scholarly journals Study of ph effect on AZ31 magnesium alloy corrosion for using in temporary implants

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Caio A. J. da Silva Da Silva ◽  
Lilian N. M. Braguin ◽  
Larissa O. Berbel ◽  
Bárbara V. G. De Viveiros ◽  
Jesualdo L. Rossi ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Body Fluid ◽  
Ph Effect ◽  
Az31 Alloy ◽  
Corrosion Process ◽  
Az31 Magnesium Alloy ◽  
Nacl Solution ◽  
Agar Gel ◽  
Ph Variation ◽  
Elemental Chemical Analysis

Currently, magnesium alloys are gaining great interest for medical applications due to their degrading properties in the human body ensuring a great biocompatibility. These alloys also provide profitable mechanical properties due similarities with human bone.  However, a difficulty in applying these materials in the biomaterials industries is the corrosion prior to cell healing. The effect of the chemical composition of Mg alloys on their corrosion behavior is well known. In this study, samples of AZ31 magnesium alloy were cut into chips for elemental chemical analysis by neutron activation analysis (NAA). Concentrations of the elements As, La, Mg, Mn, Na, Sb and Zn were determined in the AZ31 alloy. Visualization tests of agar corrosion development in various media, of 0.90% sodium chloride solution (mass), phosphate buffer saline (PBS) and simulated body fluid (SBF) were performed. Visualizations of the effect of agar gel corrosion revealed pH variation during the corrosion process due to the released into the cathode. The highest released of hydroxyl ions occurred in NaCl solution compared to PBS and SBF solutions indicating that NaCl solution was much more aggressive to the alloy compared to the others.

ACCUMULATIVE ROLL BONDING OF AZ31 MAGNESIUM ALLOY

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2833-2939 ◽  
Author(s):  
S. M. FATEMI-VARZANEH ◽  
A. ZAREI-HANZAKI ◽  
M. HAGHSHENAS
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Accumulative Roll Bonding ◽  
Az31 Alloy ◽  
Thickness Reduction ◽  
Az31 Magnesium Alloy ◽  
Total Strain ◽  
Roll Bonding ◽  
Fine Grain

This work conducted to investigate the effects of accumulative roll bonding (ARB) method on achieving the ultra-fine grain microstructure in AZ31 alloy. Accordingly, a number of ARB routes at 400°C, applying thickness reductions per pass of 35%, 55%, and 85% were performed. The results indicate that both the final grain size and the degree of bonding have been dictated by the thickness reduction per pass. The larger pass reductions promote a higher degree of bonding. Increasing the total strain stimulates the formation of a more homogeneous ultra fine grain microstructure.

scholarly journals INFLUENCE OF A PREFABRICATED-CROWN ROLLING PROCESS ON THE CORROSION BEHAVIOUR OF AZ31 MAGNESIUM ALLOY

2021 ◽  
Vol 55 (4) ◽  
Author(s):  
Zhiquan Huang ◽  
Jinchao Zou ◽  
Junpeng Wang ◽  
Yanjie Pei ◽  
Renyao Huang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Plate Thickness ◽  
Az31 Alloy ◽  
Rolling Process ◽  
Charge Transfer Resistance ◽  
Az31 Magnesium Alloy ◽  
Transfer Resistance

The present study aims to investigate the effect of a prefabricated-crown rolling process on the corrosion characteristic of the AZ31 magnesium alloy. Specimens made of the AZ31 alloy were rolled under various crown conditions, and their microstructure evolution and corrosion behavior were analyzed. The corrosion behavior was studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the corrosion-current density of the AZ31 alloy with a side pressure of 37.5 % of the plate thickness of the precast convexity decreased from 3.79 × 10–6 A/cm2 to 1.80 × 10–6 A/cm2, and the difference between the edge and the middle of the AZ31 alloy was shortened from 2.05 × 10–6 A/cm2 to 1.14 × 10–6 A/cm2. The charge-transfer resistance also increased from 507.1 Ω·cm2 to 581.2 Ω·cm2. The improvement in the corrosion resistance is a result of the more stable corrosion products and microstructure refinement formed after the prefabricated-crown rolling process.

Effect of D-fructose on the in-vitro corrosion behavior of AZ31 magnesium alloy in simulated body fluid

2021 ◽  
Vol 66 ◽  
pp. 202-212 ◽  
Author(s):  
Durga Bhakta Pokharel ◽  
Wu Liping ◽  
Junhua Dong ◽  
Xin Wei ◽  
Ini-Ibehe Nabuk Etim ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Simulated Body Fluid ◽  
Corrosion Behavior ◽  
Body Fluid ◽  
Az31 Magnesium Alloy

scholarly journals Determination of the Hot Cracking Tendency of a Twin-Roll Cast AZ31 Magnesium Alloy by Means of Gleeble Tests

2018 ◽  
Vol 918 ◽  
pp. 40-47
Author(s):  
Heike Wemme ◽  
Christina Krbetschek ◽  
Madlen Ullmann ◽  
Anna Freigang ◽  
Stefan Plach ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Az31 Alloy ◽  
Hot Cracking ◽  
Az31 Magnesium Alloy ◽  
Cast Magnesium ◽  
Twin Roll Cast ◽  
Twin Roll ◽  
Cracking Tendency

The knowledge about the formation of hot cracking in magnesium alloys, such as in twin-roll cast magnesium sheets and strips, is fundamental for a good quality of the strips during the further processing by rolling or welding and minimize the reject. Hot cracking often occurs in the so-called mushy zone, when solid phases and melt coexist, at temperatures where the material no longer exhibits ductility. For the evaluation of the hot cracking tendency of an alloy, the width of the HTBR (High-temperature brittleness range) can be used. On the basis of a test on a Gleeble HDS-V40, the HTBR was determined for a twin-roll cast AZ31 magnesium alloy. The transition between ductile forming behaviour and complete brittle reaction of the AZ31 alloy is confirmed by the observation of the fracture surfaces (determination of the fracture type) in the scanning electron microscope (SEM) and is located at 555 °C. The HTBR shows a range 35 K.

Comparison of Different Content of Cd and Sb Element on the Microstructure, Mechanical Properties of As-Cast AZ31 Magnesium Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 197-201
Author(s):  
Xiao Ping Luo ◽  
Lan Ting Xia ◽  
Ming Gang Zhang
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Az31 Alloy ◽  
Hexagonal Structure ◽  
Az31 Magnesium Alloy ◽  
The Matrix ◽  
The Difference ◽  
Significant Addition ◽  
Different Content ◽  
New Phase

The effect of Cd and Sb addition on the microstructural and mechanical properties of as-cast AZ31 alloys was investigated and compared. The results indicate that the difference of Sb and Cd in the microstructure and mechanical properties of as-cast AZ31 magnesium alloy is significant. Addition of 0.15%Sb (mass fraction) to AZ31 alloy can refine the matrix and β-Mg17Al12phase but not form a new phase Mg3Sb2. Oppositely, by addition of 0.3-0.7% Cd to AZ31 alloy, Cd was dissolved into the AZ31 alloy, the phase composition did not change but was refined also. Accordingly, the Cd-refined AZ31 alloy exhibits higher tensile and impact toughness and Brinell hardness properties than the Sb- refined one. The difference of Sb and Cd in the mechanical properties is possibly related to the solid solution of Cd into the matrix and formation of Mg3Sb2which has the same close-packed hexagonal structure as α-Mg.

Surface Modification on Magnesium Alloys by Coating with Magnesium Fluorides

2005 ◽  
Vol 475-479 ◽  
pp. 505-508 ◽  
Author(s):  
T. Ohse ◽  
Harushige Tsubakino ◽  
Atsushi Yamamoto
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Az31 Alloy ◽  
Immersion Test ◽  
Low Ph ◽  
Nacl Solution ◽  
Filiform Corrosion ◽  
A New Technique

A new technique has been developed for improving corrosion resistance on magnesium alloys. Specimens of AZ31 magnesium alloy were dipped into molten salt of NaBF4 at 723 K for various times, and then cooled, rinsed with water, and dried in air. Corrosion resistance in the surface treated specimens was evaluated by salt immersion test using 1 % NaCl solution as a time for occurring filiform corrosion. On an un-treated AZ31 alloy, the time for starting the filiform corrosion was about 1.2 ks, while on the surface treated specimen, the time was prolonged into about 1300 ks. Moreover, the surface treated specimen showed corrosion resistance in low pH solutions, such as 1 % HNO3 and HCl solutions.

Influence of number of ECAP passes on microstructure and mechanical properties of AZ31 magnesium alloy

2012 ◽  
Vol 57 (3) ◽  
pp. 711-717 ◽  
Author(s):  
K. Bryła ◽  
J. Dutkiewicz ◽  
L. Litynska-Dobrzynska ◽  
L.L. Rokhlin ◽  
P. Kurtyka
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Vickers Microhardness ◽  
Az31 Alloy ◽  
Az31 Magnesium Alloy ◽  
Angular Pressing ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron

The aim of this work was to investigate the influence of the number of equal channel angular pressing (ECAP) passes on the microstructure and mechanical properties of AZ31 magnesium alloy. The microstructure after two and four passes of ECAP at 423 and 523 K was investigated by means of optical and transmission electron microscopy. The mechanical properties were carried out using Vickers microhardness measurements and compression test. The grain refinement in AZ31 alloy was obtained using ECAP routes down to 1,5 μm at 423 K. Processes of dynamic recrystallization during ECAP were observed. It was found that a gradual decrease of grain size occurs with the increasing of number of ECAP passes. The grain refinement increases mechanical properties at ambient temperature, such as Vickers microhardness and compression strength proportionally to d-0.5.

scholarly journals Fabrication of Strong and Ductile AZ31 Magnesium Alloy Using High Strain Rate Multiple Forging in a Wide Temperature Range

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 729 ◽  
Author(s):  
Yuanzhi Wu ◽  
Bin Deng ◽  
Tuo Ye ◽  
Zhicheng Nie ◽  
Xiao Liu
Keyword(s):  
Magnesium Alloy ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Az31 Alloy ◽  
Az31 Magnesium Alloy ◽  
Basal Texture ◽  
Texture Characteristic ◽  
Temperature Range ◽  
Grain Sizes

High strain rate multiple forging (HSRMF) was successfully carried out on AZ31 magnesium alloy at a temperature range of 250–400 °C, and the microstructure, texture and mechanical properties were examined. Full recrystallized structure developed at a relatively lower strain due to the twining induced dynamic recrystallization (TDRX) mechanism, which is also responsible for the feasibility of HSRMF deformation at relative low temperature. The average grain sizes of the alloys high strain rate multiple forged (HSRMFed) to the accumulated strain of ∑Δε = 1.32 increased from 7.07 to 9.99 μm as the temperature ranged from 250 to 400 °C, i.e., the grain sizes of the HSRMFed alloy were less sensitive to temperature. The weakened basal texture characteristic of titled or double peak achieved was ascribed to the alteration of forging direction. The HSRMFed alloys demonstrated both excellent strength (UTS > 300 MPa) and good ductility (δ > 20%), which resulted from the combined effects of grain refinement and weakened basal texture. Therefore, HSRMF was an efficient technique to produce strong and ductile wrought AZ31 alloy.

Stress corrosion cracking behavior of micro-arc oxidized AZ31 alloy

2019 ◽  
Vol 234 (8) ◽  
pp. 1640-1652 ◽  
Author(s):  
Xiuli He ◽  
Hongyu Liang ◽  
Zhifeng Yan ◽  
Rui Bai
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Az31 Alloy ◽  
Corrosion Cracking ◽  
Nacl Solution ◽  
Cracking Behavior ◽  
Good Corrosion Resistance ◽  
Mixed Fracture

The stress corrosion cracking behaviors of micro-arc oxidized AZ31 magnesium alloy were studied by using the slow tensile test in air and 3.5 wt.% NaCl solution. Results showed that compared with the substrate, the stress corrosion cracking susceptibility of the micro-arc oxidized specimens was obvious improved apparently in 3.5 wt.% NaCl solution, due to the good corrosion resistance of the specimens after micro-arc oxidized coating treatment. In addition, regardless of the micro-arc oxidized treatment, it was the mixed fracture in air and the cleavage fracture in 3.5 wt.% NaCl solution. The micro-arc oxidized coating had no direct effect on the fracture mechanism of the alloy. It was closely related to the nature of the material and the environment of the material servicing.

Sign in / Sign up

Export Citation Format

Share Document