Publikační činnost Fakulty materiálově-technologické / Publications of Faculty of Materials Science and Technology (FMT)

Permanent URI for this collectionhttp://hdl.handle.net/10084/106791

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Analysis of Selected Life Factors of Wooden Bridges
(Vysoká škola báňská - Technická univerzita Ostrava, 2022) Fojtík, Roman
The first part of the monograph contains basic information about the historical development of bridge construction not only from the environment of Central Europe. In the first block, the basic facts about the material, its properties and structure are also given. The main part of the monograph includes the original results of research on real structures and laboratory samples in order to confirm or refute the hypothesis of this work. The research results contain sets of evaluated data mainly from bridge constructions from Central Europe. Regional targeting is deliberate with regard to climate and wood-destroying factors. The monograph brings new approaches to the solution of modern wood-based bridge structures. It is mainly the design, development and testing of wood-concrete load-bearing system for bridges and insulation system for bridge construction. This work is based on historical structural and material facts about wooden bridges and footbridges and on the failures of existing structures, in order to bring a new modern solution for the development of the field of wood-based bridge construction not only for Central Europe.
PhD students´day FMST 2024
(Vysoká škola báňská – Technická univerzita Ostrava. Fakulta materiálově – technologická, 2024) Novák, Dalibor; Drobíková, Klára; Skotnicová, Kateřina
Doctoral Students’ Day 2024, organized by the Faculty of Materials Science and Technology at VŠB – Technical University of Ostrava. This year’s event, held on 14 October 2024, showcased the exceptional work, creativity, and dedication of our PhD students and their supervisors, who together drive innovation and progress across a wide range of disciplines. More than 50 contributions showcased at the event spanned diverse fields, including metallurgical technologies, materials engineering, nanotechnology, chemical and environmental engineering, chemical metallurgy, and industrial systems management. These works highlighted not only the challenges within these areas but also the innovative and practical solutions being developed by our doctoral students. Doctoral studies demand perseverance, curiosity, and a drive to make a difference. The work presented during this event exemplified these qualities and underscored the vital role our students play in shaping the future of science and engineering. Their research has a significant impact and is essential in tackling the complex challenges of today and tomorrow. We encourage all students to keep exploring, questioning, and innovating. Every step forward, no matter how small, brings us closer to new discoveries and solutions. Thank you for your dedication, and we look forward to seeing how your future work will continue contributing to the advancement of knowledge and technology.
New methods of damage and failure analyses of structural parts 2024 : 10th anniversary conference 2004-2024 : abstracts proceedings
(Vysoká škola báňská – Technická univerzita Ostrava, 2024) Holbová, Irena; Dvořák, David
The workshop ‘New Methods of Damage and Failure Analysis of Structural Parts’ provides a forum for experts on structural integrity assessment to meet and discuss new methods of assessing the reliability and safety of structures, ways of extending service life and analyzing damage in order to apply the newly acquired knowledge in designing new structures. This workshop follows on from ninth successful previous workshops held every two years from 2004 to 2022.
PhD students´day FMST 2023
(Vysoká škola báňská – Technická univerzita Ostrava. Fakulta materiálově – technologická, 2023) Novák, Dalibor; Drobíková, Klára; Skotnicová, Kateřina; Ščepková, Marcela
The authors gave oral presentations of their work online as part of a Doctoral Students’ Day held on 15 June 2023, and they reflect the challenging work done by the students and their supervisors in the fields of metallurgy, materials engineering and management. There are 82 contributions in total, covering a range of areas – metallurgical technology, thermal engineering and fuels in industry, chemical metallurgy, nanotechnology, materials science and engineering, and industrial systems management. This represents a cross-section of the diverse topics investigated by doctoral students at the faculty, and it will provide a guide for Master’s graduates in these or similar disciplines who are interested in pursuing their scientific careers further, whether they are from the faculty here in Ostrava or engineering faculties elsewhere in the Czech Republic. The quality of the contributions varies: some are of average quality, but many reach a standard comparable with research articles published in established journals focusing on disciplines of materials technology. The diversity of topics, and in some cases the excellence of the contributions, with logical structure and clearly formulated conclusions, reflect the high standard of the doctoral programme at the faculty.
PhD students´ day FMST 2022
(VŠB – Technická univerzita Ostrava, 2022) Novák, Dalibor; Drobíková, Klára; Skotnicová, Kateřina
Den doktorandů 2021
(Vysoká škola báňská – Technická univerzita Ostrava. Fakulta materiálově – technologická, 2021) Obzina, Tomáš; Wojnarová, Petra; Sova, Pavel; Tylečková, Eva
Do programu letošního „Dne doktorandů FMT“ se s prezentacemi přihlásilo celkem 49 studentů a zastoupení jednotlivých studijních programů je následující: V rámci studijního programu Metalurgická technologie je přihlášeno celkem 8 přednášejících, v oboru Chemická metalurgie 2 přednášející, v programu Tepelná technika a paliva v průmyslu 1 přednášející, v rámci studijního programu Chemické a environmentální inženýrství se přihlásil 1 přednášející, ze studijního programu Procesní inženýrství 4 přednášející. V rámci studijního programu Materiálové vědy a inženýrství se v tomto roce přihlásil 1 přednášející. Do studijního programu Řízení průmyslových systémů se pak přihlásilo 29 přednášejících. Nově se do této akce přihlásili i 3 studenti studijního programu Nanotechnologie.
Effect of thermomechanical processing via rotary swaging on properties and residual stress within tungsten heavy alloy
(Elsevier, 2020) Kunčická, Lenka; Macháčková, Adéla; Lavery, Nicholas P.; Kocich, Radim; Cullen, Jonathan C. T.; Hlaváč, Libor M.
The effects of cold and warm rotary swaging and subsequent post-process annealing on mechanical properties, residual stress, and structure development within WNiCo powder-based pseudo-alloy were predicted numerically and investigated experimentally. The swaging temperature of 900 degrees C imparted increase in the Young's and shear moduli; the post-process annealing at 900 degrees C also imparted decrease in the residual stress values, primarily due to structure recovery introduced within the matrix. Cold rotary swaging at 20 degrees C imparted ultimate tensile strength of almost 1 900 MPa, while warm rotary swaging at 900 degrees C introduced increased plasticity (almost 24 % after a single swaging pass). Post-process heat treatment promoted diffusion of W to the Ni/Co matrix, which increased strength, but remarkably decreased elongation to failure and residual stress. Numerically predicted results of mechanical behaviour corresponded to the experimental results and confirmed the favourable effects of the selected thermomechanical treatments on WNiCo performance.
The effect of processing route on properties of HfNbTaTiZr high entropy alloy
(MDPI, 2019) Málek, Jaroslav; Zýka, Jiří; Lukáč, František; Vilémová, Monika; Vlasák, Tomáš; Čížek, Jakub; Melikhova, Oksana; Macháčková, Adéla; Kim, Hyoung-Seop
High entropy alloys (HEA) have been one of the most attractive groups of materials for researchers in the last several years. Since HEAs are potential candidates for many (e.g., refractory, cryogenic, medical) applications, their properties are studied intensively. The most frequent method of HEA synthesis is arc or induction melting. Powder metallurgy is a perspective technique of alloy synthesis and therefore in this work the possibilities of synthesis of HfNbTaTiZr HEA from powders were studied. Blended elemental powders were sintered, hot isostatically pressed, and subsequently swaged using a special technique of swaging where the sample is enveloped by a titanium alloy. This method does not result in a full density alloy due to cracking during swaging. Spark plasma sintering (SPS) of mechanically alloyed powders resulted in a fully dense but brittle specimen. The most promising result was obtained by SPS treatment of gas atomized powder with low oxygen content. The microstructure of HfNbTaTiZr specimen prepared this way can be refined by high pressure torsion deformation resulting in a high hardness of 410 HV10 and very fine microstructure with grain size well below 500 nm.
Catalytic activity of advanced titanosilicate zeolites in hydrogen peroxide S-oxidation of methyl(phenyl)sulfide
(Elsevier, 2019) Martausová, Iveta; Spustová, Daniela; Cvejn, Daniel; Martaus, Alexandr; Lacný, Zdenek; Přech, Jan
Titanium-containing zeolite-based catalysts have been synthesized and investigated as catalysts in methyl (phenyl)sulfide oxidation with hydrogen peroxide. A hierarchical TS-1 prepared by the secondary templating and a layered TS-1 without and with silica and silica-titania pillars have been studied. Conventional TS-1 was a benchmarking material. The study focuses on observation of the different catalytic performance with regard to textural properties; presence and volume of mesopores and different diffusion characteristics. Thus, a deficiency and excess of the oxidizing agent were used in the catalysed reactions and the progress of reaction and selectivity to products were studied. All tested catalysts have shown after 240 min almost total conversion of methyl (phenyl)sulfide with different selectivity (substrate/catalyst mass ratio 10). It was observed that the reactants ratio hydrogen peroxide/ methyl(phenyl)sulfide influences the selectivity to sulfoxide or sulfone over a particular catalyst. In the case of hydrogen peroxide deficiency experiments (H2O2/sulfide = 0.5 mol/mol) the catalysts exhibited different distributions of products. Lamellar catalyst provided 100% selectivity to sulfoxide, the others in range of 90-65% selectivity to sulfoxide; however, the selectivity was independent on the reaction time and substrate conversion. In the case of the excess of the oxidant, except for Ti-pillared TS-1, all the catalysts showed stabile selectivity of 65% towards methyl(phenyl)sulfoxide being independent of the catalyst. The Ti-pillared TS-1 has shown, during the reaction progress, a decrease in the selectivity to sulfoxide from initial 60% to final 20% of sulfoxide at almost total conversion. The only case when higher selectivity to sulfone was achieved was gradual dosing of hydrogen peroxide.
Electric resistance welding of austenitic and galvanized steel sheets
(Sveučilište Josipa Jurja Strossmayera u Osijeku. Strojarski fakultet; Elektrotehnički fakultet; Građevinski fakultet., 2018) Hlavatý, Ivo; Hájková, Petra; Krejčí, Lucie; Čep, Robert
Nowadays the automotive industry is predominantly using heterogeneous welded joints. The welding of an austenitic and galvanized steel sheet is one of the most common applications, which are using resistive spot welding (RSW); it is a process in which contacting metal surfaces are joined by the heat obtained from resistance to an electric current The electrodes used influence the quality of a heterogeneous welded joint. This paper describes the influence of the electrodes used, their material and shapes ; and the final heterogeneous welded joint, which consists of two or three sheets. They will be compared with each other two electrode materials: CuCr1Zr original (material used for both electrodes) of new material CuCr1Zr (upper electrode replacement) and CuCo2Be (removable bottom electrode). Furthermore, the improved electrode geometry where the original planar electrode is passed to the electrode with radius surface, due to poor access to the point of welding. The aim of this research was to achieve a better quality of spot welded joints consisting of two or three sheets.
Physico-chemical characteristics of wet-milled ultrafine-granulated phosphorus slag as a supplementary cementitious material
(Wuhan University of Technology, 2018) He, Xingyang; Ye, Qing; Yang, Jin; Dai, Fei; Su, Ying; Wang, Yingbin; Strnadel, Bohumír
The phosphorus slag (PS) can be used as a supplementary cementitious material due to its potential hydrating activity. However, its usage has been limited by its adverse effects, including prolonged setting and lowered early-stage strength. In this study, we achieved ultrafine granulation of PS using wet-milling (reducing d(50) to as low as 2.02 mu m) in order to increase its activity, and examined the physico-chemical properties of the resulting materials, including particle-size distribution, slurry pH, zeta potential, and activity index, as well as how their replacement level and granularity affect the setting time and mechanical performance of PS-cement mixture systems. The results suggested that as the granularity increases, there are significant boosts in the uniformity of particle sizes, slurry pH, and activity index, and the effects on cement paste, including setting times, and early-and late-stage strengths, are significantly mitigated. When d(50)=2.02 mu m, the slurry becomes strongly alkaline (pH=12.16) compared to the initial d(50)=20.75 mu m (pH=9.49), and the activity is increased by 73%; when used at 40% replacement, the PS-cement mixture system can reach a 28 d compressive strength of 93.2 MPa, 36% higher than that of the pure cement control group.
Interaction of antitumoral drug erlotinib with biodegradable triblock copolymers: a molecular modeling study
(Springer, 2018) Hlaváč, Dominik; Klushina, Diana; Tokarský, Jonáš
Combination of molecular dynamics simulations and miscibility calculations was used to investigate erlotinib drug delivery systems based on poly-epsilon-caprolactone-polyethylene glycol-poly-epsilon-caprolactone (PCL-PEG-PCL) and poly-epsilon-caprolactone-polyglycolic acid-poly-epsilon-caprolactone (PCL-PGA-PCL) biodegradable copolymers. The molecular modeling strategy involving visual observation of models, concentration profile analysis, Flory-Huggins chi parameter, cohesive energy density, and mean square displacement calculations reproduced experimental evidence of erlotinib release from PCL-PEG-PCL matrix successfully. Increasing portion of PCL in PCL-PEG-PCL copolymer led to dissolution of erlotinib aggregates recorded in visual and concentration profile analyses. Higher portion of PCL led to higher cohesive energy density and lower mean square displacement values. Success of this strategy in reproduction of experimental data made an opportunity to utilize the same modeling design in prediction of erlotinib release from similar but not yet experimentally tested PCL-PGA-PCL matrix. In this case, agglomeration of erlotinib molecules and stronger cohesive energy density values were observed.
Abrasive water-jet technology waste and its processing possibilities
(Polskie Towarzystwo Przeróbki Kopalin, 2015) Šupolíková, Gabriela; Černý, Jakub; Gembalová, Lucie; Hlaváčová, Irena
The paper is dealing with the environmental research of waste material rising from abrasive water-jet cutting. On the occasion of disposal of the slurry from the overfull collector tank in the Laboratory of the Liquid jet of the Department of Physics at the Technical University of Ostrava the waste material was studied. Samples from different points of the catcher were collected into the beaks, dried up and consequently their elemental and structural composition has been analyzed. The results were primarily evaluated from the viewpoint of effectiveness of further abrasive recycling and usage (either as an abrasive - for this reason the residual cutting ability of the grains was discussed, or as a fine powder material for other applications - the size and shape of the grains was considered). Second viewpoint which was discussed was potential environmental hazard arising from the normal disposal of the waste material. The analysis of dried slurry samples was carried on by electron microprobe. Twenty one samples of waste mixture from various parts and depths of the tank were analyzed and compared with samples of non-used abrasive material. It was proved that abrasive material which had undergone the process of cutting was significantly impaired. It should be recycled in some cases but careful economic calculation taking into account all additional costs connected with separation of suitable abrasive fraction and its drying should be necessary. X-rays analysis provided information about chemical composition of the waste material. Most of the sludge was from abrasives, namely almandine. Higher contents of magnesium oxide, lower contents of aluminum oxide and higher contents of iron oxide, however, was probably caused by presence of other abrasive materials, such as olivine or zirconium which had been also used for cutting during the working period of the system. No potentially harmful material was detected by the X-ray analysis. It can be therefore stated that waste material from the water-jet cutting can be disposed on a common landfill without any restrictions.
Corrosion properties of anodized titanium
(Technická univerzita Košice, Hutnícka fakulta, 2017) Hlinka, Josef; Lasek, Stanislav; Faisal, Nadimul
In this paper corrosion properties and microstructure features of amorphous self-organised TiO2 nanotubes electrochemically deposited on titanium are discussed. There was titanium of second grade used as a substrate for these experiments. There was a specific solution of ammonium fluoride, ethylenglycol and deionized water used to create an oxide layer with advantageous properties. Relation between changes of roughness indexes before and after anodization was found out. The wettability (contact angle) of artificial plasma on surface was measured using sessile drop method. It was found out that titanium dioxide nanotubes formed on the surface significantly decreases contact angle and time of anodization reduces it even more. Corrosion potentials, corrosion rate or polarization resistance were determined by linear polarization methods performed by ASTM standards. Corrosion potential of anodized samples is substantially more positive (approximate to -50mV) compared with non-treated sample (approximate to - 280mV). On the other hand polarization resistance was significantly higher for non-treated sample. Also potentials of passive layer breakdowns were found. Structure of nanotubes and influence of anodization on surface profile was studied by SEM.
TiO2 and nitrogen doped TiO2 prepared by different methods; on the (micro)structure and photocatalytic activity in CO2 reduction and N2O decomposition
(American Scientific Publishers, 2018) Matějová, Lenka; Kočí, Kamila; Troppová, Ivana; Šihor, Marcel; Edelmannová, Miroslava; Lang, Jaroslav; Čapek, Libor; Matěj, Zdeněk; Kuśtrowski, Piotr; Obalová, Lucie
TiO2 as nanostructured powders were prepared by (1) sol-gel process and (2) hydrothermal method in combination with (A) the processing by pressurized hot water and methanol or (B) calcination. The subsequent synthesis step was the modification of prepared nanostructured TiO2 with nitrogen using commercial urea. Textural, structural, surface and optical properties of prepared TiO2 and N/TiO2 were characterized by nitrogen physisorption, powder X-ray diffraction, X-ray photoelectron spectroscopy and DR UV-vis spectroscopy. It was revealed that TiO2 and N/TiO2 processed by pressurized fluids showed the highest surface areas. Furthermore, all prepared materials were the mixtures of major anatase phase and minor brookite phase, which was in nanocrystalline or amorphous (as nuclei) form depending on the applied preparation method. All the N/TiO2 materials exhibited enhanced crystallinity with a larger anatase crystallite-size than undoped parent TiO2. The photocatalytic activity of the prepared TiO2 and N/TiO2 was tested in the photocatalytic reduction of CO2 and the photocatalytic decomposition of N2O. The key parameters influencing the photocatalytic activity was the ratio of anatase-to-brookite and character of brookite. The optimum ratio of anataseto- brookite for the CO2 photocatalytic reduction was determined to be about 83 wt.% of anatase and 17 wt.% of brookite (amorphous-like) (TiO2-SG-C). The presence of nitrogen decreased a bit the photocatalytic activity of tested materials. On the other hand, TiO2-SG-C was the least active in the N2O photocatalytic decomposition. In the case of N2O photocatalytic decomposition, the modification of TiO2 crystallites surface by nitrogen increased the photocatalytic activity of all investigated materials. The maximum N2O conversion (about 63 % after 18 h of illumination) in inert gas was reached over all N/TiO2.
Photoactive and non-hazardous kaolin/ZnO composites prepared by calcination of sodium zinc carbonate
(Elsevier, 2017) Janíková, Barbora; Tokarský, Jonáš; Mamulová Kutláková, Kateřina; Kormunda, Martin; Neuwirthová, Lucie
The photocatalytic activity of kaolin/ZnO composites prepared by calcination was investigated. The proposed synthesis procedure comprises the reaction of ZnCl2 with Na2CO3 in water dispersion of kaolin KICAF. Precursor sodium zinc carbonate Na2Zn3(CO3)(4).center dot 3H2O is formed and after its thermal decomposition the nanostructured ZnO is formed. Using this procedure the kaolin/ZnO composites containing similar to 6 and similar to 39 mass% of ZnO were prepared. X-ray fluorescence was used for determination of the ZnO yield. Phase composition of composites thermally treated at 100-600 degrees C was studied using X-ray diffraction method. UV-VIS diffuse reflectance spectroscopy was used to determine the band gap energy of prepared composites and their photocatalytic activity was tested by discoloration of Acid Orange 7 in aqueous solution. Composite containing 39 mass% of ZnO and calcined at 600 degrees C exhibits the highest photocatalytic activity. Leaching tests proved that the composites can be considered non-azardous.
Giant reversible inverse magnetocaloric effects in Ni50Mn35In15 Heusler alloys
(Elsevier, 2016) Quetz, Abdiel; Koshkid'ko, Yury S.; Titov, Ivan; Rodionov, Igor; Pandey, Sudip; Aryal, Anil; Ibarra-Gaytan, Pablo J.; Prudnikov, Valery; Granovskii, Alexander B.; Dubenko, Igor; Samanta, Tapas; Ćwik, Jacek; Sánchez Llamazares, J. L.; Stadler, Shane; Lähderanta, E.; Ali, Naushad
The magnetic properties and reversibility of the magnetocaloric effect of Ni50Mn35In15 have been studied in the vicinity of the phase transition using magnetization and direct adiabatic temperature change (ΔTad) measurements in magnetic fields up to 14 T. The magnetostructural phase transitions (MSTs) between a martensitic phase (MP) with low magnetization (paramagnetic or antiferromagnetic) and a nearly ferromagnetic austenitic phase were detected from thermomagnetic curves, M(T,H), at the applied magnetic fields up to 5 T. The MST temperature was found to be nearly independent of magnetic field for H < 5 T, and shifted to lower temperature with the further increase of magnetic field to 14 T. A large and nearly reversible inverse magnetocaloric effect (MCE) with ΔTad ∼ −11 К for a magnetic field change of ΔH = 14 T was observed in the vicinity of the MST. The irreversibility of ΔTad was found to be 1 K. A direct ΔTad of +7 K for ΔH = 14 T was detected at the second order ferromagnetic-paramagnetic phase transition. The obtained results have been discussed in terms of the suppression of antiferromagnetic correlations with the application of a strong magnetic field, and a reversibility of the initial magnetic state of the MP with applied magnetic field when the MST coincides with TC.
Complex processing of rubber waste through energy recovery
(Technická univerzita Košice, 2015) Smelík, Roman; Vilamová, Šárka; Chuchrová, Kateřina; Kozel, Roman; Király, Alexander; Levit, Adam; Gajda, Jakub
This article deals with the applied energy recovery solutions for complex processing of rubber waste for energy recovery. It deals specifically with the solution that could maximize possible use of all rubber waste and does not create no additional waste that disposal would be expensive and dangerous for the environment. The project is economically viable and energy self-sufficient. The outputs of the process could replace natural gas and crude oil products. The other part of the process is also the separation of metals, which can be returned to the metallurgical secondary production.
Flame resistance and mechanical properties of composites based on new advanced resin system FR4/12
(Inštitut za kovinske materiale in tehnologije, 2015) Rusnák, Vladimír; Rusnáková, Soňa; Fojtl, Ladislav; Žaludek, Milan; Čapka, Alexander
Composite materials used in the transport industry and also in other sectors must have a certain degree of flame resistance. For this purpose, commonly used flame retardants are based on halogen compounds in the liquid state or aluminum hydroxide in the solid state. Solid flame retardants have a negative effect on the processing and mechanical properties. Low viscosity and rapid wettability of fibers are very important, especially in an resin transfer molding (RTM) process. Therefore, a new advanced matrix system based on phosphorus flame retardants was developed. The flame resistance and mechanical properties of the composite materials produced from the new resin system were tested. Furthermore, the processing parameters and tests are described in the article.
Improvement of abrasive water jet machining accuracy for titanium and TiNb alloy
(Springer, 2015) Hlaváč, Libor; Gembalová, Lucie; Štěpán, Petr; Hlaváčová, Irena
The paper is dealing with abrasive water jet (AWJ) cutting of titanium and titanium–niobium alloy. It contains comparison of the experimental results with values calculated from a previously derived theoretical model describing the interaction between the AWJ and cut material using the limit values of traverse speed, limit depth of cut and limit angle. The attention is paid mainly to the angle of striations created on the walls by abrasive water jet cutting. For lower traverse rates, it was found that the angle of striations is greater than in theoretical expectations. The influence of bigger but slower peripheral abrasive particles in the AWJ outside layer is discussed as the most probable explanation of this phenomenon. Comparison of the results calculated from the theoretical model and the experiment show a very good correlation, especially when a correction, resulting from the explanation of the striation angle increase for low traverse speeds, is incorporated into the theoretical model.

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