<div class="csl-bib-body">
<div class="csl-entry">Fuger, C., Hahn, R., Hirle, A. V., Kutrowatz, P., Weiss, M., Limbeck, A., Hunold, O., Polcik, P., & Riedl-Tragenreif, H. (2022). Revisiting the origins of super-hardness in TiB2+z thin films – Impact of growth conditions and anisotropy. <i>Surface and Coatings Technology</i>, <i>446</i>, Article 128806. https://doi.org/10.1016/j.surfcoat.2022.128806</div>
</div>
-
dc.identifier.issn
0257-8972
-
dc.identifier.uri
http://hdl.handle.net/20.500.12708/142540
-
dc.description.abstract
Hexagonal transition metal diborides embody promising material systems for the purpose of protective thin films. Here, we focus on DC magnetron sputtered TiB2+z coating materials, comprehensively revisiting the impact of the stoichiometry on the structure-mechanical properties, from nearly stoichiometric TiB2.07 (B: 67 at. %) up to super-stoichiometric TiB4.42 (B: 82 at. %). The structural analysis confirmed the apparent correlation between the deposition pressure and the preferred {0001} orientation, which is essential to gain super-hardness (>40 GPa). In contrast, the hardness decreases for >10 GPa for 101¯1 and 1000 oriented thin films, underlining the pronounced anisotropy of TiB2+z. The broad stoichiometry variation revealed no predominant hardness effect based on a B-rich tissue phase. The excess B contributes to a decreasing column size correlating with a decreasing hardness of ≈ 7 GPa (B/Ti ratios >2.5) due to column boundary sliding events. Micro-cantilever bending experiments proved a declining fracture toughness from 3.02 ± 0.13 MPa√m for TiB2.43 to 2.51 ± 0.14 MPa√m for TiB4.42 to be column size dependent.
en
dc.description.sponsorship
CDG Christian Doppler Forschungsgesellschaft
-
dc.language.iso
en
-
dc.publisher
Elsevier
-
dc.relation.ispartof
Surface and Coatings Technology
-
dc.rights.uri
http://creativecommons.org/licenses/by/4.0/
-
dc.subject
Anisotropy
en
dc.subject
Fracture toughness
en
dc.subject
Stoichiometry
en
dc.subject
Super-hardness
en
dc.subject
TiB₂
en
dc.title
Revisiting the origins of super-hardness in TiB2+z thin films – Impact of growth conditions and anisotropy