Corrosion Fatigue Behaviour of a Common AZ91D Magnesium Alloy in Modified Simulated Body Fluid

2014 ◽  
Vol 891-892 ◽  
pp. 267-272 ◽  
Author(s):  
Sajjad Jafari ◽  
R.K. Singh Raman
Keyword(s):  
Magnesium Alloy ◽  
Simulated Body Fluid ◽  
Magnesium Alloys ◽  
Corrosion Fatigue ◽  
Body Fluid ◽  
Fatigue Behaviour ◽  
New Paradigm ◽  
Metallic Implants ◽  
Alloy Az91d ◽  
Cast Magnesium

Use of Magnesium alloys as body implants are breaking into a new paradigm of biomedical engineering as they are biocompatible, biodegradable and have mechanical properties close to that of bone. Even though corrosion fatigue (CF) and stress corrosion cracking (SCC) failures are among the most common concerns for metallic implants, CF behaviour of magnesium alloys in physiological environments has received little attention. This article reports the CF results of a common cast magnesium alloy (AZ91D) in modified simulated body fluid (m-SBF). Results showed that there was a remarkable difference in fatigue strength of Mg alloys when tests were performed in m-SBF.

scholarly journals Tensile Properties of Die-Cast Magnesium Alloy AZ91D at High Strain Rates in the Range between 300 s-1 and 1500 s-1

2010 ◽  
Vol 24-25 ◽  
pp. 325-330 ◽  
Author(s):  
Iram Raza Ahmad ◽  
Dong Wei Shu
Keyword(s):  
Tensile Strength ◽  
Magnesium Alloy ◽  
Strain Rate ◽  
Magnesium Alloys ◽  
Dynamic Behaviour ◽  
High Strain ◽  
Strain Rates ◽  
Alloy Az91d ◽  
Cast Magnesium Alloy ◽  
Cast Magnesium

Magnesium alloys have been increasingly used in the automobile, aerospace and communication industries due to their low density, high strength to weight ratio, good impact resistance and castability. Magnesium alloys, previously not used in load bearing components and structural parts are strongly being considered for use in such applications. Impact events in vehicles and airplanes as well as developments in weaponry and high speed metal working are all characterized by high rates of loading. Understanding of the dynamic behaviour of materials is critical for proper design and use in different applications. In the current study, a cast magnesium alloy AZ91D has been investigated at quasi-static and higher strain rates in the range between 300 s-1 and 1500 s-1. The INSTRON machine was used to perform the quasi-static tests. High strain rate tests have been performed using the Split Hopkinson Tensile Bar (SHTB), a very useful and widely used tool to study the dynamic behaviour of variety of engineering materials. The results of a tensile testing indicate that the tensile properties including yield strength (YS), ultimate tensile strength (UTS) and the elongation at fracture (Ef) are affected by the strain rate variation. Higher stresses are associated with higher strain rates. The alloy AZ91D displays approximately 45% higher tensile stresses at an average strain rate of approximately 1215/s than at quasi-static strain rate. The dependence of the yield stress and tensile strength on the strain rate in the range of high strain rate above 1000 s-1 is larger than that at lower strain rates. The alloy AZ91D is observed to be more strain rate sensitive for strain rate higher than 1000 s-1. A decrease in the strain rate sensitivity is also observed with the increasing strain in the specimen. It is observed that the hardening behaviour of the alloy is affected with increasing the strain rate. At high strain rates, the fracture of magnesium alloy AZ91D tends to transit from ductile to brittle.

Corrosion Behaviors in Simulated Body Fluid for TiO2 Films Deposited on AZ31 Magnesium Alloys by Magnetron Sputtering

2012 ◽  
Vol 217-219 ◽  
pp. 1053-1056
Author(s):  
Xiang Rong Zhu ◽  
Zhong Ping Xu ◽  
Nai Ci Bing ◽  
Qiu Rong Chen
Keyword(s):  
Magnesium Alloy ◽  
Simulated Body Fluid ◽  
Magnetron Sputtering ◽  
Magnesium Alloys ◽  
Body Fluid ◽  
Az31 Magnesium Alloy ◽  
Tio2 Films ◽  
Tio2 Layer ◽  
Corrosion Properties ◽  
Corrosion Behaviors

TiO2 films were deposited on AZ31 magnesium alloy substrates by r.f. magnetron sputtering. The corrosion behaviors in simulated body fluid (SBF) of the film samples were investigated and compared to the bare AZ31 magnesium alloy. After 3 days’ corrosion in SBF, only part of the TiO2 layer suffered from corrosion and the substrate was prevented from corrosion. In contrast, the bare magnesium alloy suffered from severe corrosion. After 10 days’ corrosion, the TiO2 layer was penetrated and the substrates still did not suffer from corrosion. After 15 days’ corrosion, besides TiO2 layer, the substrate suffered from corrosion to some degree. The depth of the corrosion layer is about 6 m, which is far lower than that of bare magnesium alloy, 40 m. The results show that TiO2 films effectively improve the corrosion properties of magnesium alloys.

Corrosion fatigue of a magnesium alloy in modified simulated body fluid

2015 ◽  
Vol 137 ◽  
pp. 2-11 ◽  
Author(s):  
Sajjad Jafari ◽  
R.K. Singh Raman ◽  
Chris H.J. Davies
Keyword(s):  
Magnesium Alloy ◽  
Simulated Body Fluid ◽  
Corrosion Fatigue ◽  
Body Fluid

Control of Degradation of Biocompatible Magnesium in a Pseudo-Physiological Environment by a Ceramic Like Anodized Coating

2007 ◽  
Vol 29-30 ◽  
pp. 95-98 ◽  
Author(s):  
Guang Ling Song
Keyword(s):  
Magnesium Alloy ◽  
Simulated Body Fluid ◽  
Hydrogen Evolution ◽  
Magnesium Alloys ◽  
Body Fluid ◽  
Degradation Rate ◽  
Biodegradable Implant ◽  
New Approach ◽  
Biodegradation Process

Magnesium alloys are potential biodegradable implant materials. However, magnesium alloys normally corrode rapidly in the in-vivo fluid, resulting in subcutaneous gas bubbles and alkalisation of the in-vivo solution. The paper presents a new approach to control the degradation rate of magnesium in a simulated body fluid (SBF) through employing a recently developed anodising technique. It was found that the ceramic like anodised coating formed on the surface of magnesium can effectively slow down the biodegradation process and hence result in slow hydrogen evolution and solution alkalisation processes. The results imply that an anodised magnesium alloy may be successfully used as a biodegradable implant material.

Sign in / Sign up

Export Citation Format

Share Document