<div class="csl-bib-body">
<div class="csl-entry">Pölzlberger, D. E., Hahn, R., Wojcik, T., Salvadores Farran, N., Ntemou, E., Primetzhofer, D., Geiger, J., Gachot, C., & Riedl-Tragenreif, H. (2025, September 15). <i>Unravelling solid self-lubrication mechanisms of B2O3 in TiB2±z and WB2±z based thin films</i> [Conference Presentation]. 18th European Congress and Exhibition on Advanced Materials and Processes (FEMS EUROMAT 2025), Granada, Spain. http://hdl.handle.net/20.500.12708/223286</div>
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dc.identifier.uri
http://hdl.handle.net/20.500.12708/223286
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dc.description.abstract
Transition metal borides (TMBs) represent a highly promising family of materials for functional coatings due to their abundance, cost-effectiveness, and exceptional mechanical properties. These include a high melting point, hardness of up to 60 GPa, excellent chemical and thermal conductivity, and outstanding resistance to wear. TMBs have distinct self-lubricating properties due to the formation of boron oxide, which helps to reduce friction. The temperature plays a significant role in the formation of boron oxide. However, the fundamental mechanisms behind this tribo-reaction are not yet fully understood, especially concerning TMB-based thin film materials.
Understanding the oxidation behavior of physical vapor deposited TiB2±z and WB2±z thin films is essential for comprehending their friction and wear properties in high-temperature tribo contacts. Tribological tests reveal that sputter deposited super-stoichiometric TiB3.5 exhibits a significantly lower friction coefficient (~0.25), roughly half compared to that of sub-stoichiometric TiB1.67, tested at 500°C. This reduction is attributed to the higher oxidation rate of super-stoichiometric TiB3.5 and the presence of B-rich tissue phases at the column boundaries. Similarly, α-WB2±z coatings also exhibit self-lubrication properties. However, they tend to stabilize in the sub-stoichiometric form, resulting in reduced amounts of boron available for oxidation.
Additionally, we conduct an in-situ investigation of the oxidation process in sub- and super-stoichiometric TiB2±z and WB2±z thin films using elastic backscattering spectrometry (EBS). This technique provides detailed depth profiles of the chemical composition over a temperature range from room temperature to 800°C. The oxidation data are further correlated with tribological, XPS, XRD, and TEM analyses, offering new insights into the lubrication mechanisms of boron oxide in TMB thin films across a wide temperature range.
en
dc.description.sponsorship
FWF - Österr. Wissenschaftsfonds
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dc.language.iso
en
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dc.subject
self-lubrication
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dc.subject
transition metal borides
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dc.subject
friction
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dc.subject
boron oxide
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dc.title
Unravelling solid self-lubrication mechanisms of B2O3 in TiB2±z and WB2±z based thin films
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dc.type
Presentation
en
dc.type
Vortrag
de
dc.contributor.affiliation
Uppsala University, Sweden
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dc.contributor.affiliation
Uppsala University, Sweden
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dc.contributor.affiliation
TU Wien, Austria
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dc.relation.grantno
PAT1205324
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dc.type.category
Conference Presentation
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tuw.project.title
Unravelling the Solid Self-Lubrication Mechanisms of Boron Oxide on Transition Metal Boride Thin Films
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tuw.researchinfrastructure
Analytical Instrumentation Center
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tuw.researchinfrastructure
Röntgenzentrum
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tuw.researchinfrastructure
Universitäre Service-Einrichtung für Transmissionselektronenmikroskopie
