Medium ion energy synthesis of hard elastic fullerene-like hydrogenated carbon film with ultra-low friction and wear in humid air

2015 ◽  
Vol 143 ◽  
pp. 188-190 ◽  
Author(s):  
Yongfu Wang ◽  
Junmeng Guo ◽  
Jun Zhao ◽  
Delei Ding ◽  
Yongyong He ◽  
...  
1991 ◽  
Vol 223 ◽  
Author(s):  
Qin Fuguang ◽  
Yao Zhenyu ◽  
Ren Zhizhang ◽  
S.-T. Lee ◽  
I. Bello ◽  
...  

ABSTRACTDirect ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1550 ◽  
Author(s):  
Yunhai Liu ◽  
Lei Chen ◽  
Bin Zhang ◽  
Zhongyue Cao ◽  
Pengfei Shi ◽  
...  

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.


1991 ◽  
Vol 235 ◽  
Author(s):  
D. K. Sood ◽  
V. C. Nath ◽  
Yang Xi

ABSTRACTAmorphisation of sintered SiC by bombardment with self (C, Si) ions has been studied. Ion doses ranged from 1×1015 to 1×1017 ions/cm2; and ion energy was varied from 0.09 to 5 MeV. Amorphisation was detected by micro-focus Raman scattering. Tribomechanical properties-friction and wear were studied with a high precision pin (steel ball) and disc (implanted) machine. Results show substantial improvements in friction and wear, which persist to a large number of cycles. Tribomechanical properties are shown to correlate with surface amorphisation and carburisation. Carbon ions are found to be much more effective than Si ions (with similar damage distributions) in reducing friction and wear.


Friction ◽  
2021 ◽  
Author(s):  
Zonglin Pan ◽  
Qinzhao Zhou ◽  
Pengfei Wang ◽  
Dongfeng Diao

AbstractReducing the friction force between the commercial archwire and bracket during the orthodontic treatment in general dental practice has attracted worldwide interest. An investigation on the friction and wear behaviors of the uncoated and carbon film coated stainless steel archwires running against stainless steel brackets was systematically conducted. The carbon films were prepared at substrate bias voltages from +5 to +50 V using an electron cyclotron resonance plasma sputtering system. With increasing substrate bias voltage, local microstructures of the carbon films evolved from amorphous carbon to graphene nanocrystallites. Both static and stable friction coefficients of the archwire-bracket contacts sliding in dry and wet (artificial saliva) conditions decreased with the deposition of carbon films on the archwires. Low friction coefficient of 0.12 was achieved in artificial saliva environment for the graphene sheets embedded carbon (GSEC) film coated archwire. Deterioration of the friction behavior of the GSEC film coated archwire occurred after immersion of the archwire in artificial saliva solution for different periods before friction test. However, moderate friction coefficient of less than 0.30 sustained after 30 days immersion periods. The low friction mechanism is clarified to be the formation of salivary adsorbed layer and graphene sheets containing tribofilm on the contact interfaces. The robust low friction and low wear performances of the GSEC film coated archwires make them good candidates for clinical orthodontic treatment applications.


2020 ◽  
Vol 507 ◽  
pp. 145040 ◽  
Author(s):  
Ruiyun Li ◽  
Yongfu Wang ◽  
Junyan Zhang ◽  
Ernst Meyer
Keyword(s):  

Friction ◽  
2020 ◽  
Author(s):  
Zelong Hu ◽  
Xue Fan ◽  
Cheng Chen

Abstract sp2 nanocrystallited carbon films with large nanocrystallite sizes, smooth surfaces, and relative high hardness were prepared with different ion irradiation densities regulated with the substrate magnetic coil current in an electron cyclotron resonance plasma sputtering system. Their multiscale frictional behaviors were investigated with macro pin-on-disk tribo-tests and micro nanoscratch tests. The results revealed that, at an ion irradiation density of 16 mA/cm2, sp2 nanocrystallited carbon film exhibits the lowest friction coefficient and good wear resistant properties at both the macroscale and microscale. The film sliding against a Si3N4 ball under a contact pressure of 0.57 GPa exhibited a low friction coefficient of 0.09 and a long wear life at the macroscale. Furthermore, the film sliding against a diamond tip under a contact pressure of 4.9 GPa exhibited a stable low friction coefficient of 0.08 with a shallow scratch depth at the microscale. It is suggested that sp2 nanocrystallites affect the frictional behaviors in the cases described differently. At the macroscale, the contact interface via the small real contact area and the sp2 nanocrystallited transfer layer dominated the frictional behavior, while the sp2 nanocrystallited structure in the film with low shear strength and high plastic resistivity, as well as the smooth surface morphology, decided the steady low nanoscratch properties at the microscale. These findings expand multiscale tribological applications of sp2 nanocrystallited carbon films.


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