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Bachelor's Thesis
Author of thesis: Bc. Milan Muránsky
Acad. year: 2025/2026
Supervisor: doc. Ing. Stanislava Fintová, Ph.D.
Reviewer: doc. Ing. Róbert Jankových, CSc.
The presented bachelor's thesis focuses on characterizing the localization of cyclic plastic deformation in pure magnesium in correlation with its hexagonal close-packed (HCP) lattice. Flawless surface preparation of the samples is a critical prerequisite for the accurate monitoring of these deformation processes and fatigue damage. Conventional mechanical grinding deforms the surface, creates a Beilby layer, and leaves sharp scratches that act as stress concentrators and completely mask real microscopic phenomena. Therefore, the experimental part compares three approaches to the final surface treatment of fatigue specimens: mechanical grinding, chemical etching, and electrolytic polishing. Surface quality and texture are evaluated quantitatively using coherent interferometry and qualitatively via light and scanning electron microscopy (SEM). The results confirmed that optimized electrolytic polishing is the most suitable method, as it successfully eliminates the deformed Beilby layer and rounds the sharp edges of the scratches without creating critical stress concentrators, even though interferometric measurements indicate the highest areal roughness values for this surface. The surface prepared in this way allows for the exact characterization of grain orientation using the EBSD method and the reliable monitoring of the natural development of slip bands during low-cycle fatigue tests.
pure magnesium , cyclic plastic deformation , surface texture , electrolytic polishing , scanning electron microscopy (SEM) , interferometry , material fatigue
Date of defence
08.06.2026
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
Študent komisii prezentuje tému svojej práce, rozoberá jej ciele. Nadväzuje svojím riešením, prezentovaním výsledkov a vyvodením záverov. Následne sú prečítané posudky vedúceho práce a oponenta. Študent odpovedá na dve otázky oponenta. Prebieha diskusia a študent odpovedá na položené otázky: Akou metodikou ste stanovali neistotu typu A a neistotu typu B? Zodpovedanie otázky: áno. Akým spôsobom riešite kumuláciu únavového poškodenia? Zodpovedanie otázky: áno. Aká veľká je analyzovaná vzorka (plocha vzorky)? Zodpovedanie otázky: áno. Akou metódou by sa merali dislokačné pásy na vzorke? Zodpovedanie otázky: áno.
Language of thesis
Slovak
Faculty
Fakulta strojního inženýrství
Department
Institute of Production Machines, Systems and Robotics
Study programme
Engineering (B-STR-P)
Specialization
Quality, Reliability and Safety (KSB)
Composition of Committee
Ing. Aleš Polzer, Ph.D. (člen) doc. Ing. Róbert Jankových, CSc. (předseda) doc. Ing. Petr Blecha, Ph.D., FEng. (místopředseda) Ing. Tomáš Marek, Ph.D. (člen) Ing. Vendula Sámelová, Ph.D. (člen) Ing. Luboš Kotek, Ph.D. (člen)
Supervisor’s reportdoc. Ing. Stanislava Fintová, Ph.D.
Grade proposed by supervisor: A
Reviewer’s reportdoc. Ing. Róbert Jankových, CSc.
Grade proposed by reviewer: B
Responsibility: Mgr. et Mgr. Hana Odstrčilová