CC BY
23iSHS 2019
Moscow, Russia
HIGH-TEMPERATURE Mo-(Zr,Hf)-Si-B COATINGS DEPOSITED USING
SHS-PRECURSORS
Ph. V. Kiryukhantsev-Korneev*", T. A. Sviridova", N. V. Shvindina",
and E. A. Levashov"
aNational University of Science and Technology MISiS, Moscow, 119049 Russia
*e-mail: [email protected]
DOI: 10.24411/9999-0014A-2019-10064
Nanocomposite Mo-Si-B, Mo-Zr-Si-B, and Mo-Hf-Si-B coatings were deposited by direct current (DCMS) and pulsed magnetron sputtering (PMS) of the MoSiB, MoZrSiB, and MoHfSiB composite targets, correspondingly. Targets were fabricated via hot pressing of the precursors by the self-propagating high-temperature synthesis method. The structure, element and phase composition of coatings were studied by means of scanning and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive spectroscopy, Raman, and glow discharge optical emission spectroscopy. The films were characterised in terms of their adhesion, hardness, elastic modulus, elastic recovery, fatigue strength, and fracture toughness. To evaluate oxidation resistance, the coatings were annealed in air in the temperature range of 600-1500°C during different time expositions between 10 min and 5 h.
The results obtained demonstrate that the Mo-Si-B coatings possess higher hardness of 30 GPa, improved oxidation resistance and better thermal stability compared with their Mo-Zr-Si-B and Mo-Hf-Si-B counterparts. The 14 |im thick Mo-Si-B coatings were shown to withstand successfully oxidation during short-time exposure for 10 min at temperature as high as 1500°C due to the formation of protective silica scale. The oxidation of Mo-Hf-Si-B coatings was accompanied by the diffusion of hafnium to the coating surfaces and the formation of SiO2/HfO2/SiO2 top-layer structure which were less protective against oxidation. Formation of Al2O3-SiO2 and HfO2 layers on the boundary with the substrate was also revealed in case of Mo-Hf-Si-B films. The complex layer structure SiO2/SiO2 + ZrO2/MoZrSiB/SiO2 was formed during high-temperature heating of MoZrSiB coatings. Other hand doping with hafnium and zirconium exclude the complete destruction of MoSiB coatings after annealing at 600°C due to silicide pest effect.
The work was supported by the Russian Science Foundation (Agreement no. 19-19-00117).
1. Ph.V. Kiryukhantsev-Korneev, I.V. Iatsyuk, N.V. Shvindina, E.A. Levashov, D.V. Shtansky, Comparative investigation of structure, mechanical properties, and oxidation resistance of Mo-Si-B and Mo-Al-Si-B coatings, Corros. Sci., 2017, vol. 123, pp. 319-327.
2. Ph.V. Kiryukhantsev-Korneev, A.Yu. Potanin, Structure, mechanical properties, and oxidation resistance of MoSi2, MoSiB, and MoSiB/SiBC coatings, Russ. J. Non-Ferr. Met., 2018, vol. 59, no. 6, pp. 698-708.
3. Ph.V. Kiryukhantsev-Korneev, A.V. Bondarev, D.V. Shtansky, E.A. Levashov, Structure and properties of nanocomposite Mo-Si-B-(N) coatings, Prot. Met. Phys. Chem. Surf., 2015, vol. 51, no. 5, pp. 794-802.
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