Thermal stability of sputter deposited nanocrystalline W{sub 2}N/amorphous Si{sub 3}N{sub 4} coatings

Journal Article · Wed Nov 15 04:00:00 EST 2006 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.2353849· OSTI ID:20853797

Fu, T; Shen, Y G; Zhou, Z F; Li, K Y ^[1]

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1. Department of Manufacturing Engineering and Engineering Management, City University of Hong Kong, Kowloon, Hong Kong (China) and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049 (China)

The thermal stability of nanocomposite W-Si-N coatings, which had been sputter deposited at increased silicon target currents, was studied by annealing at 800 or 900 deg. C in vacuum by using x-ray diffraction, x-ray photoelectron spectroscopy, electron probe microanalysis, scanning electron microscopy, atomic force microscopy, and microhardness testing. The crystalline W{sub 2}N coatings were decomposed to W with the loss of interstitial N atoms and the presence of microcracks at their surfaces after annealing at 900 deg. C. The coating consisting of nanocrystalline (nc-) W{sub 2}N imbedded in amorphous (a-) Si{sub 3}N{sub 4} matrices and the amorphous coatings underwent partial recrystallization, the loss of interstitial N atoms, and morphological changes upon annealing. The nc-W{sub 2}N/a-Si{sub 3}N{sub 4} coating had the least N in grain boundaries and the lowest atomic O/N ratio, and it had no failure after annealing at 900 deg. C, showing high thermal stability. The hardness of the coatings was decreased, but the nc-W{sub 2}N/a-Si{sub 3}N{sub 4} coating maintained the highest hardness (46.6{+-}3.7 GPa) after annealing at 900 deg. C.

• OSTI ID: 20853797
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 6 Vol. 24; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
ATOMIC FORCE MICROSCOPY
COATINGS
COMPOSITE MATERIALS
CRYSTALS
ELECTRON MICROPROBE ANALYSIS
GRAIN BOUNDARIES
MICROHARDNESS
MORPHOLOGICAL CHANGES
NANOSTRUCTURES
PRESSURE RANGE GIGA PA
SCANNING ELECTRON MICROSCOPY
SILICON
SILICON NITRIDES
STABILITY
SURFACE COATING
TUNGSTEN COMPOUNDS
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY