Formation of Solid Lubricants during High Temperature Tribology of Silver-Doped Molybdenum Nitride Coatings Deposited by dcMS and HIPIMS

Coatings

Tomas Vitu¹  Tomas Polcar¹  Frank Schmidl²  Sabine Kellner²  Martin Balzer³  Martin Fenker³  Andreas Richter³ 

[1] Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University in Prague, 16627 Prague, Czech Republic;Low Temperature Physics Group, Institute of Solid State Physics, Friedrich Schiller University Jena, 07743 Jena, Germany;Research Institute for Precious Metals and Metal Chemistry, 73527 Schwäbisch Gmünd, Germany;

关键词: PVD;    HiPIMS;    wear resistant coating;    low friction coatings;    tribology;   

DOI  :  10.3390/coatings11111415

来源: DOAJ

【 摘 要 】

The coating system MoN-Ag is an interesting candidate for industrial applications as a low friction coating at elevated temperatures, due to the formation of lubricous molybdenum oxides and silver molybdates. Film deposition was performed by high-power impulse magnetron sputtering and direct current magnetron sputtering. To facilitate a future transfer to industry Mo-Ag composite targets have been sputtered in Ar/N₂ atmosphere. The chemical composition of the deposited MoN-Ag films has been investigated by wavelength dispersive X-ray spectroscopy. Morphology and crystallographic phases of the films were studied by scanning electron microscopy and X-ray diffraction. To obtain film hardness in relation to Ag content and bias voltage, the instrumented indentation test was applied. Pin-on-disc tribological tests have been performed at room temperature and at high temperature (HT, 450 °C). Samples from HT tests have been analyzed by Raman measurements to identify possible molybdenum oxide and/or silver molybdate phases. At low Ag contents (≤7 at.%), coatings with a hardness of 18–31 GPa could be deposited. Friction coefficients at HT decreased with increasing Ag content. After these tests, Raman measurements revealed the MoO₃ phase on all samples and the Ag₂Mo₄O₁₃ phase for the highest Ag contents (~23–26 at.%).

【 授权许可】

Unknown