scholarly journals Mg-Based Composites for Biomedical Applications

2021 ◽  
Author(s):  
Moara Marques de Castro ◽  
Débora Ribeiro Lopes ◽  
Leonardo Viana Dias
Keyword(s):  
Metallic Matrix ◽  
Stress Shielding ◽  
Orthopedic Implants ◽  
Critical Parameters ◽  
Major Influence ◽  
Processing Route ◽  
Corrosion Properties ◽  
Bioactive Ceramics ◽  
Degradation Rates ◽  
Mechanical And Corrosion Properties

Magnesium (Mg) is a promising material for producing temporary orthopedic implants, since it is a biodegradable and biocompatible metal which density is very similar to that of the bones. Another benefit is the small strength mismatch when compared to other biocompatible metals, what alleviates stress-shielding effects between bone and the implant. To take advantage of the best materials properties, it is possible to combine magnesium with bioactive ceramics and tailor composites for medical applications with improved biocompatibility, controllable degradation rates and the necessary mechanical properties. To properly insert bioactive reinforcement into the metallic matrix, the fabrication of these composites usually involves at least one high temperature step, as casting or sintering. Yet, recent papers report the development of Mg-based composites at room temperature using severe plastic deformation. This chapter goes through the available data over the development of Mg-composites reinforced with bioactive ceramics, presenting the latest findings on the topic. This overview aims to identify the major influence of the processing route on matrix refinement and reinforcement dispersion, which are critical parameters to determine mechanical and corrosion properties of biodegradable Mg-based composites.

scholarly journals Mechanical and Corrosion Properties of Mg-Based Alloys with Gd Addition

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1775 ◽  
Author(s):  
Aneta Kania ◽  
Ryszard Nowosielski ◽  
Agnieszka Gawlas-Mucha ◽  
Rafał Babilas
Keyword(s):  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Orthopedic Implants ◽  
Corrosion Current ◽  
Medical Application ◽  
Open Circuit ◽  
Dendritic Microstructure ◽  
Corrosion Properties ◽  
Electrochemical Parameters ◽  
Mechanical And Corrosion Properties

Magnesium alloys with rare earth metals are very attractive materials for medical application because of satisfactory mechanical properties. Nevertheless, low corrosion resistance is an obstacle in the use of Mg alloys as resorbable orthopedic implants. The paper presents results of mechanical and corrosion properties of MgCa5-xZn1Gdx (x = 1, 2, and 3 wt. %) alloys. Based on the microscopic observations it was stated that the studied alloys show a dendritic microstructure with interdendritic solute rich regions. The phase analysis reveals an occurrence of α-Mg and Mg2Ca, Ca2Mg6Zn3 phases that are thermodynamic predictions, and stated Mg26Zn59Gd7 phases in MgCa5-xZn1Gdx (x = 1, 2, and 3 wt. %) alloys. The Mg26Zn59Gd7 phases are visible as lamellar precipitations along interdendritic regions. It was confirmed that an increase of Gd content from 1 to 3 wt. % improves ultimate tensile (Rm; from 74 to 89 MPa) and compressive strength (Rc; from 184 to 221 MPa). Moreover, the studied alloys are active in Ringer’s solution. They are characterized by an increase of corrosion potential (Ecorr) of about 150 mV in comparison with values of open circuit potential (EOCP). The best electrochemical parameters (e.g., corrosion current density, icorr, polarization resistance, Rp, and Ecorr) were obtained for the MgCa3Zn1Gd2 alloy.

scholarly journals Effect of Heat Treatment on the Mechanical and Corrosion Properties of Mg–Zn–Ga Biodegradable Mg Alloys

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7847
Author(s):  
Viacheslav Bazhenov ◽  
Anastasia Lyskovich ◽  
Anna Li ◽  
Vasily Bautin ◽  
Alexander Komissarov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Corrosion Rate ◽  
Orthopedic Implants ◽  
Mg Alloys ◽  
Medical Implants ◽  
Corrosion Properties ◽  
Treatment Regimens ◽  
Mechanical And Corrosion Properties ◽  
Potential Use

Mg alloys have mechanical properties similar to those of human bones, and have been studied extensively because of their potential use in biodegradable medical implants. In this study, the influence of different heat treatment regimens on the microstructure and mechanical and corrosion properties of biodegradable Mg–Zn–Ga alloys was investigated, because Ga is effective in the treatment of disorders associated with accelerated bone loss. Solid–solution heat treatment (SSHT) enhanced the mechanical properties of these alloys, and a low corrosion rate in Hanks’ solution was achieved because of the decrease in the cathodic-phase content after SSHT. Thus, the Mg–4 wt.% Zn–4 wt.% Ga–0.5 wt.% Y alloy after 18 h of SSHT at 350 °C (ultimate tensile strength: 207 MPa; yield strength: 97 MPa; elongation at fracture: 7.5%; corrosion rate: 0.27 mm/year) was recommended for low-loaded orthopedic implants.

Surface Modification of Biodegradable Magnesium-Calcium Implants by Burnishing

2011 ◽  
Author(s):  
M. Salahshoor ◽  
Y. B. Guo
Keyword(s):  
Surface Modification ◽  
Surface Integrity ◽  
Stress Shielding ◽  
Orthopedic Implants ◽  
Cnc Machining ◽  
Metallic Implants ◽  
Surface Residual Stresses ◽  
Degradation Rates ◽  
Wide Range ◽  
Surface Modification Techniques

Magnesium-Calcium (MgCa) alloys have shown very promising potential to make biodegradable metallic orthopedic implants. Biodegradable metallic implants relieve the need for second surgery and avoid stress shielding common with permanent metallic implants. Moreover, they provide enough strength in load carrying orthopedic applications as opposed to polymeric counterparts. High degradation rate of these alloys is the pressing issue resulting in subcutaneous hydrogen bubbles and high pH values and ultimately imbalance in physiological reactions. Surface modification techniques has been implemented to enhance the biocompatibility of these alloys by matching their corrosion rate with bone healing rate and absorption rate of corrosion by-products. Low plasticity burnishing (LPB) is a novel technique that makes wide range of surface integrity characteristics and consequently corrosion rates attainable. This is instrumental in developing proper degradation rates with respect to local healing and absorptions rates present in each application. Besides, LPB can be applied on already available CNC machining centers and in that sense is very flexible. Hence, studying the effects of LPB process parameters on surface integrity is important. In this paper, effects of burnishing passes and their pattern on surface topography, surface roughness, surface/subsurface microhardness, microstructure, and surface residual stresses of MgCa0.8 (wt%) implants are investigated.

On the defects of enamel coatings

2019 ◽  
pp. 145-150
Author(s):  
T. O. Soshina ◽  
V. R. Mukhamadyarovа
Keyword(s):  
Heat Treatment ◽  
Surface Tension ◽  
Electron Microscope ◽  
Enamel Coating ◽  
Surface Defects ◽  
Linear Expansion ◽  
Corrosion Properties ◽  
Treatment Conditions ◽  
Mechanical And Corrosion Properties ◽  
Coefficient Of Linear Expansion

The defects destroy the integrity of the enamel, and the paper examines the influence of the physical-mechanical and corrosion properties of frits and heat treatment on the defectiveness of the enamel coating. The surface defects were scanned by electron microscope. It has been established that the defectiveness of enamel coatings depends on the melting index, temperature coefficient of linear expansion, surface tension of the frits, and heat treatment conditions. When burning rate of the enamel coating decreases, the fine-meshed structure of the enamel changes, and the size of the defects decreases.

scholarly journals Microstructure and mechanical and corrosion properties of hot-extruded Mg–Zn–Ca–(Mn) biodegradable alloys

2020 ◽  
Author(s):  
V.E. Bazhenov ◽  
A.V. Li ◽  
A.A. Komissarov ◽  
A.V. Koltygin ◽  
S.A. Tavolzhanskii ◽  
...  
Keyword(s):  
Corrosion Properties ◽  
Mechanical And Corrosion Properties

Spark plasma sintering of Ti6Al4V metal matrix composites: Microstructure, mechanical and corrosion properties

2021 ◽  
Vol 865 ◽  
pp. 158875
Author(s):  
Neera Singh ◽  
Raghunandan Ummethala ◽  
Phani Shashanka Karamched ◽  
Rathinavelu Sokkalingam ◽  
Vasanth Gopal ◽  
...  
Keyword(s):  
Metal Matrix Composites ◽  
Spark Plasma Sintering ◽  
Metal Matrix ◽  
Matrix Composites ◽  
Corrosion Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Mechanical And Corrosion Properties
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