Topics of dissertations of ÚMMS SAV, v. v. i. beginning in academic year 2024/2025 in study programme Engineering technologies and materials in cooperation with SjF STU
Development of metal matrix composites strengthened with continuous oxide network prepared from ALD-coated powders
Supervisor: Ing. Peter Krížik, PhD.
Contact: peter.krizik@savba.sk
The aim of this doctoral thesis is the development of new types of metal matrix composites, stabilized and reinforced by the continuous network of oxides with nanometric thickness. These composites will be prepared by the consolidation of atomized metal powders (Al, Ti, Mg) coated with thin amorphous Al2O3 layers using atomic layer deposition (ALD) technology. The coated metal powders will be further processed by the powder metallurgy (PM) methods in order to prepare bulk composites with increased mechanical and physical properties. During the PhD. study, the student will be responsible for: 1. preparation of Al2O3 coatings on metal powders by ALD method, optimization of layer thickness and processing parameters 2. preparation of bulk composites from these powders by PM methods, 3. complex microstructural characterization, mechanical testing and measurement of physical properties, 4. study on the influence of Al2O3 layer thickness on the thermal stability of composites, mechanical and physical properties, 5. study of the influence of heat treatment on the mechanical and physical properties. During the study, the PhD. student is expected to handle the preparation of samples using PM technologies, will use the methods of thermal analysis (TGA, DSC, DTA) and electron microscopy (SEM, TEM), spectrometric methods (EBSD, EDS, EELS), X-ray diffraction (XRD), mechanical (tensile tests, DMA), creep tests and fractography. The PhD. thesis will be supported by the VEGA research project. Previous experience in material science, metallurgy, analysis and characterization methods, active knowledge of the English language, ability to work in a dynamic team and independence are required.
Development of a new type of biomedical bioabsorbable zinc-based metal matrix composites
Supervisor: Ing. Martin Balog, PhD.
Contact: martin.balog@savba.sk
The aim of the doctoral thesis is the development of a new generation of biomedical zinc (Zn)-based bulk metal matrix composites (MMC) fabricated by powder metallurgy (PM) approach with ultrafine-grained (UFG) structures in-situ stabilized by nanometric zincite (ZnO) dispersoids with the mechanical, corrosion and biological properties optimized for implantology, namely for an application of stents and orthopedic internal fixation devices, and which address the shortcomings of contemporary bioabsorbable materials. During the interdisciplinary work the doctoral student will be responsible for: i) fabrication and optimization of MMC by various PM technologies, ii) microstructural characterisation and mechanical testing, iii) study of expected stabilizing effect induced by in-situ ZnO dispersoids into highly strained UFG Zn grain structure, iv) study on corrosion behavior in simulated body fluids and v) in-vitro biological cell culture response of MMC extracts. The doctoral student will be required for both experimental and analytical type of research. The doctoral student will have to handle various technologies of PM, will use the methods of thermal analysis (TGA, DSC) and electron microscopy (SEM, TEM), spectrometric methods (EBSD, EDS), X-ray diffraction (XRD), mechanical (tensile tests, DMA, creep, fatigue, hardness) and corrosion tests, at collaborative bases he/she will participate on in-vitro cell culture biological response (MTT, ROS, comet, bactericidal study) assays. The doctoral thesis will be supported by a relevant research project and the student will work closely with the Biomedical centre SAS and other foreign institutions. A previous experience related to a materials research, fluent and active knowledge of the English language, the ability to work in a dynamic team and independence are required.