Aikaterini Argyrou

Dr. Aikaterini Argyrou


Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

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

Representative Publications

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8 August 2025 in Metals
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Journal Article
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AAAikaterini Argyrou
Aikaterini Argyrou
LGLeonidas Gargalis
Leonidas Gargalis
LKLeonidas Karavias
Leonidas Karavias
EKEvangelia K. Karaxi
Evangelia K. Karaxi
Elias KoumoulosElias Koumoulos
Elias Koumoulos
This study investigates the combined effects of build planes and heat treatments on the micro- and nanoscale mechanical properties of additively manufactured AlSi10Mg alloy. The hardness and elastic modulus were examined across two principal planes, XY and XZ, under three conditions: as-built (AB), after solution annealing followed by water quenching (SA), and artificially aged after solution annealing (SA&AA). The results reveal that hardness is significantly affected by heat treatment, decreasing after SA and partially recovering upon subsequent artificial aging (SA&AA), while remaining largely unaffected by build planes, with average values differing by less than 2%. In contrast, the elastic modulus demonstrates a clear anisotropy, correlated with the microstructural changes from both additive manufacturing and thermal post-processing. The XY plane initially shows a modulus up to 29% higher than the XZ plane. However, after aging, the values of both planes converge to similar levels. While average values suggest general trends, localized measurements reveal notable spatial heterogeneity in both the hardness and elastic modulus—particularly after thermal treatments—arising from microstructural evolutions. These findings highlight the complex interplay between orientation and thermal history, underscoring that the mechanical performance of AlSi10Mg is governed by the synergistic effects that influence anisotropy and local mechanical behavior.

12 March 2026 in Applied Sciences
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Journal Article
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AAAikaterini Argyrou
Aikaterini Argyrou
LGLeonidas Gargalis
Leonidas Gargalis
LKLeonidas Karavias
Leonidas Karavias
EKEvangelia K. Karaxi
Evangelia K. Karaxi
Elias KoumoulosElias Koumoulos
Elias Koumoulos
Laser Powder Bed Fusion (LPBF)-processed AlSi10Mg produces highly heterogeneous microstructures, where fine α-Al cells, Si-rich networks, and melt-pool boundaries govern local mechanical behavior. Nanoindentation has emerged as a key tool for probing these variations, yet systematic understanding of the links between processing parameters, microstructure, and nano-mechanical response remains limited. This critical review examines how laser processing parameters influence local mechanical response through their impact on microstructural features. Key challenges in interpreting nanoindentation are highlighted, alongside inconsistencies in experimental protocols and reporting practices that hinder cross-study comparisons. Beyond summarizing existing findings, underexplored aspects of nanoindentation in LPBF AlSi10Mg are identified, including spatially correlated microstructure-mechanical mapping, depth-resolved measurements, and integration with advanced characterization and data-driven approaches. By synthesizing current knowledge and clarifying methodological constraints, this review positions nanoindentation not merely as a descriptive tool, but as a mechanistically informed approach for linking processing conditions, microstructural heterogeneity, and local mechanical response. These insights aim to support more rigorous interpretation of small-scale mechanical data and to guide future studies toward predictive understanding and rational process optimization in additively manufactured aluminum alloys.

26 November 2025 in Applied Sciences
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Journal Article
Open access
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LGLeonidas Gargalis
Leonidas Gargalis
LKLeonidas Karavias
Leonidas Karavias
AAAikaterini Argyrou
Aikaterini Argyrou
EKEvangelia K. Karaxi
Evangelia K. Karaxi
Elias KoumoulosElias Koumoulos
Elias Koumoulos
This paper studies the influence of laser power and scanning speed through single laser scan tracks on AlNiCo5 and SS 304 substrates. Track morphologies and melt pool geometries were assessed to determine the prevailing melting modes. Cracking was observed only on AlNiCo5 substrates, while SS 304 substrates exhibited crack-free tracks, highlighting the advantages of its ductile FCC structure. Optimal laser powder bed fusion process parameters for AlNiCo5 fabrication were identified as 190 W and 600–900 mm/s for stable conduction melting, while for higher laser power processing, 270 W and 600–800 mm/s provided stable transition melting. Microhardness measurements, nanoindentation, and energy-dispersive X-ray spectroscopy were employed to analyze mechanical properties and compositional variation within the melt pools. Increased laser power led to noticeable dilution of the SS 304 substrate into the AlNiCo5 tracks, reducing the melt pool’s overall microhardness due to altered chemical composition. Nanoindentation analysis further confirmed localized mechanical heterogeneity within the melt pool, with Co- and Al-rich zones showing elevated nanohardness, elastic modulus, and resistance to plastic deformation (H/Er, H3/Er2), while substrate-diluted areas (Cr-enriched) exhibited softening linked to BCC-to-FCC phase transformation.

Verified
Journal Article
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SSStratos Saliakas
Stratos Saliakas
VGVasiliki Glynou
Vasiliki Glynou
DPDanai E. Prokopiou
Danai E. Prokopiou
AAAikaterini Argyrou
Aikaterini Argyrou
VTVaia Tsiokou
Vaia Tsiokou
Elias KoumoulosElias Koumoulos
Elias Koumoulos
A tiered approach is presented for evaluating occupational risks during liquid deposition modelling (LDM) using ceramic materials for manufacturing complex geometries in construction. The ceramic paste is comprised of kaolin/zeolite powders mixed with deionised water at a specific ratio. The tiered occupational risk analysis covered (i) the material evaluation and information gathering, (ii) on-site exposure measurements to ultrafine and micro-size particles, and (iii) morphological and toxicological analyses of raw and collected air samples. Results indicated an increase in PM4 (particle diameter < 4 μm) concentrations during powder preparation, reaching up to 1 mg/m3 during powder preparation, although below the corresponding substance-specific and general dust occupational exposure limit and with no increased exposure to ultrafine particles, as supported by morphological analysis. In toxicity assessment, reactive oxygen species production (ROS) reached approximately 300% for 50 μg/mL raw kaolin powder, while inducing high upregulation of TNF-α and IL-6 mRNA expression genes, indicating activation of pro-inflammatory pathways. Airborne samples resulted in cell viability reduction by ~50% at 40 μg/mL, showing significance (p-value < 0.001). Translating these findings to human risk remains difficult, yet the findings highlight an urgent requirement for continuous exposure surveillance, tailored toxicity evaluations, and robust protective strategies throughout ceramic manufacturing.

21 October 2026 in Coatings
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Journal Article
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AAAikaterini Argyrou
Aikaterini Argyrou
MAMaite Redín Azcona
Maite Redín Azcona
DWDiandian Wu
Diandian Wu
XLXiaoying Li
Xiaoying Li
HDHanshan Dong
Hanshan Dong
Elias KoumoulosElias Koumoulos
Elias Koumoulos
TiAlN-based coatings are widely used in demanding machining applications; however, further improvement of their mechanical and tribological performance is required under increasingly severe operating conditions. In this study, the effect of progressive refractory metal alloying on the performance of TiAlN-based coatings was investigated by comparing TiAlN, TiAlMoN, and TiAlMoWN coatings deposited by reactive magnetron sputtering. The incorporation of Mo and Mo/W induced compositional and microstructural modifications, resulting in fine surface and cross-sectional structure features. Alloying progressively improved the mechanical response, with increased hardness and higher H/Er and H3/Er2 ratios, suggesting improved elastic strain tolerance and resistance to plastic deformation. The tribological performance was strongly influenced by alloying, with Mo addition reducing the wear rate by approximately 50% compared with the TiAlN reference coating, while subsequent W incorporation maintained the improved wear resistance and further increased hardness and deformation-resistance indicators. These results demonstrate that the performance of multicomponent TiAlN-based coatings must be assessed through their mechanical response and sliding durability rather than hardness alone. The findings provide insight into the design of refractory metal-alloyed nitride coatings for high-performance machining applications.