrosion resistance, biocompatibility of magnesium alloys, and inhibiting infections against E. coli.

Effects of Gd and Er on the Ignition-Proof Properties of Magnesium Alloy

2011 ◽  
Vol 239-242 ◽  
pp. 122-126
Author(s):  
Zhao Hui Wang ◽  
Xu Dong Wang ◽  
Shu Bo Li ◽  
Wen Bo Du
Keyword(s):  
Magnesium Alloy ◽  
Oxide Layer ◽  
Magnesium Alloys ◽  
Ignition Point

The effects of Gd and Er on ignition-proof behavior of magnesium alloys were investigated. The XRD, SEM and EDS were used to study the ignition-proof performance, oxide products and oxide layer morphology of these alloys. The results indicate that the proper addition of Gd and Er can increase the ignition point of the magnesium alloy. The better ignition-proof property can be obtained after the addition of Er in the Mg-Gd alloy. The mechanism of ignition-proof of magnesium alloy containing Gd and Er are also discussed in this work.

Utilisation of High-Energy Heat Sources in Magnesium Alloy Surface Layer Treatment

2013 ◽  
Vol 58 (2) ◽  
pp. 619-624 ◽  
Author(s):  
M. Szafarska ◽  
J. Iwaszko ◽  
K. Kudła ◽  
I. Łegowik
Keyword(s):  
Surface Layer ◽  
Magnesium Alloy ◽  
Physicochemical Properties ◽  
Treatment Effectiveness ◽  
High Energy ◽  
Alloy Surface ◽  
Heat Sources ◽  
X Ray ◽  
Additional Equipment ◽  
Alloy Surface Layer

The main aim of the study was the evaluation of magnesium alloy surface treatment effectiveness using high-energy heat sources, i.e. a Yb-YAG Disk Laser and the GTAW method. The AZ91 and AM60 commercial magnesium alloys were subject to surface layer modification. Because of the physicochemical properties of the materials studied in case of the GTAW method, it was necessary to provide the welding stand with additional equipment. A novel two-torch set with torches operating in tandem was developed within the experiment. The effectiveness of specimen remelting using a laser and the GTAW method was verified based on macro- and microscopic examinations as well as in X-ray phase analysis and hardness measurements. In addition, the remelting parameters were optimised. The proposed treatment methodology enabled the achieving of the intended result and effective modification of a magnesium alloy surface layer.

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