Micromechanical Behaviour of Amorphous Hydrogenated Silicon Carbide Films

1993 ◽  
Vol 308 ◽  
Author(s):  
J. Meneve ◽  
R. Jacobs ◽  
F. Lostak ◽  
L. Eersels ◽  
E. Dekempeneer ◽  
...  

ABSTRACTAmorphous hydrogenated silicon carbide (a-Si1-xCx:H) films (x = 0.65 to 1) were deposited by radio frequency plasma assisted chemical vapour deposition (RF-PACVD). Their friction and wear properties were investigated by means of a conventional ball-on-disk apparatus. The results were correlated with film mechanical properties. It was found that adding silicon to a-C:H (also called diamond-like carbon (DLC)) films reduces the hardness, elastic modulus and internal stress values by 15 to 30 %. Scratch testing induces film spallation from stainless steel substrates at low loads (1 N). In the low normal load (1 N) ball-on-disk tests under humid N2 conditions, a-Si1-xCx:H films (0.7 < x < 0.9) combine a very low wear rate of both the film and the counterbody with a steady state low friction coefficient below 0.1. For higher loads (5 and 10 N), however, this low friction coefficient only lasts for a relatively short time. In this case, the harder diamond-like carbon films perform tribologically better because of their higher wear resistance, low wear rate of the counterbody and generally low friction coefficients between 0.15 and 0.35 in a humid ambient atmosphere. In a dry N2 atmosphere, pure DLC films perform tribologically better than a-S1-xCx:H films in all respects.

1990 ◽  
Vol 5 (11) ◽  
pp. 2567-2571 ◽  
Author(s):  
K. Oguri ◽  
T. Arai

Amorphous carbon-silicon (a–C–Si) coatings with smooth surface and adhesion to steel substrate were deposited at 550°C by a dc glow discharge method from reactant gases of CH4, SiCl4, H2, and Ar at a deposition rate of 1–3 μm h−1. Diamond-like carbon was detected by laser Raman spectroscopy in the coatings with high hardness of Hv 2000 and more than 70 at. % carbon. Ball-on-disk type and Ohgoshi-type apparatuses were used to measure the tribological properties. Ball-on-disk tests revealed that the a–C–Si coatings showed a friction coefficient as low as 0.04 against steel with no lubricant in an ambient atmosphere of 70% relative humidity, which was one-third that of an i–C coating. The wear rate of the steel ball against the coated disk was an order and three orders of magnitude smaller than that against i–C coated and uncoated disks, respectively. Both types of tests showed that the wear rate of the a–C–Si coating itself was also very small.


1998 ◽  
Vol 1 (2) ◽  
pp. 81-85
Author(s):  
Clara EE Hanekamp ◽  
Hans JRM Bonnier ◽  
Rolf H Michels ◽  
Kathinka H Peels ◽  
Eric PCM Heijmen ◽  
...  

2003 ◽  
Vol 17 (09) ◽  
pp. 387-392 ◽  
Author(s):  
NIKIFOR RAKOV ◽  
ARSHAD MAHMOOD ◽  
MUFEI XIAO

Amorphous hydrogenated silicon carbide (a-SiC:H) thin films have been prepared by the RF reactive magnetron sputtering technique. The optical properties of the films have been studied by optical spectroscopy with an incoherent light source. The material is commonly regarded as a dielectric. We have discovered however that some films that were prepared under certain deposition conditions and on certain substrates may respond to external light as a metallic thin film, i.e. there are strongly enhanced reflection peaks in the optical spectrum. We have further discovered that some films may have a strong and broadened absorption peak at about 590 nm, which is an apparent photonic bandgap in the visible spectrum. The appearance of the photonic bandgap is very sensitive to two parameters: the substrate and the deposition gas. By changing the two parameters, one shifts the status of the film from with and without the photonic bandgap.


1996 ◽  
Vol 452 ◽  
Author(s):  
U. Klement ◽  
D. Horst ◽  
F. Ernst

AbstractThe objective of this work is to find a material to replace amorphous hydrogenated silicon used as photosensitive part in the “retina” of an “electronic eye”. For that reason, ZnS, ZnSe, CdS and CdSe were chosen for investigations. Thin films, prepared by chemical vapour deposition, were characterized by transmission electron microscopy. The observed microstructures were correlated with the optoelectronic properties of these materials. CdSe was found to be the most promising material for our application. Hence, the influence of a dielectric interlayer and the effects of additional annealing treatments were analyzed for CdSe and will be discussed with respect to the optimization of the material.


Author(s):  
F. Robbe-Valloire ◽  
R. Progri ◽  
B. Paffoni ◽  
R. Gras

Mixed lubrication is usually related to the partition of contacts, and these latter may be divided into two categories. The first includes all asperities working in thin lubricated film (physico-chemical film) conditions. This situation corresponds to local boundary lubrication and is characterised by a local friction coefficient around 0.1. The second category contains all other asperity types. Due to the existence of a thick lubricant films asperities belonging to the second category exhibit a low friction coefficient. The global tribological behaviour for a given contact, however, is function of both categories, since it involves asperities from both categories.


Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
Jarmila Müllerová ◽  
Veronika Vavruňková ◽  
Pavel Å utta

AbstractWe report results obtained from measurements of optical transmittance spectra carried out on a series of silicon thin films deposited by plasma-enhanced chemical vapour deposition (PECVD) from silane diluted with hydrogen. Hydrogen dilution of silane results in an inhomogeneous growth during which the material evolves from amorphous hydrogenated silicon (a-Si:H) to microcrystalline hydrogenated silicon (µc-Si:H). Spectral refractive indices and absorption coefficients were determined from transmittance spectra. The spectral absorption coefficients were used to determine the Tauc optical band gap energy, the B factor of the Tauc plots, E 04 (energy at which the absorption coefficient is equal to 104 cm−1), and the Urbach energy as a function of the hydrogen dilution. The results were correlated with microstructure, namely volume fractions of the amorphous and crystalline phase with voids, and with the grain size.


2009 ◽  
Vol 15 (1-3) ◽  
pp. 39-46 ◽  
Author(s):  
Aleksander M. Wrobel ◽  
Agnieszka Walkiewicz-Pietrzykowska ◽  
Marja Ahola ◽  
I. Juhani Vayrynen ◽  
Francisco J. Ferrer-Fernandez ◽  
...  

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