Karol Kobiela

Mr. Karol Kobiela

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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3 March 2021 in Coatings
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Journal Article
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ISIrina Smolina
Irina Smolina
KKKarol Kobiela
Karol Kobiela
This paper presents the method of preparation and study results of the Stellite 6 laser surface alloyed (LSA) with rhenium using na LDF diode laser (4000 W). During this process, a rhenium powder was introduced onto the surface of the Co-based alloy. The possibility of improving wear and corrosion resistance properties is interesting and worth investigating. The selected process parameters: the laser power of 900 W, powder feed rate in the range 1.92–3.83 g/min, and necessarily preheating of the substrate up to 200 °C—allowing to obtain the LSA layers on the Stellite 6 substrate. Depending on the process parameters, it is possible to modify the substrate’s surface layer in terms of rhenium concentration and geometrical characteristics of the laser tracks. It was found that undissolved particles of rhenium in laser-alloyed layers have a non-significant effect on their hardness and abrasion resistance. The laser surface-alloyed corrosion potential is better than the corrosion potential of the Stellite 6 substrate, including reducing resistance to pitting corrosion with a high ability to repassivation.

19 July 2022 in Materials
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ISIrina Smolina
Irina Smolina
KGKonrad Gruber
Konrad Gruber
APAndrzej Paweł Pawlak
Andrzej Paweł Pawlak
Grzegorz ZiółkowskiGrzegorz Ziółkowski
Grzegorz Ziółkowski
EGEmilia Grochowska
Emilia Grochowska
TKTomasz Kurzynowski
Tomasz Kurzynowski
Additive manufacturing (AM) is dynamically developing and finding applications in different industries. The quality of input material is a part of the process and of the final product quality. That is why understanding the influence of powder reuse on the properties of bulk specimens is crucial for ensuring the repeatable AM process chain. The presented study investigated the possibility of continuous reuse of AlSi7Mg0.6 powder in the laser powder bed fusion process (LPBF). To date, there is no study of AlSi7Mg0.6 powder reuse in the LPBF process to be found in the literature. This study aims to respond to this gap. The five batches of AlSi7Mg0.6 powder and five bulk LPBF samples series were characterised using different techniques. The following characteristics of powders were analysed: the powder size distribution (PSD), the morphology (scanning electron microscopy—SEM), the flowability (rotating drum analysis), and laser light absorption (spectrophotometry). Bulk samples were characterised for microstructure (SEM), chemical composition (X-ray fluorescence spectrometry—XRF), porosity (computed tomography—CT) and mechanical properties (tensile, hardness). The powder was reused in subsequent processes without adding (recycling/rejuvenation) virgin powder (collective ageing powder reuse strategy). All tested powders (powders P0–P4) and bulk samples (series S0–S3) show repeatable properties, with changes observed within error limits. Samples manufactured within the fifth reuse cycle (series S4) showed some mean value changes of measured characteristics indicating initial degradation. However, these changes also mostly fit within error limits. Therefore, the collective ageing powder reuse strategy is considered to give repeatable LPBF process results and is recommended for the AlSi7Mg0.6 alloy within at least five consecutive LPBF processes.

31 January 2023 in Materials
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MKMichał Karoluk
Michał Karoluk
KKKarol Kobiela
Karol Kobiela
MMMarcin Madeja
Marcin Madeja
RDRobert Dziedzic
Robert Dziedzic
Grzegorz ZiółkowskiGrzegorz Ziółkowski
Grzegorz Ziółkowski
TKTomasz Kurzynowski
Tomasz Kurzynowski
Despite the significant potential advantages of processing Ti-5Al-5Mo-5V-1Cr-1Fe alloy (Ti-55511) using Electron Beam Melting (PBF-EB/M), when compared to conventional manufacturing technologies, the resulting internal defects are an important characteristic of such additive technologies and can highly decrease mechanical properties. One of the most dangerous defects formed during metal additive manufacturing processes are material discontinuities such as a lack of fusion. Defects of this type, due to their “flat” nature, are difficult to characterize. For cycle-loaded specimens, where the loading force acts perpendicular to the lack-of-fusion plane, defects of this type can significantly reduce fatigue properties. This paper presents the results of research aimed at improving the fatigue properties of Ti55511 alloy by reducing the influence of the lack-of-fusion defect on fatigue damage. The static and fatigue properties of specimens in the as-built state, as well as after hot isostatic pressing (HIP) treatment, were analyzed. The effect of HIP on both the reduction of pores and the degree of sphericity when using the X-ray computed tomography (XCT) system was presented. The change in the microstructure after HIP was analyzed in terms of the change in the size of individual phases, as well as the change in the phase ratio. This paper also contains a fractographic analysis of the samples after tensile and fatigue tests.

12 March 2021 in Polymers
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MFMariusz Frankiewicz
Mariusz Frankiewicz
KKKarol Kobiela
Karol Kobiela
TKTomasz Kurzynowski
Tomasz Kurzynowski
Vacuum-pressure casting technology allows small batches of components to be manufactured from polymer materials, mainly from thermosetting plastics such as polyurethane and epoxy resins. Apart from being very simple, the process is also advantageous in that it offers a very accurately reproduced geometrical structure of the surfaces of master patterns used in mold manufacturing. This article presents the results of analyses performed for the process of replicating mechanoscopic marks with the use of three vacuum casting variants, including a hybrid vacuum-pressure casting process developed in particular for the replication purposes. The main research objective was to analyze and evaluate the influence of the parameters of the individual process variants on the quality of the obtained cast parts and on the replication accuracy without introducing additional artifacts on their surfaces. The article discusses the individual stages of the process and provides an analysis of their parameters. The replicas were evaluated for their porosity and reproduction quality with the use of CT methods and comparative photographs obtained from a light microscope.

8 March 2026 in Archives of Civil and Mechanical Engineering
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Journal Article
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KKKarol Kobiela
Karol Kobiela
ISIrina Smolina
Irina Smolina
KGKonrad Gruber
Konrad Gruber
WSWojciech Stopyra
Wojciech Stopyra
MKMichał Karoluk
Michał Karoluk
JSJolanta Szczurek
Jolanta Szczurek

2 December 2024 in Bio-Algorithms and Med-Systems
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Journal Article
Closed access
Patrycja Szymczyk-ZiółkowskaPatrycja Szymczyk-Ziółkowska
Patrycja Szymczyk-Ziółkowska
MRMałgorzata Rusińska
Małgorzata Rusińska
Grzegorz ZiółkowskiGrzegorz Ziółkowski
Grzegorz Ziółkowski
KKKarol Kobiela
Karol Kobiela
KSKinga Sekuła
Kinga Sekuła
AMAnna Miner-Kordasiewicz
Anna Miner-Kordasiewicz
Objective: Maxillofacial injuries often necessitate complex reconstructive surgeries, requiring the design and fabrication of patient-specific implants (PSIs) to restore functionality and aesthetics. A 32-year-old male patient, who sustained a mandible injury, served as a case study.Methods: This study presents advancements in maxillofacial reconstruction through the application of Electron Beam Powder Bed Fusion (PBF-EB/M), an additive manufacturing (AM) technique, in the creation of personalized jaw implants. CT scans were processed to develop a 3-D model of the patient's tissues, and Finite Element Analysis (FEA) was employed to assess mechanical behaviour. Results: The PSI, manufactured from a Ti6Al4V ELI alloy, exhibited suitable mechanical properties and biocompatibility. This work presents a workflow that clarifies the principles of designing, verifying and manufacturing PSIs for maxillofacial reconstruction. Conclusions: By integrating advanced imaging techniques, FEA simulations, and AM technologies, along with post-processing using CAM tools, the feasibility of producing personalized medical devices with modern manufacturing methods that offer enhanced design flexibility can be assessed. This includes highlighting both the potential benefits and challenges of the proposed approach.