scholarly journals Fibre Laser Cutting and Chemical Etching of AZ31 for Manufacturing Biodegradable Stents

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ali Gökhan Demir ◽  
Barbara Previtali ◽  
Carlo Alberto Biffi
Keyword(s):  
Magnesium Alloy ◽  
Chemical Etching ◽  
Fibre Laser ◽  
Nanosecond Laser ◽  
Intrinsic Dissolution ◽  
Biodegradable Stents ◽  
Innovative Solutions ◽  
Material Choice ◽  
Cardiovascular Pathologies ◽  
Reactive Gas

The use of magnesium-alloy stents shows promise as a less intrusive solution for the treatment of cardiovascular pathologies as a result of the high biocompatibility of the material and its intrinsic dissolution in body fluids. However, in addition to requiring innovative solutions in material choice and design, these stents also require a greater understanding of the manufacturing process to achieve the desired quality with improved productivity. The present study demonstrates the manufacturing steps for the realisation of biodegradable stents in AZ31 magnesium alloy. These steps include laser microcutting with a Q-switched fibre laser for the generation of the stent mesh and subsequent chemical etching for the cleaning of kerf and surface finish. Specifically, for the laser microcutting step, inert and reactive gas cutting conditions were compared. The effect of chemical etching on the reduction in material thickness, as well as on spatter removal, was also evaluated. Prototype stents were produced, and the material composition and surface quality were characterised. The potentialities of combining nanosecond laser microcutting and chemical etching are shown and discussed.

scholarly journals The Effect of Pulsed Nanosecond Laser Irradiation on the Corrosion Resistance of Mg–Al–Zn Magnesium Alloy

2020 ◽  
Vol 11 (3) ◽  
pp. 547-551
Author(s):  
S. A. Bozhko ◽  
S. S. Manokhin ◽  
A. Yu. Tokmacheva-Kolobova ◽  
Yu. Yu. Karlagina ◽  
A. E. Ligachev
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Laser Irradiation ◽  
Nanosecond Laser

WATER DROPLET EVAPORATION IN A CHAMBER ISOLATED FROM THE EXTERNAL ENVIRONMENT

2021 ◽  
Vol 7 (1) ◽  
pp. 26-43
Author(s):  
Ksenia A. BATISHCHEVA ◽  
Yuliya N. Vympina ◽  
Evgeniya G. ORLOVA
Keyword(s):  
Magnesium Alloy ◽  
Self Assembly ◽  
Droplet Evaporation ◽  
The Self ◽  
Homogeneous Layer ◽  
Nanosecond Laser ◽  
Alloy Sample ◽  
Textured Surface ◽  
Colloidal Solutions ◽  
Aluminum Magnesium Alloy

Establishing the characteristics of the self-assembly of micron and sub-micron particles when colloidal solution droplets evaporate from solid surfaces is an urgent problem. This is explained by the possibility of using these structures obtained by droplet technologies to create and optimize the production of direct and indirect liquid cooling devices, electronic and sensor working boards, current-conducting coatings, optical crystals, and chemo sensors. The method used in this study for processing of metals and alloys by laser radiation is prospective for controlling the processes at the liquid/gas/solid interface. This article aims to analyze the effect of laser processing of the widely used in the industry aluminum-magnesium alloy on the formation of a layer of particles during the droplet evaporation of colloidal solutions. The samples’ surfaces were processed by two methods: polished by tumbling and nanosecond laser pulses. The geometric parameters of the droplets of colloidal solutions evaporating from the samples’ surfaces were determined by the shadow method. To process the obtained shadow images, the Young — Laplace method was used. Using a scanning electron microscope, the authors have received the images of the particles’ layers formed due to the droplet evaporation of colloidal solutions. The experimental studies reveal the effect of texture formed on aluminum-magnesium alloy sample on the morphology of the layer of polystyrene nanoparticles during the droplet evaporation of colloidal solutions. Due to the self-assembly of particles, solid ring-like sediments are formed, which are elongated under the action of the capillary force parallel to the motion vector of the laser beam (when creating the texture). When the solvent evaporated from the solution droplet on the textured surface, in addition to the rings, a homogeneous layer of polystyrene particles was formed. This refers to the droplet evaporation of the solution. The results show that with an increase in the concentration of particles in the solution, the sizes of radial cracks on the rings formed due to particle deposition increase. There were no cracks on the rings at a relatively low volume concentration of particles.

Computational Modeling of the Mechanical Performance of a Magnesium Stent Undergoing Uniform and Pitting Corrosion in a Remodeling Artery

2017 ◽  
Vol 11 (2) ◽  
Author(s):  
Enda L. Boland ◽  
James A. Grogan ◽  
Peter E. McHugh
Keyword(s):  
Magnesium Alloy ◽  
Computational Modeling ◽  
Pitting Corrosion ◽  
Mechanical Performance ◽  
Formation Rate ◽  
The Body ◽  
Neointimal Formation ◽  
Modeling Framework ◽  
Element Analysis ◽  
Biodegradable Stents

Coronary stents made from degradable biomaterials such as magnesium alloy are an emerging technology in the treatment of coronary artery disease. Biodegradable stents provide mechanical support to the artery during the initial scaffolding period after which the artery will have remodeled. The subsequent resorption of the stent biomaterial by the body has potential to reduce the risk associated with long-term placement of these devices, such as in-stent restenosis, late stent thrombosis, and fatigue fracture. Computational modeling such as finite-element analysis has proven to be an extremely useful tool in the continued design and development of these medical devices. What is lacking in computational modeling literature is the representation of the active response of the arterial tissue in the weeks and months following stent implantation, i.e., neointimal remodeling. The phenomenon of neointimal remodeling is particularly interesting and significant in the case of biodegradable stents, when both stent degradation and neointimal remodeling can occur simultaneously, presenting the possibility of a mechanical interaction and transfer of load between the degrading stent and the remodeling artery. In this paper, a computational modeling framework is developed that combines magnesium alloy degradation and neointimal remodeling, which is capable of simulating both uniform (best case) and localized pitting (realistic) stent corrosion in a remodeling artery. The framework is used to evaluate the effects of the neointima on the mechanics of the stent, when the stent is undergoing uniform or pitting corrosion, and to assess the effects of the neointimal formation rate relative to the overall stent degradation rate (for both uniform and pitting conditions).

Biomimetic hydrophobic surface fabricated by chemical etching method from hierarchically structured magnesium alloy substrate

2013 ◽  
Vol 280 ◽  
pp. 845-849 ◽  
Author(s):  
Yan Liu ◽  
Xiaoming Yin ◽  
Jijia Zhang ◽  
Yaming Wang ◽  
Zhiwu Han ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Chemical Etching ◽  
Hydrophobic Surface ◽  
Alloy Substrate ◽  
Etching Method

scholarly journals Forming of magnesium alloy microtubes in the fabrication of biodegradable stents

2014 ◽  
Vol 24 (5) ◽  
pp. 500-506 ◽  
Author(s):  
Lixiao Wang ◽  
Gang Fang ◽  
Lingyun Qian ◽  
Sander Leeflang ◽  
Jurek Duszczyk ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Biodegradable Stents

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.

Wavelength-switchable C-band erbium-doped fibre laser incorporating all-fibre Fabry–Perot interferometer fabricated by chemical etching

2017 ◽  
Vol 65 (7) ◽  
pp. 818-824 ◽  
Author(s):  
Wei He ◽  
Lianqing Zhu ◽  
Mingli Dong ◽  
Xiaoping Lou ◽  
Fei Luo
Keyword(s):  
Chemical Etching ◽  
Fibre Laser ◽  
Erbium Doped ◽  
Fabry Perot

scholarly journals Ytterbium-doped fibre femtosecond laser offers robust design with deep and precise microsurgery

2019 ◽  
Author(s):  
MB Harreguy ◽  
V Marfil ◽  
CV Gabel ◽  
SH Chung ◽  
G Haspel
Keyword(s):  
Solid State ◽  
Femtosecond Laser ◽  
Laser Source ◽  
Fibre Laser ◽  
Nanosecond Laser ◽  
Solid State Lasers ◽  
C Elegans ◽  
High Standards ◽  
Maintenance Requirements

AbstractLaser microsurgery is a powerful tool for neurobiology used to ablate cells and sever neurites in-vivo. We compare a relatively new laser source to two well-established designs. Rare-earth-doped mode-locked fibre laser that produce high power pulsed radiation recently gained popularity for industrial uses. Such systems are manufactured at high standards of robustness and low maintenance requirements typical of solid-state lasers. We demonstrate that an Ytterbium-doped fibre femtosecond laser is comparable in precision to other femtosecond lasers, but with added reliability. It is more precise and can lesion deeper in tissue than a solid-state nanosecond laser. These advantages are not specific to the model system ablated for our demonstration, namely neurites in the nematode C. elegans, but are applicable to other systems and transparent tissue where a precise submicron resolution dissection is required.

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