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1

Properties of Biodegradable Alloys Usable for Medical Purposes

100%

Kubásek J., Vojtěch D., Čapek J.

Acta Physica Polonica A

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2012

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vol. 122

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issue 3

520-523

EN

Magnesium alloys are promising materials for production of biodegradable implants that may be used for fixation of fractured bones. Magnesium itself is an essential element that plays important roles in many biological processes. However, some common alloying elements of magnesium alloys such as aluminium or copper may cause health problems to the organism. A major problem is the high corrosion rate of magnesium and its alloys in physiological environment that contains chloride anions. Currently, the research focuses on alloys doped by rare-earth elements and zinc. All these elements affect corrosion resistance and mechanical properties of magnesium alloys. This work was dealing with the study of Mg-Gd binary alloy and Mg-Gd-Y, Mg-Gd-Zn ternary alloys that were prepared from pure metals by melting in induction furnace. Various alloy compositions were tested. Corrosion behaviours in 9 M NaCl saline environments (exposure tests, potentiodynamic measurements) were studied on alloys in the cast state. Good corrosion resistance and uniform corrosion were observed in the case of binary Mg-Gd alloy. The influence of the addition of Y or Zn to the Mg-Gd system is discussed.

2

Powder Metallurgy Preparation of Co-Based Alloys for Biomedical Applications

76%

Marek I., Novák P., Mlynár J., Vojtěch D., Kubatík T., Málek J.

Acta Physica Polonica A

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2015

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vol. 128

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issue 4

597-601

EN

Co-based alloys represent very important group of materials used for medical applications. Currently, fabrication of these materials is preferentially done by casting or forming. Production by powder metallurgy techniques is less common. However, powder metallurgy fabrication of these alloys brings advantages such as reduced machining, possibility of alloying by high-melting elements, preparation of nanocrystalline materials with enhanced mechanical properties or producing of porous alloys with improved ability to integrate into issues. In this work, our attention was focused on fundamental preparation of an CoCrMo alloy by two methods of powder metallurgy. In the first method, pure metallic powders were mixed, pressed and sintered in vacuum furnace. The second applied technology consisted of mechanical alloying using planetary ball mill and compaction by spark plasma sintering technique. A series of samples was prepared under various conditions by these procedures. Dependence of microstructure, phase composition and mechanical properties of prepared samples on fabrication conditions (milling parameters, sintering temperature etc.) was studied. Obtained results were compared with properties of commercial cast cobalt alloy used for medical applications.

3

Preparation of Iron Nanoparticles by Selective Leaching Method

76%

Michalcová A., Vojtěch D., Kubatík T., Stehlíková K., Brabec F., Marek I.

Acta Physica Polonica A

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2015

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vol. 128

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issue 4

640-642

EN

Iron nanoparticles were prepared by selective leaching method. Initially the rapidly solidified AlFe11 alloy was prepared and consequently the aluminium matrix was dissolved from this alloy in 20% NaOH solution. This process was carried out at 0 and 80°C. At lower temperature, the iron nanoparticles covered by thin layer of Fe(OH)₃ were successfully obtained. The size of formed nanoparticles was about 8 nm and the particles exhibited massive agglomeration. It is not limitation of the process, because the application of nanoparticles is as a precursor for production of bulk nanocrystalline materials (metals, alloys and metal matrix composites). At higher temperature, the selective leaching process failed and iron was oxidized to different hydroxides. Aluminium containing waste liquid from selective leaching was used for production of powder Al₂O₃. Initial alloys and products were characterized by X-ray diffraction, scanning electron microscopy, and high resolution transmission electron microscopy.

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3 Acta Physica Polonica A

2 2015

1 2012

3 Vojtěch D.

2 Kubatík T.

2 Marek I.

1 Brabec F.

1 Kubásek J.

1 Michalcová A.

1 Mlynár J.

1 Málek J.

1 Novák P.

1 Stehlíková K.

1 Čapek J.

Properties of Biodegradable Alloys Usable for Medical Purposes

Powder Metallurgy Preparation of Co-Based Alloys for Biomedical Applications

Preparation of Iron Nanoparticles by Selective Leaching Method