Experimental study on friction and wear behaviour of amorphous carbon coatings for mechanical seals in cryogenic environment

2012 ◽  
Vol 258 (24) ◽  
pp. 9531-9535 ◽  
Author(s):  
Jianlei Wang ◽  
Qian Jia ◽  
Xiaoyang Yuan ◽  
Shaopeng Wang
Keyword(s):  
Experimental Study ◽  
Amorphous Carbon ◽  
Friction And Wear ◽  
Wear Behaviour ◽  
Mechanical Seals ◽  
Carbon Coatings ◽  
Amorphous Carbon Coatings

Amorphous Carbon Coatings for Locally Adjusted Tribological Properties in Sheet Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 969-974 ◽  
Author(s):  
Harald Hetzner ◽  
Stephan Tremmel ◽  
Sandro Wartzack
Keyword(s):  
Amorphous Carbon ◽  
Tribological Properties ◽  
Metal Forming ◽  
Friction And Wear ◽  
Wear Properties ◽  
Carbon Coatings ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Friction And Wear Properties ◽  
Amorphous Carbon Coatings

In sheet bulk metal forming, locally adapted friction properties of the contact tool/workpiece are an appropriate means for the targeted enhancement of the material flow, enabling an improved form filling and lowered forming forces. However, the implementation of desirable friction conditions is not trivial. And further, friction is inseparably linked to wear and damage of the contacting surfaces. This calls for a methodological approach in order to consider tribology as a whole already in the early phases of process layout, so that tribological measures which allow fulfilling the requirements concerning local friction and wear properties of the tool surfaces, can already be selected during the conceptual design of the forming tools. Thin tribological coatings are an effective way of improving the friction and wear properties of functional surfaces. Metal-modified amorphous carbon coatings, which are still rather new to the field of metal forming, allow tackling friction and wear simultaneously. Unlike many other types of amorphous carbon, they have the mechanical toughness to be used in sheet bulk metal forming, and at the same time their friction properties can be varied over wide ranges by proper choice of the deposition parameters. Based on concrete research results, the mechanical, structural and special tribological properties of tungsten-modified hydrogenated amorphous carbon coatings (a-C:H:W) are presented and discussed against the background of the tribological requirements of a typical sheet bulk metal forming process.

scholarly journals Amorphous Carbon Coatings for Total Knee Replacements—Part I: Deposition, Cytocompatibility, Chemical and Mechanical Properties

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1952
Author(s):  
Benedict Rothammer ◽  
Kevin Neusser ◽  
Max Marian ◽  
Marcel Bartz ◽  
Sebastian Krauß ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Amorphous Carbon ◽  
Detailed Characterization ◽  
Carbon Coatings ◽  
Dlc Coatings ◽  
Total Knee Replacements ◽  
Knee Replacements ◽  
Total Knee ◽  
Amorphous Carbon Coatings

Diamond-like carbon (DLC) coatings have the potential to reduce implant wear and thus to contribute to avoiding premature failure and increase service life of total knee replacements (TKAs). This two-part study addresses the development of such coatings for ultrahigh molecular weight polyethylene (UHMWPE) tibial inlays as well as cobalt–chromium–molybdenum (CoCr) and titanium (Ti64) alloy femoral components. While a detailed characterization of the tribological behavior is the subject of part II, part I focusses on the deposition of pure (a‑C:H) and tungsten-doped hydrogen-containing amorphous carbon coatings (a‑C:H:W) and the detailed characterization of their chemical, cytological, mechanical and adhesion behavior. The coatings are fabricated by physical vapor deposition (PVD) and display typical DLC morphology and composition, as verified by focused ion beam scanning electron microscopy and Raman spectroscopy. Their roughness is higher than that of the plain substrates. Initial screening with contact angle and surface tension as well as in vitro testing by indirect and direct application indicate favorable cytocompatibility. The DLC coatings feature excellent mechanical properties with a substantial enhancement of indentation hardness and elastic modulus ratios. The adhesion of the coatings as determined in modified scratch tests can be considered as sufficient for the use in TKAs.

scholarly journals PROPERTIES OF NITROGEN-DOPED AMORPHOUS CARBON COATINGS OBTAINED BY IMPULSE VACUUM-ARC METHOD

2018 ◽  
Vol 59 (9) ◽  
pp. 68 ◽  
Author(s):  
Aleksandr I. Poplavskiy ◽  
Aleksandr Ya. Kolpakov ◽  
Marina E. Galkina ◽  
Igor Yu. Goncharov ◽  
Roman A. Lyubushkin ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Carbon Coating ◽  
Vacuum Arc ◽  
Internal Stresses ◽  
Structure And Properties ◽  
Carbon Coatings ◽  
Nitrogen Doped ◽  
Structure Surface ◽  
Amorphous Carbon Coatings ◽  
Carbon Plasma

The paper presents results of the research of the structure and properties of nitrogen-doped amorphous carbon coatings obtained in the vacuum from the flow of pulsed carbon plasma. The doping by nitrogen of carbon coating was determined to lead to increases in electrical conductivity, reductions of internal stresses, reduce of density, hardness and modulus, and to the change in structure, surface morphology and tribological characteristics.

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