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Povzetek: Magnesium and its alloys have emerged as promising materials for biomedical applications due to their light weight, mechanical compatibility with bone, biodegradability, and excellent biocompatibility. However, their rapid degradation in physiological environments remains a critical challenge. To address this, a range of surface-modification techniques have been explored to tailor the surface properties while preserving the bulk characteristics of magnesium. This paper provides an overview of surface-engineering methods aimed at enhancing the corrosion resistance, mechanical performance and bioactivity of magnesium. Three key surface-modification approaches are presented: plasma treatment, laser texturing and sandblasting. Plasma treatment resulted in the formation of a stable, protective oxide layer with significantly improved corrosion resistance and hydrophilicity. Laser texturing generated hierarchical microstructures yielding superhydrophobic surfaces with an enhanced hardness, though slightly reduced corrosion resistance. Sandblasting led to an increased surface roughness and mechanical stiffness, but also introduced microstructural defects that are detrimental to the corrosion stability. Overall, the study demonstrates how tailored surface modifications can effectively balance the mechanical integrity and degradation behavior of magnesium, paving the way for its optimized use in biomedical applications.
Ključne besede: magnesium, surface modification, biomaterial
Objavljeno v DiRROS: 18.06.2025; Ogledov: 582; Prenosov: 268
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Ključne besede: nanocomposites, gamma radiation, silver nanowires, graphene oxyde
Objavljeno v DiRROS: 12.05.2025; Ogledov: 736; Prenosov: 347
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Povzetek: This work aims to evaluate the corrosion and biocompatibility properties of oxide films generated on Ti6Al4V alloys using both traditional and novel methods. Oxide films were generated by anodization and plasma treatment to achieve a blue surface finish. The oxide films were then characterized and compared to a native film formed on the Ti6Al4V. Electrochemical tests, incorporating potentiodynamic tests and electrochemical impedance spectroscopy, were employed to define the electrochemical resistance of oxides in an environment simulating biological exposure. In vitro tests were conducted to study ion release and biocompatible properties over a 6-week period of exposure to a 0.9 wt% NaCl solution, at body temperature. Various spectroscopic techniques, including ToF-SIMS, XRD, and Raman analysis, were used to study the structure and chemistry of the oxide films. The sub-surface layer was analysed by microstructural investigation. The type of oxidation was found to have a key influence on the oxide composition, especially with respect to the depth distribution of the individual alloy elements through the oxide film. The oxidation process determines which of the alloying elements are released into the environment, as a result of the corrosion reactions.
Ključne besede: oxide film, biocompatibility, surface characterization, ion release, simulated body fluid
Objavljeno v DiRROS: 16.10.2024; Ogledov: 1191; Prenosov: 780
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Objavljeno v DiRROS: 04.04.2024; Ogledov: 1063; Prenosov: 444
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Povzetek: In the present work, the functionalisation of austenitic stainless steel, AISI 316L surfaces via nanosecond Nd:YAG laser texturing in order to modify the surface morphology with crosshatch and dimple patterns is presented. A tribological analysis under lubrication with sunflower and jojoba oil with and without the addition of a solid lubricant, MoS2 nanotubes, was performed. In conjunction with friction/wear response laser-textured surface wettability, oil spreadability and oil retention capacity were also analysed. It was shown that the crosshatch pattern generally exhibited lower friction than the dimple pattern, with the addition of MoS2 nanotubes not having any significant effect on the coefficient of friction under the investigated contact conditions. This was found in addition to the better oil spreadability and oil retention capacity results of the crosshatch-textured surface. Furthermore, texturing reduced the wear of the stainless-steel surfaces but led to an approximately one order of magnitude larger wear rate of the steel counter-body, primarily due to the presence of hard bulges around the textured patterns. Overall, the crosshatch pattern showed better oil retention capacity and lower friction in combination with different vegetable oils, thus making it a promising choice for improving tribological performance in various environmentally friendly applications.
Ključne besede: tribology, stainless steel, vegetable oil lubrication, MoS2 nanotubes
Objavljeno v DiRROS: 02.02.2024; Ogledov: 6265; Prenosov: 666
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