Ultra-low friction mechanism of highly sp3-hybridized amorphous carbon controlled by interfacial molecule adsorption

2018 ◽  
Vol 20 (35) ◽  
pp. 22445-22454 ◽  
Author(s):  
Jing Shi ◽  
Tiandong Xia ◽  
Chengbing Wang ◽  
Kun Yuan ◽  
Junyan Zhang
Keyword(s):  
Amorphous Carbon ◽  
Carbon Materials ◽  
Carbon Films ◽  
Nanocrystalline Diamond ◽  
Diamond Like Carbon ◽  
Low Friction ◽  
Friction Mechanism ◽  
Molecule Adsorption

The friction behaviors of highly sp3-hybridized carbon films, including ultra-nanocrystalline diamond and diamond-like carbon materials, strongly depend on atmospheres.

scholarly journals Key Role of Transfer Layer in Load Dependence of Friction on Hydrogenated Diamond-Like Carbon Films in Humid Air and Vacuum

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1550 ◽  
Author(s):  
Yunhai Liu ◽  
Lei Chen ◽  
Bin Zhang ◽  
Zhongyue Cao ◽  
Pengfei Shi ◽  
...  
Keyword(s):  
Applied Load ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Low Friction ◽  
Transfer Layer ◽  
Humid Air ◽  
Friction Mechanism ◽  
Sharp Drop ◽  
Practical Applications ◽  
Load Dependence

The friction of hydrogenated diamond-like carbon (H-DLC) films was evaluated under the controlled environments of humid air and vacuum by varying the applied load. In humid air, there is a threshold applied load below which no obvious friction drop occurs and above which the friction decreases to a relatively low level following the running-in process. By contrast, superlubricity can be realized at low applied loads but easily fails at high applied loads under vacuum conditions. Further analysis indicates that the graphitization of the sliding H-DLC surface has a negligible contribution to the sharp drop of friction during the running-in process under both humid air and vacuum conditions. The low friction in humid air and the superlow friction in vacuum are mainly attributed to the formation and stability of the transfer layer on the counterface, which depend on the load and surrounding environment. These results can help us understand the low-friction mechanism of H-DLC film and define optimized working conditions in practical applications, in which the transfer layer can be maintained for a long time under low applied load conditions in vacuum, whereas a high load can benefit the formation of the transfer layer in humid air.

Low friction mechanism of chlorine-doped amorphous carbon films sliding against an aluminium alloy

2017 ◽  
Vol 115 ◽  
pp. 573-579 ◽  
Author(s):  
Yuuki Tokuta ◽  
Takashi Itoh ◽  
Takahiko Shiozaki ◽  
Masahiro Kawaguchi ◽  
Shinya Sasaki
Keyword(s):  
Aluminium Alloy ◽  
Amorphous Carbon ◽  
Carbon Films ◽  
Low Friction ◽  
Friction Mechanism ◽  
Amorphous Carbon Films

scholarly journals Elastic Constants of Diamond-Like Carbon Films by Surface Brillouin Scattering

1999 ◽  
Vol 593 ◽  
Author(s):  
A.C. Ferrari ◽  
J. Robertson ◽  
R. Pastorelli ◽  
M.G. Beghi ◽  
C.E. Bottani
Keyword(s):  
Thin Films ◽  
Amorphous Carbon ◽  
Elastic Constants ◽  
Acoustic Waves ◽  
Brillouin Scattering ◽  
Surface Acoustic Waves ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Amorphous Carbon Films ◽  
Tetrahedral Amorphous Carbon

ABSTRACTThe elastic constants of thin Diamond-Like Carbon (DLC) films supply important information, but their measurement is difficult. Standard nanoindentation does not directly measure the elastic constants and has strong limitations particularly in the case of hard thin films on softer substrates, such as tetrahedral amorphous carbon on Si. Surface acoustic waves provide a better mean to investigate elastic properties. Surface Brillouin scattering (SBS) intrinsically probes acoustic waves of the wavelength which is appropriate to test the properties of films in the tens to hundreds of nanometers thickness range. SBS can be used to derive all the isotropic elastic constants of hard-on-soft and soft-on-hard amorphous carbon films of different kinds, with thickness down to less than 10 nm. The results help to resolve the previous uncertainties in mechanical data. The Young's modulus of tetrahedral amorphous carbon (ta-C) turns out to be lower than that of diamond, while the moduli of hydrogenated ta-C (ta-C:H) are considerably lower than those of ta-C because of the weakening effect of C-H bonding.

Sign in / Sign up

Export Citation Format

Share Document