Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8024722 | Surface and Coatings Technology | 2017 | 11 Pages |
Abstract
WS2/a-C coatings with various carbon contents (0-65Â at.%) were deposited on silicon wafers by magnetron co-sputtering under different Ar flow rates. Increasing the argon flow rate increases the chemical stoichiometric S/W ratio, but the coating gradually becomes porous and columnar-like. The S/W stoichiometry is less influenced by the variation in carbon concentration. TEM and XRD confirm well crystallized basal (002) planes in the sputter deposited pure WS2 or low-carbon WS2/a-C coatings. The hardness of the composite coatings increases with increasing carbon content or decreasing Ar flow rate. The coating at 40Â at.% C exhibits the highest hardness (10.6Â GPa). Tribotests show that, together with a ultralow wear rate of 10â7Â mm3Â mâ1Â Nâ1, the coefficient of friction can be as low as 0.02 in dry air (5% RH) and around 0.15 in moisture (55% RH) and remains stable within a sliding distance of 1000Â m. The wear resistance is strongly affected by the carbon concentration, deposition pressure and the testing atmospheres.
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Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
Huatang Cao, Jeff Th.M. De Hosson, Yutao Pei,