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Structure and compression strength characteristics of the sintered Mg–Zn–Ca–Gd alloy for medical applications

Lesz S., Kraczla J., Nowosielski R.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 4

1288--1299

EN

Magnesium-based materials have promising mechanical properties and potential to serve as implants for loadbearing temporary applications. The main concern about such implants is their strength and resistance for the acting forces. In this investigation, magnesium-based biodegradable Mg65Zn30Ca4Gd1 alloy prepared by combination of innovative Mechanical Alloying (MA) and Spark Plasma Sintering (SPS) methods, was studied for the structure and mechanical properties. Structural studies were performed using X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). XRD studies were conducted to gain an overview of the phase composition in powdered and sintered samples. The energy dispersive spectroscopy (EDS) additionally determine the chemical composition of the samples. SEM observations were used to examine the morphology of the sinters on the fractured surface after the compressive tests. Mechanical properties of the Mg65Zn30Ca4Gd1 alloy were examined by compressive tests, to determine the compressive strength and Young's modulus of the samples at room temperature. The paper provides information about the density and porosity of the Mg-based alloy and additionally its corrosion resistance. Moreover the work shows advantages and possibilities of forming multi-compound, morphologically homogeneous alloys with high mechanical properties in the powder metallurgy processes.

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Preparation and glass-forming ability of Mg-based bulk amorphous alloys

Babilas R., Zajączkowski A., Głuchowski W., Nowosielski R.

Archives of Materials Science and Engineering

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2013

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Vol. 62, nr 2

78--86

EN

Purpose: The work presents preparation methods, structure characterization and glass-forming analysis of Mg-based bulk metallic glasses in as-cast state. Design/methodology/approach: The studies were performed on Mg60Cu30Y10 and Mg60Cu29Y10Si1 glassy alloys in the form of plates and rods. The amorphous structure of tested samples was examined by X-ray diffraction (XRD). The thermal properties associated with solidus and liquidus temperature of master alloys were measured using the differential thermal analysis (DTA). The crystallization behavior of the studied plates and rods was also examined by differential scanning calorimetry (DSC). The fracture morphology of the rods in as-cast state was analyzed using the scanning electron microscopy (SEM). Findings: The X-ray diffraction investigations revealed that the tested samples with different thickness and shape were amorphous. The single exothermic peaks describing crystallization process of studied alloys were observed for all examined samples with different thickness. The endothermic and exothermic peaks observed on DTA curves of master alloys allowed to determine the solidus and liquidus temperatures. The characteristics of the fractured surfaces showed different zones, which might correspond with different amorphous structures. The changes of glass transition and crystallization temperatures as a function of sample thickness were stated. Practical implications: The pressure die casting method are useful technique to fabricate bulk amorphous materials in the form of plates and rods. Proposed casting technology could open new possibilities to easier preparation of Mg-based nanostructured materials and forming their properties that is essential for further applications. Originality/value: The Mg-based bulk amorphous alloys are regarded as promising engineering materials with high strength, low density and good corrosion resistance in contrast to the crystalline alloys, due to their different atomic configurations

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Electronic and electrochemical properties of Mg2Ni alloy doped by Pd atoms

Szajek A., Okońska I., Jurczyk M.

Materials Science Poland

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2007

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Vol. 25, No. 4

1251--1257

EN

The structure and electrochemical properties of nanocrystalline Mg2Ni and Mg2Ni/Pd nanocomposite have been studied. The materials were prepared by mechanical alloying. In nanocrystalline Mg2Ni powder, discharge capacities up to 100 mAźhźg-1 were measured. It was found that mechanically coated Mgbased alloys with palladium have effectively reduced the degradation rate of the studied electrode materials. Finally, the properties of nanocrystalline alloys and their nanocomposites were compared to those of microcrystalline samples. The electronic structure was studied by ab initio calculations, which showed that the 3b positions in the unit cell are preferred by the Pd impurities.