Jan Zouhar

Dr. Jan Zouhar

Brno University of Technology, Brno, Jihomoravský Kraj, Czech Republic
orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 April 2023 in Materials
Verified
Journal Article
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JSJosef Sedlak
Josef Sedlak
ZJZdenek Joska
Zdenek Joska
JJJiri Jansky
Jiri Jansky
JZJan Zouhar
Jan Zouhar
SKStepan Kolomy
Stepan Kolomy
JJJan Jirousek
Jan Jirousek
The Fused Filament Fabrication (FFF) method is an additive technology that is used for the creation of prototypes within Rapid Prototyping (RP) as well as for the creation of final components in piece or small-series production. The possibility of using FFF technology in the creation of final products requires knowledge of the properties of the material and, at the same time, how these properties change due to degradation effects. In this study, the mechanical properties of the selected materials (PLA, PETG, ABS, and ASA) were tested in their non-degenerate state and after exposure of the samples to the selected degradation factors. For the analysis, which was carried out by the tensile test and the Shore D hardness test, samples of normalized shape were prepared. The effects of UV radiation, high temperature environments, high humidity environments, temperature cycles, and exposure to weather conditions were monitored. The parameters obtained from the tests (tensile strength and Shore D hardness) were statistically evaluated, and the influence of degradation factors on the properties of individual materials was assessed. The results showed that even between individual manufacturers of the same filament there are differences, both in the mechanical properties and in the behavior of the material after exposure to degradation effects.

19 May 2024 in Alexandria Engineering Journal
Verified
Journal Article
Open access
SKStepan Kolomy
Stepan Kolomy
MMMartin Maly
Martin Maly
JSJosef Sedlak
Josef Sedlak
JZJan Zouhar
Jan Zouhar
MSMartin Slany
Martin Slany
KKKarel Kouril
Karel Kouril

20 January 2023 in Materials
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Journal Article
Open access
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SKStepan Kolomy
Stepan Kolomy
JSJosef Sedlak
Josef Sedlak
JZJan Zouhar
Jan Zouhar
MSMartin Slaný
Martin Slaný
MBMarek Benč
Marek Benč
JMJozef Majerik
Jozef Majerik
This paper deals with the study of high-strength M300 maraging steel produced using the selective laser melting method. Heat treatment consists of solution annealing and subsequent aging; the influence of the selected aging temperatures on the final mechanical properties—microhardness and compressive yield strength—and the structure of the maraging steel are described in detail. The microstructure of the samples is examined using optical and electron microscopy. The compressive test results show that the compressive yield strength increased after heat treatment up to a treatment temperature of 480 °C and then gradually decreased. The sample aged at 480 °C also exhibited the highest observed microhardness of 562 HV. The structure of this sample changed from the original melt pools to a relatively fine-grained structure with a high fraction of high-angle grain boundaries (72%).

1 September 2008
Verified
Conference Paper
Closed access
Zdenek HadasZdenek Hadas
Zdenek Hadas
JZJan Zouhar
Jan Zouhar
VSVladislav Singule
Vladislav Singule
COCestmir Ondrusek
Cestmir Ondrusek
This paper deals with an alternative design of an electromagnetic energy harvesting generator for supplying wireless sensors with energy. The developed device is complex mechatronics system which generates an electrical power from an ambient mechanical vibration by use of a suitable construction of electromagnetic generator. The developed design of generator has immobile parts base on rapid prototyping parts from ABS plastic material. It is suitable for product of device and it provides lightweight device with sufficient durability. As this device is excited by ambient mechanical vibration, it harvests electrical energy due to Faradaypsilas law.

7 June 2023 in Scientific Reports
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Journal Article
Open access
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JSJosef Sedlak
Josef Sedlak
JZJan Zouhar
Jan Zouhar
SKStepan Kolomy
Stepan Kolomy
MSMartin Slany
Martin Slany
ENEmil Necesanek
Emil Necesanek
Drilling into the solid material is one of the basic technological operations, which creates a cylindrical hole in an appropriate time with required quality. Drilling operation demands a favourable removal of chips from the cutting area because a creation of an undesirable shape of chips can impart a lower quality of the drilled hole corresponding with the generation of excess heat due to the intense contact of the chip with drill. The solution for a proper machining is a suitable modification of the drill geometry i.e., point and clearance angles as presented in current study. The tested drills are made of M35 high-speed steel characterized by a very thin core at the point of the drill. An interesting feature of the drills is the use of cutting speed higher than 30 m min−1, with the feed of 0.2 mm per revolution. The surface roughness (Ra and Rz lower than 1 µm and 6 µm respectively), cylindricity (0.045 mm), roundness (0.025 mm), perpendicularity of the hole axis (0.025 mm), diameters and position of the individual holes were achieved for a drill with point angle 138.32°and clearance angle 6.92 respectively. The increase of the drill point angle by 6° resulted in the decrease in the feed force of more than 150 N. In addition, an increase of the clearance angle by 1° resulted with a decrease in the feed force of 70 N. The results of the experiment showed that with the correct geometry of the tool the effective machining without using internal cooling can be realised.

22 May 2025 in Materials & Design
Verified
Journal Article
Open access
SKStepan Kolomy
Stepan Kolomy
MMMartin Maly
Martin Maly
MDMarek Doubrava
Marek Doubrava
JSJosef Sedlak
Josef Sedlak
JZJan Zouhar
Jan Zouhar
JCJan Cupera
Jan Cupera