1. Towards increased strength and retained ductility of Zn-Mg-(Ag) materials for medical devices by adopting powder metallurgy processing routesJiří Kubásek, David Nečas, Vojtěch Hybášek, Eva Jablonská, Črtomir Donik, Irena Paulin, Peter Gogola, Martin Kusý, Jaroslav Fojt, Miroslav Čavojský, Jan Duchoň, Jaroslav Čapek, 2025, izvirni znanstveni članek Povzetek: The development of bioabsorbable zinc-based alloys with tailored mechanical properties and biocompatibility holds great promise for advancing medical implant technology. In this study, Zn-Mg and Zn-Mg-Ag alloys were synthesized using mechanical alloying (MA) followed by extrusion to achieve a combination of enhanced strength, ductility, and corrosion resistance. MA for 4 hours produced ultrafine-grained powders incorporating Mg₂Zn₁₁ intermetallic phases and oxide particles, which contributed to microstructure stabilization during subsequent processing. Extrusion consolidated these powders into dense materials with a uniform grain size of ~700 nm, exhibiting ultimate tensile strengths up to 435 MPa and elongation to fracture of ~12%, representing a significant improvement over conventional processing methods. The addition of silver further enhanced the antibacterial properties, demonstrating notable efficacy against Staphylococcus epidermidis, while maintaining non-cytotoxic behavior in vitro. Corrosion rates remained low, with uniform surface degradation and the formation of protective corrosion layers. This work highlights the efficacy of combining powder metallurgy techniques to bioabsorbable zinc-based alloys with exceptional mechanical performance, corrosion behavior and in vitro cytocompatibility, providing a pathway for next-generation biodegradable medical devices.
Ključne besede: zinc, bioabsorbable materials, mechanical alloying, spark plasma sintering, microstructure
Objavljeno v DiRROS: 05.08.2025; Ogledov: 565; Prenosov: 309
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2. Enhanced performance of austenitic oxide dispersion-strengthened 316L steel: a study on ▫$Y_2O_3$▫ reinforcement and corrosion behaviourJan Pokorný, Jiří Kubásek, Črtomir Donik, David Nečas, Vojtěch Hybášek, Jaroslav Fojt, Anna Dobkowska, Irena Paulin, Jaroslav Čapek, Matjaž Godec, 2025, izvirni znanstveni članek Povzetek: This study explores the mechanical and corrosion properties of yttria-reinforced 316L stainless steel. Powder precursor materials were prepared using mechanical alloying. Varying yttria (Y2O3) contents (1, 3, and 5 wt%) were used to assess its impact on the steel’s properties. X-ray diffraction and scanning electron microscopy confirmed the successful dispersion of Y2O3 within the matrix, with the formation of chromium carbides during spark plasma sintering (SPS). The mechanical properties, including hardness and compressive yield strength, improved with increasing Y2O3 contents, with the highest strength observed in the 316L-5Y2O3 sample. However, corrosion resistance decreased with higher yttria concentrations. The 3 wt% Y2O3 sample exhibited the highest corrosion rate due to localized corrosion in areas enriched with oxide particles and chromium carbides. Electrochemical testing revealed that carbide formation and Cr-depleted regions from SPS processing contributed to the corrosion behaviour. These findings suggest that while yttria reinforcement enhances mechanical strength, optimizing the Y2O3 content and processing methods is crucial to balance both mechanical and corrosion performance in ODS 316L stainless steel.
Ključne besede: mechanical milling, SPS, 316L, austenitic stainless steel, yttria, ODS steel, corrosion, EPR-SL
Objavljeno v DiRROS: 31.01.2025; Ogledov: 855; Prenosov: 597
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3. Exploring the microstructure, mechanical properties, and corrosion resistance of innovative bioabsorbable Zn-Mg-(Si) alloys fabricated via powder metallurgy techniquesDavid Nečas, Vojtěch Hybášek, Jan Pinc, Andrea Školáková, Ilona Voňavková, Klára Hosová, Martin Zlámal, Anna Boukalová, Jan Pokorný, Drahomír Dvorský, Črtomir Donik, Dalibor Vojtěch, Jiří Kubásek, 2024, izvirni znanstveni članek Povzetek: Zinc alloys belong to the widely studied materials for applications like medical devices, however, they often
encounter an inappropriate combination of mechanical/corrosion/biological properties. In this respect, we
produced the Zn–1Mg and Zn–1Mg–1Si containing biologically friendly elements with potential strengthening
effects on zinc matrix by powder metallurgy methods including mechanical alloying, spark plasma sintering, and
extrusion further enabling the formation of materials with unique extremely fine-grained microstructures. The
systematic study of these materials showed the possibility of reaching homogeneous nano-grain microstructure
and high strength values exceeding 450 MPa in tension. Selected chemical composition and processing methods
led also to slightly decreased wear and corrosion rates and rather uniform corrosion.
Ključne besede: zinc, mechanical alloying, biodegradable metals, composite, spark plasma sintering, extrusion, powder metallurgy
Objavljeno v DiRROS: 23.07.2024; Ogledov: 1242; Prenosov: 977
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