1. Harmonizing microstructures and enhancing mechanical resilience : novel powder metallurgy approach for Zn–Mg alloysAnna Boukalová, Jiří Kubásek, David Nečas, Peter Minárik, Črtomir Donik, Drahomír Dvorský, Dalibor Vojtěch, Alena Michalcová, Matjaž Godec, Irena Paulin, 2024, original scientific article Abstract: Zinc alloys are recognised for their excellent biocompatibility and favourable corrosion rates, making them suitable for bioabsorbable implants. However, their mechanical properties necessitate improvement to fulfil the rigorous requirements of biomedical applications. This research focuses on engineering pseudo-harmonic structures within zinc alloys through a comprehensive method combining mechanical alloying, spark plasma sintering, and hot extrusion techniques. This fabrication process results in a composite material characterised by a soft core surrounded by a continuous, three-dimensional, ultrafine-grained hard shell. The experiment involved blending pure zinc with Zn–1Mg alloy powder, leading to the formation of both ductile zinc and fine-grained Zn–1Mg regions. While the Mg2Zn11 intermetallic phase was found to enhance the alloy's mechanical strength, the presence of oxide shells adversely affected the material's properties. The elimination of these shells via hot extrusion markedly improved the alloy's tensile strength, reaching an average value of tensile strength of 333 ± 7 MPa. This study provides significant insights into the material engineering of zinc-based alloys for biodegradable implant applications, demonstrating a viable approach to optimising their mechanical performance.
Keywords: zinc, magnesium, biodegradable, powder metallurgy, harmonic structure
Published in DiRROS: 23.07.2024; Views: 197; Downloads: 176
 Full text (14,29 MB)
This document has many files! More... |
2. 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, original scientific article Abstract: 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.
Keywords: zinc, mechanical alloying, biodegradable metals, composite, spark plasma sintering, extrusion, powder metallurgy
Published in DiRROS: 23.07.2024; Views: 182; Downloads: 173
Full text (21,50 MB)
This document has many files! More... |
3. |
