Fracture properties of α– and k–Al2O3 hard coatings deposited by chemical vapor deposition

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung


Although α– and κ–Al 2 O 3 hard coatings deposited by chemical vapor deposition are well established in the metal-cutting industry for their ability to increase the performance and lifetime of cutting tools, the literature on their fracture properties is scarce. Thus, within this study, the mi-crostructure and mechanical properties of α– and κ–Al 2 O 3 coatings were investigated and compared to each other. X-ray diffraction and scanning electron microscopy combined with electron backscatter diffraction showed that both coatings exhibited a fiber texture, where the α–Al 2 O 3 coating displayed a (0001) texture and the κ–Al 2 O 3 coating a (001) texture with a certain (013) contribution. Higher hardness and Young’s modulus values of 31.0 ± 0.9 GPa and 474.6 ± 12.5 GPa, respectively, were ob-tained for the α–Al 2 O 3 coating, compared to 24.2 ± 0.8 GPa and 356.8 ± 7.9 GPa for κ–Al 2 O 3 . While the α–Al 2 O 3 coating exhibited a higher fracture stress of 8.1 ± 0.3 GPa (compared to 6.4 ± 0.6 GPa for κ–Al 2 O 3 ), the κ–Al 2 O 3 coating showed a higher fracture toughness of 4.4 ± 0.3 MPa*m 1/2 (compared to 3.2 ± 0.3 MPa*m 1/2 for alpha).

PublikationsstatusVeröffentlicht - 4 Nov. 2021

Bibliographische Notiz

Funding Information:
The authors gratefully acknowledge the financial support under the scope of the COMET program within the K2 Center ?Integrated Computational Material, Process and Product Engineering (IC-MPPE)? (Project No 859480). This program is supported by the Austrian Federal Ministries for Climate Action, Environment, Energy, Mobility, Innovation and Technology (BMK) and for Digital and Economic Affairs (BMDW), represented by the Austrian research funding association (FFG), and the federal states of Styria, Upper Austria and Tyrol.

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© 2021 by the authors. Licensee MDPI, Basel, Switzerland.

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