| AVS 60th International Symposium and Exhibition | |
| Advanced Surface Engineering | Thursday Sessions |
| Session SE+NS+TF-ThA |
| Session: | Nanostructured Thin Films and Coatings |
| Presenter: | P. Zeman, University of West Bohemia, Czech Republic |
| Authors: | P. Zeman, University of West Bohemia, Czech Republic S. Proksova, University of West Bohemia, Czech Republic J. Kohout, University of West Bohemia, Czech Republic P. Mares, University of West Bohemia, Czech Republic R. Cerstvy, University of West Bohemia, Czech Republic J. Vlcek, University of West Bohemia, Czech Republic |
| Correspondent: | Click to Email |
In the present paper, the effect of Si and N addition on high temperature behavior of Zr/Hf-Si-B-C(-N) films is systematically investigated with aim to extend oxidation resistance to higher temperatures while keeping the films electrically conductive. The Zr/Hf-Si-B-C(-N) films with hardness ranging from 20 to 30 GPa were deposited on Si(100) substrates by dc pulsed magnetron co-sputtering of a single B4C-Zr/Hf-Si target (with a fixed 15% Zr/Hf fraction in the target erosion area) in argon or nitrogen-argon gas mixtures. The Si and N content in the as‑deposited films was varied in a wide range by the Si fraction in the target erosion area and by the N2 fraction in the nitrogen-argon gas mixtures, respectively. Oxidation resistance of the Zr/Hf-Si-B-C(-N) films was investigated in synthetic air using a symmetrical high-resolution Setaram TAG 2400 thermogravimetric system. Changes in the structure, elemental composition and surface morphology of the films subjected to oxidation tests were analyzed by X-ray diffraction, Rutherford backscattering spectroscopy and optical microscopy. Electrical resistivity of the as-deposited and annealed films was measured by a standard 4-point method and mechanical properties by microindentation.
The results obtained show that an addition of Si positively affects oxidation resistance of the films resulting in a reduction of their mass gains. The Zr-Si-B-C films deposited with the 20% Si fraction in the target erosion area are oxidation resistant up to 650°C and the mass gain detected at 800°C is less than 0.01 mg/cm2. An addition of N into the Zr-Si-B-C films results in a further shift of the onset of oxidation to higher temperatures. The films deposited with the 20% Si fraction in the target erosion area and with the 15% N2 fraction in the gas mixture are oxidation resistant at least up to 1000°C. As-deposited electrical conductivity and hardness of the Zr-Si-B-C-N films is maintained up to 900°C after dynamical heating in air for the 5% and 10% N2 fractions in the gas mixture. Preliminary data on the Hf-Si-B-C and Hf-Si-B-C-N films deposited at the same process parameters show even better oxidation behavior and thermal stability of electrical conductivity and hardness. These results will be discussed as well.