Oxidation behavior of arc evaporated TiSiN coatings investigated by in-situ synchrotron X-ray diffraction and HR-STEM

SURFACE & COATINGS TECHNOLOGY

卷:404

Article

Moritz, Yvonne¹  Saringer, Christian¹  Tkadletz, Michael²  Stark, Andreas³  Schell, Norbert³  Letofsky-Papst, Ilse^4,5  Czettl, Christoph⁶  Pohler, Markus⁶  Schalk, Nina¹ 

[1] Univ Leoben, Christian Doppler Lab Adv Coated Cutting Tools, Dept Mat Sci, Franz Josef Str 18, A-8700 Leoben, Austria

[2] Univ Leoben, Dept Mat Sci, Franz Josef Str 18, A-8700 Leoben, Austria

[3] Helmholtz Zentrum Geesthacht, Inst Mat Res, Max Plank Str 1, D-21502 Geesthacht, Germany

[4] Graz Univ Technol, NAWI Graz, Inst Electron Microscopy & Nanoanal, Steyrergasse 17, A-8010 Graz, Austria

[5] Graz Univ Technol, NAWI Graz, Ctr Electron Microscopy, Steyrergasse 17, A-8010 Graz, Austria

[6] Ceratizit Austria GmbH, Metallwerk Plansee Str 71, A-6600 Reutte, Austria

关键词: Hard coatings;    PVD;    Oxidation;    Sequential Rietveld refinement;    STEM;   

DOI  :  10.1016/j.surfcoat.2020.126632

来源: Elsevier

【 摘 要 】

Owing to its excellent mechanical and thermal properties and outstanding oxidation resistance, TiSiN is used for protective hard coatings for cutting applications. While several reports confirm the oxidation stability of TiSiN up to temperatures above 800 degrees C, literature is currently lacking a thorough investigation of the oxidation sequence of this coating system. Thus, in this study the oxidation mechanism of TiSiN was monitored via in-situ synchrotron X-ray diffraction (XRD) and complemented by a detailed analysis of the microstructure and elemental composition of oxidized coatings. A TiSiN coating was deposited by cathodic-arc evaporation in an industrial scale deposition plant. In-situ synchrotron XRD experiments of the powdered coating showed an oxidation stability up to similar to 830 degrees C, followed by the formation of both, rutile and anatase TiO2 with increasing temperature. The formation of anatase during oxidation was confirmed by Raman and XRD investigations on a solid coating. Highresolution scanning transmission electron microscopy investigations revealed the oxidation of only several hundred nm of the coating surface after oxidation at 930 degrees C for 5 min, while increasing the temperature to 1130 degrees C resulted in full oxidation of the Ti(Si)N nanocrystals, accompanied by high porosity and significant grain coarsening. Furthermore, elemental analysis showed the presence of TiO2 grains surrounded by an amorphous Si-O-N phase as well as the formation of a TiO2 top layer due to diffusion of Ti to the surface. The obtained results provide detailed and novel insight into the oxidation mechanism of TiSiN as well as on the microstructure of oxidized TiSiN coatings.

【 授权许可】

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