Structural, mechanical and electrical-contact properties of nanocrystalline-NbC/amorphous-C coatings deposited by magnetron sputtering

SURFACE & COATINGS TECHNOLOGY

卷:206

Article

Nedfors, Nils¹  Tengstrand, Olof²  Lewin, Erik¹  Furlan, Andrej¹  Eklund, Per²  Hultman, Lars²  Jansson, Ulf¹ 

[1] Uppsala Univ, Dept Chem Mat, SE-75235 Uppsala, Sweden

[2] Linkoping Univ, Dept Phys, IFM, SE-58183 Linkoping, Sweden

关键词: Nanocomposite;    Niobium carbide;    Electrical contact properties;    Mechanical properties;    Magnetron sputtering;   

DOI  :  10.1016/j.surfcoat.2011.07.021

来源: Elsevier

【 摘 要 】

Niobium-carbide nanocomposite coatings with a carbon content varying from 43 to 64 at.% were deposited by dual DC magnetron sputtering. X-ray diffraction, x-ray photoelectron spectroscopy and electron microscopy showed that all coatings consisted of nanometer sized NbC grains embedded in a matrix of amorphous carbon. Mechanical properties and electrical resistivity showed a strong dependency on the amount of amorphous carbon (a-C) and NbC grain size in the coating. The highest hardness (23 GPa), elastic modulus (295 GPa) and the lowest resistivity (260 mu Omega cm) were measured for the coating with about 15% of a-C phase. Contact resistance measurements using a crossed cylinder set-up showed lowest contact resistance for the coating containing 33% a-C (140 mu Omega at a contact force of 100 N), which is comparable to a Ag reference (45 mu Omega at a contact force of 100 N). Comparison with TiC-based nanocomposites studied under similar conditions showed that the Nb-C system has less tendency to form a-C and that lowest contact resistance is obtained at comparable amounts of a-C phase in both material systems (33% for Nb-C compared to 35% for Ti-C). With these good electrical contact properties, the Nb- C nanocomposites can be considered as a potential material for electrical contact applications. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

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