Microstructure Evolution during Mechanical Alloying of a Biodegradable Magnesium Alloy (original) (raw)
Related papers
Mechanical Alloying Process Applied for Obtaining a New Biodegradable Mg-xZn-Zr-Ca Alloy
Metals
The aim of the present paper is to apply the mechanical alloying process to obtain from powder components a new biodegradable Mg-based alloy powder from the system Mg-xZn-Zr-Ca, with high biomechanical and biochemical performance. Various processing parameters for mechanical alloying have been experimented with the ultimate goal to establish an efficient processing route for the production of small biodegradable parts for the medical domain. It has been observed that for the same milling parameters, the composition of the powders has influenced the powder size and shape. On the other hand, for the same composition, the highest experimented milling speed and time conduct to finer powder particles, almost round-shaped, without pores or various inclusions. The most uniform size has been obtained for the powder sample with 10 wt.%Zn. These powders were finally processed by selective laser melting, an additive manufacturing technology, to obtain a homogeneous experimental sample, without...
Microstructure analysis of the modified casting magnesium alloys after heat and laser treatment
2009
AbstrAct Purpose: In this paper there is presented the structure of the modeling cast magnesium alloy EN-MCMgAl6Zn1 as cast state, after heat treatment and laser treatment. Design/methodology/approach: The presented results concern X-ray qualitative and quantitative microanalysis as well as qualitative and quantitative X-ray diffraction method, light and scanning microscope. A casting cycle of alloys has been carried out in an induction crucible furnace using a protective salt bath Flux 12 equipped with two ceramic filters at the melting temperature of 750±10ºC, suitable for the manufactured material. The heat treatment involve the solution heat treatment (warming material in temperature 375° C by 3 hour, it elevation temperature to 430° C, warming by 10 hours) and cooling in different cooling mediums as well water, air and furnace. Laser surface melting was carried out with a high power diode laser (HDPL). Findings: The results of the metallographic examinations confirm the fact that the magnesium cast alloy MCMgAl6Zn1 is characterized by a microstructure of the α solid solution constituting the alloy matrix as well as the ß -Mg 17 Al 12 discontinuous intermetallic phase in the forms of plates located mostly at grain boundaries. The results indicate that laser-melted layer contains the fine dendrites. The substrate grains are significantly coarses than in the laser surface remelting zone. Research limitations/implications: According to the alloys characteristic, the applied cooling rate and alloy additions seems to be a good compromise for mechanical properties and microstructures, nevertheless further tests should be carried out in order to examine different cooling rates and parameters of solution treatment process and aging process. This investigation presents different speed rates feed by one process laser power and in this research was used one powder with the particle size over 5µm. Practical implications: This work helps to use the new developed laser treatment technique for alloying and remelting of magnesium cast alloys for new application. Originality/value: The originality of this work is based on applying of High Power Diode Laser for improvement of properties of the magnesium alloys.
2020
Magnesium (Mg) alloys have promising potentials for lightweight and biomedical applications. Although there has been a recent interest in producing Mg alloys (including AZ, ZK and WE series) using additive manufacturing (AM), the process-structure-corrosion properties relationships in AM Mg alloys are yet to be understood. Herein, the production of Mg alloy WE43 was achieved by selective laser melting (SLM). The alloy was investigated after SLM, hot isostatic pressing (HIP) as well as an additional solutionising heat treatment. Specimens were carefully characterised, whilst assessed and contrast relative to the conventionally cast alloy counterpart. Characterisation included detailed microstructural analysis employing analytical transmission electron microscopy, X-ray mapping, and electron backscatter diffraction, which revealed the SLM prepared specimens possess a unique microstructure comprising fine grains growing with a strong [0001] texture along the building direction. The SLM...
Laser Powder Bed Fusion Applied to a New Biodegradable Mg-Zn-Zr-Ca Alloy
Materials, 2022
The aim of the present paper is to apply the laser powder bed fusion process to a new biodegradable Mg-Zn-Zr-Ca alloy powder prepared via a mechanical alloying method from powder pure components. This additive manufacturing method is expected to allow for the obtaining of high biomechanical and biochemical performance. Various processing parameters for laser powder bed fusion are tested, with a special focus on laser energy density—E [J/mm3]—which is calculated for all experiment variants, and which represents an important processing parameter, dependent upon all the rest. The goal of all the trials is to find the most efficient schema for the production of small biodegradable parts for the medical domain, meaning the selection of optimal processing parameters. An important observation is that the most robust and homogeneous samples without cracks are obtained for lower values of the E, around 100 J/mm3. Thus, the most performant samples are analyzed by scanning electron microscopy,...
Journal of Biomaterials and Nanobiotechnology, 2018
Biomaterial powders are in high development due to expansion of additive manufacturing (AM) processes. Selective laser melting (SLM) is a particular AM technology, which completely melts a powder bed layer by laser beam. Investigations of appropriated physical properties of feedstock (powder alloy) were the aim of this study. Cobalt-chromium-molybdenum (Co-Cr-Mo) alloy was used to overview of gas-atomized powder properties in different granulometric ranges (D1 12-19 μm, D2 20-46 μm and D3 76-106 μm), as their: physical, chemical properties and thermal analysis. SLM manufactured standard tensile specimens of usually granulometric range powder size provided mechanical, chemical and thermal properties of biocompatible Co-Cr-Mo alloy. The physical properties showed that powders in the range of 20 to 50 µm provide a better flow ability and packed density, which are relevant characteristics to SLM processing. Manufacturing by SLM process provided suitable mechanical properties in the health area, as well as, maintained the biocompatible properties of the Co-Cr-Mo alloy.
Effect of Ca and Zn additions on the mechanical properties of Mg produced by powder metallurgy
AIP Conference Proceedings, 2017
Magnesium and its alloys are among important research topics in view of their excellent biocompatibility.In this study mechanical and microstructure properties of hot sintered Mg-Zn-Ca alloys were studied.The effects of the addition of different amounts Ca and Zn were added to the base material has been processed by powder metallurgy method.resulting microstructures densities and compression test behaviors of the Mg-based alloys were studied.Visual inspection using SEM (Scanning Electron Microscope) analyses indicates that the microstructure of the composite is also greatly effected by these parameters. In addition, EDS (Energy Dispersive X-Ray Spectroscopy) analyses were performed for reliable determination of the chemical composition.
Biodegradable Magnesium Alloys for Personalised Temporary Implants
Journal of Functional Biomaterials
The objective of this experimental work was to examine and characterise the route for obtaining demonstrative temporary biodegradable personalised implants from the Mg alloy Mg-10Zn-0.5Zr-0.8Ca (wt.%). This studied Mg alloy was obtained in its powder state using the mechanical alloying method, with shape and size characteristics suitable for ensuing 3D additive manufacturing using the SLM (selective laser melting) procedure. The SLM procedure was applied to various processing parameters. All obtained samples were characterised microstructurally (using XRD—X-ray diffraction, and SEM—scanning electron microscopy); mechanically, by applying a compression test; and, finally, from a corrosion resistance viewpoint. Using the optimal test processing parameters, a few demonstrative temporary implants of small dimensions were made via the SLM method. Our conclusion is that mechanical alloying combined with SLM processing has good potential to manage 3D additive manufacturing for personalised...
Development of Mg-Alloy by Powder Metallurgy Method and Its Characterization
Powder Metallurgy and Metal Ceramics, 2019
In the present research work, an attempt has been made to make Mg-alloy specimen by powder metallurgy. Due to sensitivity of the material, a proper selection of sintering atmosphere has been made. Mg powder along with other powders has been blended with a high energy ball mill. In this work, the effect of input parameters, such as compaction pressure, sintering temperature and sintering time was investigated on porosity, microhardness and dimensional change. The compaction pressure and sintering temperature play a significant role in the porosity and microhardness. Increasing the compaction pressure plays a positive role in the microhardness. The maximum value of the porosity in the present work was up to 37.41%. The dimensional expansion after sintering varies from 2 to 4.3%. The results of the porosity and microhardness were verified by scanning electron microscopy and X-ray diffraction.
Synthesis of Magnesium-Based Alloys by Mechanical Alloying for Implant Applications
Coatings
The biocompatibility and biodegradability of magnesium (Mg), along with its lightness, make magnesium-based materials promising for use in the biomedical industry. In this work, ternary Mg–Zn–Ca alloys were manufactured for biomedical applications using mechanical alloying (MA). The objective of this work was to study the effect of milling time on the produced ternary alloys Mg65–Zn30–Ca5 and Mg70–Zn25–Ca5 (percentages by weight), the degradation of the alloys in synthetic human fluids, and their generated cytotoxicity. The Mg-based alloys were synthesized in a planetary ball mill under an argon atmosphere using stainless-steel containers and balls with a milling regimen of 400 rpm for 2, 5, 10, 15, and 20 h. The powders obtained after MA were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), which verified that ternary Mg–Zn–Ca alloys can be obtained using MA. The XRD refinement analysis of the samples showed the presence of a MgZn intermetallic phase...
Microstructure and mechanical properties of extruded profiles made from pure magnesium powders
Kovové materiály, 2020
Magnesium-based biomaterials are good candidates as a new generation of biodegradable metals since magnesium (Mg) can dissolve in body fluid. Therefore, implanted Mg can degrade during the healing process, and if the degradation rate is controlled no debris after completion of healing is expected. Besides its biocompatibility, inherent mechanical properties of Mg are very similar to those of human bone. This paper is focused on the possibility to prepare the pure Mg material from powders with further intention to use it as a biodegradable implant. Powders were consolidated via cold compaction to prepare the extrusion billets which were subsequently directly extruded to final profiles at a controlled temperature to avoid the formation of the thick oxide layer. The microstructure is revealed through SEM, SEM-EBSD, TEM, and HRTEM and mechanical properties are determined via a uniaxial tensile test. Results are compared with Mg ingot and WE43 alloy, which is commercially used for biodegradable (biocompatible) material.