Leszek Chałko

Dr. Leszek Chałko

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

View All Publications
17 November 2020 in Materials
Verified
Journal Article
Open access
PDF file
Edwin Spartak GevorkyanEdwin Spartak Gevorkyan
Edwin Spartak Gevorkyan
Miroslaw RuckiMiroslaw Rucki
Miroslaw Rucki
SPSergey Panchenko
Sergey Panchenko
DSDmitry Sofronov
Dmitry Sofronov
LCLeszek Chałko
Leszek Chałko
TMTomasz Mazur
Tomasz Mazur
In this study, the effect of the addition of silicon carbide to alumina ceramics commonly used in cutting tool applications is addressed. Performance of Al2O3–SiC composite cutting inserts during the machining of hardened steels and ductile iron was compared to the results obtained for a cutting tool made out of 99 wt.% Al2O3, Al2O3–TiC, Al2O3–TiC–ZrO2, and Al2O3–TiN. In almost all tests, the composite with silicon carbide demonstrated better wear resistance, longer tool lifetime, and the ability to cut at higher speeds. The enhanced properties of cutting tools with SiC can be attributed to the morphology and dimensions of the inclusions in the matrix as well as to the strength of the interphase boundaries, small porosity, and lack of high inner stresses in the volume.

6 January 2021 in Materials
Verified
Journal Article
Open access
PDF file
DMDmitrij Morozow
Dmitrij Morozow
Marek BarlakMarek Barlak
Marek Barlak
ZWZbigniew Werner
Zbigniew Werner
Marcin PisarekMarcin Pisarek
Marcin Pisarek
PKPiotr Konarski
Piotr Konarski
Jacek CabanJacek Caban
Jacek Caban
The paper is dedicated to the life prolongation of the tools designed for deep-hole drilling. Among available methods, an ion implantation process was used to improve the durability of tungsten carbide (WC)-Co guide pads. Nitrogen fluencies of 3 × 1017 cm−2, 4 × 1017 cm−2 and 5 × 1017 cm−2 were applied, and scanning electron microscope (SEM) observations, energy dispersive spectroscopy (EDS) analyses, X-ray photoelectron spectroscopy (XPS) and Secondary Ion Mass Spectrometry (SIMS) measurements were performed for both nonimplanted and implanted tools. The durability tests of nonimplanted and the modified tools were performed in industrial conditions. The durability of implanted guide pads was above 2.5 times greater than nonimplanted ones in the best case, presumably due to the presence of a carbon-rich layer and extremely hard tungsten nitrides. The achieved effect may be attributed to the dissociation of tungsten carbide phase and to the lubrication effect. The latter was due to the presence of pure carbon layer with a thickness of a few dozen nanometers. Notably, this layer was formed at a temperature of 200 °C, much smaller than in previously reported research, which makes the findings even more valuable from economic and environmental perspectives.

13 November 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
DBDamian Bzinkowski
Damian Bzinkowski
Miroslaw RuckiMiroslaw Rucki
Miroslaw Rucki
LCLeszek Chałko
Leszek Chałko
AKArtūras Kilikevičius
Artūras Kilikevičius
Jonas MatijošiusJonas Matijošius
Jonas Matijošius
TRTomasz Ryba
Tomasz Ryba
This paper is devoted to the real-time monitoring of close transportation devices, namely, belt conveyors. It presents a novel measurement system based on the linear strain gauges placed on the tail pulley surface. These gauges enable the monitoring and continuous collection and processing of data related to the process. An initial assessment of the machine learning application to the load identification was made. Among the tested algorithms that utilized machine learning, some exhibited a classification accuracy as high as 100% when identifying the load placed on the moving belt. Similarly, identification of the preset damage was possible using machine learning algorithms, demonstrating the feasibility of the system for fault diagnosis and predictive maintenance.

10 March 2023 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Lenka CepovaLenka Cepova
Lenka Cepova
Robert ČepRobert Čep
Robert Čep
LCLeszek Chałko
Leszek Chałko
SPStepanka Dvorackova, Ph.D.
Stepanka Dvorackova, Ph.D.
MTMiroslav Trochta
Miroslav Trochta
CCChyshkala Volodymyr Volodymyr Oleksiyovych Chyshkala
Chyshkala Volodymyr Volodymyr Oleksiyovych Chyshkala
In this paper, a practical issue of the application of cubic boron nitride (CBN) cutting tools for the machining of steel 100Cr6 thin-walled bearing rings is addressed. Three geometries of the commercially available CBN cutting inserts were tested at different machining parameters. The effect of geometry was assessed in terms of surface integrity, considering 2D profile parameters, 3D topography of the surface, and residual stresses in the surface layer. The results were sometimes contradictory, since the same cutting inserts provided the largest and the lowest values of the topography parameters, dependent on different cutting conditions. In general, CBN cutting inserts with XCEL geometry ensured the smallest profile parameters Ra and Rz, and the spatial parameters of Smr1 exhibited the largest values among all tested tools, suggesting reduced wear resistance. Residual stresses analysis did not reveal any inacceptable or potentially dangerous surface layer state after machining.

30 April 2025 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Miroslaw RuckiMiroslaw Rucki
Miroslaw Rucki
Edwin Spartak GevorkyanEdwin Spartak Gevorkyan
Edwin Spartak Gevorkyan
JLJolanta Natalia Latosińska
Jolanta Natalia Latosińska
VKVasyl Kolodnitskyi
Vasyl Kolodnitskyi
LCLeszek Chałko
Leszek Chałko
TRTomasz Ryba
Tomasz Ryba
The repeatability of the material properties is required to ensure the proper performance of the engineered systems that are constructed using these materials. In this paper, an analysis of the sintered ceria-stabilized zirconia is presented. This material exhibited high mechanical properties, due to the mechanism of strengthening via phase transition. The reproducibility was assessed for the material made out of a starting powder produced by fluoride salt precipitation. To fabricate specimens, a novel electroconsolidation method was used, ensuring a high heating rate, relatively low sintering temperatures, and short holding time. Weibull analysis was performed considering the bending strength of specimens and their microhardness. The obtained values of both shape parameter m and scale parameter σ0 indicated that the ZrO2 stabilized with 5 wt.% CeO2 samples exhibited low variability of strength and hardness. The experimental evidence and statistical analysis reveal an influence of the m-phase, which has lower symmetry and therefore its addition makes ceramic weaker and softer. Furthermore, its progressive replacement by the t-phase, which has higher symmetry, makes ceramic both harder and stronger. Reducing the mol% increases the risk of the appearance of the highest addition of the monoclinic phase; increasing it is unfavorable from the point of view of the sintering process. Statistical and manufacturing evidence suggests that the choice of 5%/mol is optimal.

1 February 2023 in Advances in Science and Technology Research Journal
Verified
Journal Article
Open access
BRBoranbay Ratov
Boranbay Ratov
VMVolodymyr A. Mechnik
Volodymyr A. Mechnik
Miroslaw RuckiMiroslaw Rucki
Miroslaw Rucki
Edwin Spartak GevorkyanEdwin Spartak Gevorkyan
Edwin Spartak Gevorkyan
AKArtūras Kilikevičius
Artūras Kilikevičius
DKDmytro Korostyshevskyi
Dmytro Korostyshevskyi
The paper presents research results on the enhancement of diamond composites designed for tools application for mining industry, hard rocks cutting, able to withstand harsh conditions under heavy dynamical loads. In the present study, both CrB2 micropowder and VN nanopowder additives were used in...