Ing. Karel Němec, Ph.D.
E-mail:   nemec.k@fme.vutbr.cz  Dept.:   Institute of Materials Science and Engineering Dept. of Mechanics and Design of Materials Position:   Assistant Professor Room:   A3/309

Supervised courses:

• Industrial Project (N-MTI) (0PPW)
• Testing of Materials and Products (DZM-K)
• Testing of Materials and Products (DZM)

Publications:

• SLÁMEČKA, K.; ČELKO, L.; SKALKA, P.; POKLUDA, J.; NĚMEC, K.; JULIŠ, M.; KLAKURKOVÁ, L.; ŠVEJCAR, J.:
  Bending fatigue failure of atmospheric-plasma-sprayed CoNiCrAlY + YSZ thermal barrier coatings
  journal article in Web of Science
• SLÁMEČKA, K.; NĚMEC, K.; ČELKO, L.; HORNÍKOVÁ, J.; POKLUDA, J.; ŠVEJCAR, J.:
  Bending Fatigue Behaviour of Diffusion and Thermal Barrier Coating Systems,
  Key Engineering Materials, pp.716-719, ISBN 9783037859346, (2014), Trans Tech Publications Ltd
  conference paper
  akce: Materials Structure & Micromechanics of Fracture (MSMF-7), Brno, 01.07.2013-03.07.2013
• PETRENEC, M.; VRASPÍROVÁ, E.; NĚMEC, K.; HECZKO, M.:
  Effect of Cyclic Heat Treatment on Cast Structure of TiAl Alloy,
  Key Engineering Materials (print), Vol.586, (2013), No.9, pp.222-225, ISSN 1013-9826, Trans Tech Publications
  journal article - other
• ČELKO, L.; KLAKURKOVÁ, L.; SLÁMEČKA, K.; HUTAŘOVÁ, S.; JULIŠ, M.; NĚMEC, K.; PODRÁBSKÝ, T.; ŠVEJCAR, J.:
  STRUCTURAL STABILITY OF THERMAL BARRIER COATINGS PRODUCED BY THERMAL SPRAYING,
  METAL 2012 Conference proceedings, pp.998-1004, ISBN 978-80-87294-29-1, (2012), TANGER Ltd.
  conference paper
  akce: METAL 2012: 21st International Conference on Metallurgy and Materials, Brno, 23.05.2012-25.05.2012

List of publications at Portal BUT

Abstracts of most important papers:

• ČELKO, L.; KLAKURKOVÁ, L.; SLÁMEČKA, K.; HUTAŘOVÁ, S.; JULIŠ, M.; NĚMEC, K.; PODRÁBSKÝ, T.; ŠVEJCAR, J.:
  STRUCTURAL STABILITY OF THERMAL BARRIER COATINGS PRODUCED BY THERMAL SPRAYING,
  METAL 2012 Conference proceedings, pp.998-1004, ISBN 978-80-87294-29-1, (2012), TANGER Ltd.
  conference paper
  akce: METAL 2012: 21st International Conference on Metallurgy and Materials, Brno, 23.05.2012-25.05.2012
  One type of functionally graded coating system is thermal barrier coating (TBC), where the combination of ceramic and metallic coating is used both to reduce the temperature and to increase oxidation and corrosion resistance of the substrate. TBCs usually consist of the top ceramic coating based on YSZ (ZrO2+Y2O3) and the metallic bond coating of M-CrAlY type, where M means Ni, Co or their appropriate combination. Electron beam physical vapour deposition (EB-PVD) or vacuum (VPS), low pressure (LPPS) or atmospheric (APS) plasma spraying techniques are most frequently used as a deposition method. Despite some requirements on the product shape simplicity, the air plasma spraying offers high productivity, sufficient quality and much lower production costs in comparison with the EB-PVD technology. The contribution deals with high temperature structural stability of TBCs of YSZ + NiCrAlY and YSZ + CoNiCrAlY types that were produced by air plasma spraying on the INCONEL 713LC polycrystalline nickel based superalloy substrate. Immediately after deposition, the specimens were exposed to temperature of 1000 C for 5-500 hours in the common ambient atmosphere. The changes in both microstructure and chemical composition were studied by means of scanning electron microscopy, energy dispersive microanalysis and image analysis methods.
• KLAKURKOVÁ, L.; ČELKO, L.; DOLEŽAL, P.; MAN, O.; NĚMEC, K.:
  Elements interaction analyses during preparation of Al-Al3Ni eutectic composites,
  Chemické listy (S), Vol.102, (2008), No.S, pp.884-885, ISSN 1803-2389, Brno University of Technology, Faculty of Chemistry
  journal article - other
  akce: 4th Meeting on Chemistry & Life, Brno, 09.09.2008-11.09.2008
  Understanding of equilibrium and non-equilibrium thermodynamic phase transformations is one of the basic condition for design of intermetallic particle strenghted composites. The Al-Ni binary systems is already used for high teamperature applications (Nickel based superalloys and high temperature protective coatings) where the Ni3Al and NiAl intermetalics widely appear. But this system contains another intermetallic compounds Al3Ni, Al3Ni2, Al3Ni5 which are neglected in high temperature studies. These intermetallic compounds can be employed as sternghtening phases in Al-based composites. The advantages of these materials are low density and relatively good chemical resistance. They can reach attractive properties in combination with less known Al-Ni intermatallic phases strenghtening. This paper is focused on the developement of Al-based composites prepared by HVOF nickel powder deposition on Al substrate. Use of this method alone is menting point of pure Al. The temperatures for difusion and formation of this intermetallics phases are in the range from 600 to the 630oC. For this study the light microscopy, scanning electron microscopy, energy dispersive microanalyses and image analyses were used.
• NĚMEC, K.; PODRÁBSKÝ, T.; VĚCHET, S.:
  HODNOCENÍ STUPNĚ DEGRADACE STRUKTURY NIKLOVÝCH SUPERSLITIN VLIVEM ZATĚŽOVÁNÍ ZA VYSOKÝCH TEPLOT,
  Materiálové inžinierstvo, Vol.14, (2007), No.3/2007, pp.159-162, ISSN 1335-0803, EDIS Zilina
  journal article - other
  The aim of this work is the study of structural changes of the material Inconel 7I3 LC by image analysis. It is focused on short-time creep tests at temperatures 850 C and 950 C.
• PODRÁBSKÝ, T., HAKL, J., BELAN, J., VLASÁK, T., MAN, O.:
  DEGRADACE STRUKTURY LOPATKY PLYNOVÉ TURBINY ZE SLITINY ŽS6K VLIVEM PROVOZU,
  Archiwum odlewnictwa, Vol.4, (2004), No.11, pp.117-122, ISSN 1642-5308
  journal article - other
  Blades made of cast Ni base superalloy ZHS6K after service in gas turbine were analyzed with the aim to characterize changes in structure. Structure degradation was analysed by light and electron microscopy. Harmful phase s was detected in matrix by EDS and ESBD analysis.
• NĚMEC, K.; USTOHAL, V.; VĚCHET, S.:
  The effect of annealing and surface treatment on fatigue characteristics of welded joints on the tubes of titanium alloy Ti-3Al-2,5V,
  European Conference Junior Euromat 2000, pp.210-211, (2000), Deutsche Gesellschaft für Materialkunde e.V.
  conference paper
  akce: Junior Euromat 2000, Lausanne, 28.08.2000-01.09.2000
  The poster deals with the effect of annealing (480C/ 2h in vacuum) on fatigue characteristics of welded joints on a tube of titanium alloy Ti-3Al-2,5V vith ERTi-6Al-4V filler metal at gas tungsten-arc manual welding with argon as a shielding gas. Here the effect of surface treatment (peening) on the same welded joints is described. The fatigue tests were executed on HF tuned pulsator Amsler 10 HFP 1478. From comparison measured Wöhlers curves the distinct influence of surface treatment (peening) on fatigue characteristics of tested joints was detected. On the contrary, no distinct influence of stress-relief annealing (480C/ 2h in vacuum) was detected. Result: The fatigue characteristics of examined welded joint can be very distinctly influenced by surface treatment, in a given case by peening. The effect of stress-relief annealing is neglectable.