Diamond-like carbon (DLC) films have recently been pursued as the protection of MEMS against their friction and wear.Plasma enhanced chemical vapor deposition (PECVD) technique is very attractive to prepare DLC coatin...Diamond-like carbon (DLC) films have recently been pursued as the protection of MEMS against their friction and wear.Plasma enhanced chemical vapor deposition (PECVD) technique is very attractive to prepare DLC coating for MEMS.This paper describes the preparation of DLC films using twinned electron cyclotron resonance (ECR) microwave PECVD process.Raman spectra confirmed the DLC characteristics of the films.Fourier-transform infrared (FT-IR)characterization indicates the carbon is bonded in the form sp~3 and sp~2 with hydrogen participating in bonding.The surface roughness of the films is as low as approximately (0.093)nm measured with an atomic force microscope.A CERT microtribometer system is employed to obtain information about the scratch resistance,friction properties,and sliding wear resistance of the films.The results show the deposited DLC films have low friction and good scratch/wear resistance properties.展开更多
C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation ,...C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ ＋ ion beam- assisted deposition are improved significantly. DLC film produced by C ^＋ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.展开更多
Application of the Langmuir probe in plasma circumstance for deposition of diamond-like carbon （DLC） thin films usually faces the problem of rapid failure of the probe due to surface insulative coating. In this pape...Application of the Langmuir probe in plasma circumstance for deposition of diamond-like carbon （DLC） thin films usually faces the problem of rapid failure of the probe due to surface insulative coating. In this paper, we circumvent the problem by using the floating harmonic probe technique. In the real circumstance of DLC film deposition, the floating harmonic probe worked reliably over 3 hours, correctly indicating the ion density and electron temperature. The technique was practically used to measure the ion density and electron temperature in DLC film deposition processes using the microwave ECR plasma enhanced sputtering. Combined with the Raman spectroscopic characterization of the films, the conditions for deposition of DLC films were investigated.展开更多
DLC super-hard films have been deposited on the substrates of single crystalline Si, pure Ti and stainless steel 18-8 by a method of vacuum cathode arc deposition (VCAD). The composition, microstructure and micro-hard...DLC super-hard films have been deposited on the substrates of single crystalline Si, pure Ti and stainless steel 18-8 by a method of vacuum cathode arc deposition (VCAD). The composition, microstructure and micro-hardness of the films have been studied in this paper. The results indicate that hardness of the DLC films is different on the different substrates. Hardness of the films increases with decreasing in surface roughness of the films. The maximum value of micro-hardness belongs to the DLC films deposited under the hydrogen pressure of 0.35Pa and the negative bias of 100V.展开更多
Abstract Effects of film fragments in the friction system on friction and wear properties of tungsten doped diamond-like carbon films （W-DLC） were studied in the condition of boundary lubrication. It could be observ...Abstract Effects of film fragments in the friction system on friction and wear properties of tungsten doped diamond-like carbon films （W-DLC） were studied in the condition of boundary lubrication. It could be observed that the average friction coefficient was increased after introducing film fragments into the friction system, where these film fragments can accelerate the breaking of the extreme thin oil film which could separate two friction surfaces when the system is under boundary lubrication conditions. The increasing friction load can accelerate the friction ehenfieal reaction on the friction interface and lead to the crushing effect on film fragments, which decreased the friction coefficient of friction system. It was also found that the wear width, depth, and volume of the film increased by introducing film fragments and applying great load.展开更多
A diamond-like carbon（DLC） film was deposited on YT14 substrate using magnetron sputtering（MS）. The surface morphologies, roughness and bonding spectra of obtained film were characterized using scanning electron m...A diamond-like carbon（DLC） film was deposited on YT14 substrate using magnetron sputtering（MS）. The surface morphologies, roughness and bonding spectra of obtained film were characterized using scanning electron microscopy（SEM）, atomic force microscopy（AFM）, and X-ray photoelectron spectroscopy（XPS）, respectively, and its mechanical property and bonding strength were measured using a nanoindentation and scratch tester, respectively. The results show that the C-enriched DLC film exhibits a denser microstructure and smoother surface with lower surface roughness of 21.8 nm. The ratio of C sp2 at 284.4 e V that corresponds to the diamond（111） and the C sp3 at 285.3 e V that corresponds to the diamond（220） plane for the as-received film is 0.36： 0.64, showing that the C sp3 has the high content. The hardness and Young＇s modulus of DLC film by nanoindentation are 8.534 41 and 142.158 1 GPa, respectively, and the corresponding bonding strength is 74.55 N by scratch test.展开更多
Diamond-like carbon (DLC) films were prepared by PLD process using 308 nm(XeCl) laser beam with high power (500 W) and high frequency(300 Hz). The effects of nitrogen pressure on the structure and properties of the DL...Diamond-like carbon (DLC) films were prepared by PLD process using 308 nm(XeCl) laser beam with high power (500 W) and high frequency(300 Hz). The effects of nitrogen pressure on the structure and properties of the DLC films under such extremely high power and repetition rate were studied. The results indicate that the microstructures of the films are varied from amorphous carbon to graphitized carbon in long-order with the increase of N2 pressure, and the optical properties of the films are deteriorated as compared to that of DLC films without nitrogen.展开更多
Composite SiNx/DLC films were deposited on Si substrate by RF magnetron sputtering of silicon nitride (Si3N4) target simultaneously with filtered cathode arc (FCA) of graphite. The RF power was fixed at 100 W whereas ...Composite SiNx/DLC films were deposited on Si substrate by RF magnetron sputtering of silicon nitride (Si3N4) target simultaneously with filtered cathode arc (FCA) of graphite. The RF power was fixed at 100 W whereas the arc currents of FCA were 20, 40, 60 and 80 A. The effects of arc current on the structure, surface roughness, density and mechanical properties of SiNx/DLC films were investigated. The results show that the arc current in the studied range has effect on the structure, surface roughness, density and mechanical properties of composite SiNx/DLC films. The composite SiNx/DLC films show the sp3 content between 53.5% and 66.7%, density between 2.54 and2.98 g/cm3, stress between 1.7 and 2.2 GPa, and hardness between 35 and 51 GPa. Furthermore, it was found that the density, stress and hardness correlate linearly with the sp3 content for composite SiNx/DLC films.展开更多
Nano-diamond like carbon（DLC） thin films were prepared on fused silica and Cu substrates by the pulsed-laser deposition technique with different laser intensities. Step-measurement, atomic force microscope（AFM）, U...Nano-diamond like carbon（DLC） thin films were prepared on fused silica and Cu substrates by the pulsed-laser deposition technique with different laser intensities. Step-measurement, atomic force microscope（AFM）, UV-VIS-NIR transmittance spectroscopy and Raman spectroscopy were used to characterize the films. It was shown that the deposition rate increases with the laser intensity, and the films prepared under different laser intensities show different transparency. Raman measurement showed that the content of sp^3 of the Nano-DLC thin films decreases with the laser intensity. The field emission properties of the Nano-DLC thin films on Cu substrates were studied by the conventional diode method, which showed that the turn-on field increases and the current density decreases with sp^3 content in the films. A lower turn-on field of 6 V/um and a higher current density of 1 uA/cm^2 were obtained for Nano-DLC thin films on Cu substrate.展开更多
Diamond like carbon(DLC)films with different C-C sp2/sp3 ratios were prepared by tuning the N2 flow rate in a filtered cathodic vacuum arc(FCVA)system.The increase of N2 flow rate facilitated the increase of C-C sp2/s...Diamond like carbon(DLC)films with different C-C sp2/sp3 ratios were prepared by tuning the N2 flow rate in a filtered cathodic vacuum arc(FCVA)system.The increase of N2 flow rate facilitated the increase of C-C sp2/sp3 ratio(1.09-2.66),the growth of particle size(0.78-1.58 nm)and the improvement of surface roughness.The SBF immersion results,as well as WCAs(77.57°~71.71°),hemolysis rate(0.14-1.00%)and cytotoxicity level(0)demonstrated that the as-fabricated DLC film was promising for biomedical application.As a result of surface charge effect,the apatite layers formed in the SBF increased with the increase of C-C sp2/sp3 ratio until 1.74 and then showed a tiny decrease during 1.74-2.66.A raise of hemolysis and cytotoxicity was observed when sp2/sp3 ratio was increased.Moreover,a decrease of friction coefficient of Si surface induced by increasing sp2/sp3 ratio was respectively evidenced in ambient air and SBF lubrication environments.展开更多
The Ti C→DLC gradient composite films were characterized systematically. The elemental depth profile and elemental chemical state evolution were determined by X ray photoelectron spectroscopy (XPS). The transmission ...The Ti C→DLC gradient composite films were characterized systematically. The elemental depth profile and elemental chemical state evolution were determined by X ray photoelectron spectroscopy (XPS). The transmission electron microscope (TEM) and high resolution transmission electron microscopy (HRTEM) were used to study the structure of interfacial zone between DLC film and Ti C layers. Results show that there are composition transition zone between DLC film and either Ti C layer or steel substrate on condition that pre deposited Ti layers on the steel substrate then plasma based bias deposited DLC films. In Ti C graded layer, the chemical state of titanium and carbon are changed gradually. The structures of zone in Ti C layer near the DLC film is consisted of random oriented nanocrystallines TiC dispersed in amorphous DLC matrix. The structure of the zone between DLC film and Ti C graded layer is gradually changed too.展开更多
The carbon films are prepared by r.f. plasma method with n butylamine as carbon source. The analysis of Raman spectrosecopy shows that this kind of carbon film has diamond_like structure, and IR spectroscopy measureme...The carbon films are prepared by r.f. plasma method with n butylamine as carbon source. The analysis of Raman spectrosecopy shows that this kind of carbon film has diamond_like structure, and IR spectroscopy measurement indicats that there are SP 2 bonding, SP 3 bonding and amino group in the film. It is the existence of amino group and hydrogen atom that cause the amorphous structure and the deformation of bonding to increase, thus leading the Raman spectrum to form a broad absorption band. The quartz crystal microbalance (QCM) deposited with this kind of carbon film as recognizing coating is very sensitive to formic acid vapors. This QCM sensor has good reproducibility, high stability, rapid response and long lifetime.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 50972078 and 51002090)the Outstanding Young Scientist Research Award Fund of Shandong Province (No. BS2010CL028)
文摘Diamond-like carbon (DLC) films have recently been pursued as the protection of MEMS against their friction and wear.Plasma enhanced chemical vapor deposition (PECVD) technique is very attractive to prepare DLC coating for MEMS.This paper describes the preparation of DLC films using twinned electron cyclotron resonance (ECR) microwave PECVD process.Raman spectra confirmed the DLC characteristics of the films.Fourier-transform infrared (FT-IR)characterization indicates the carbon is bonded in the form sp~3 and sp~2 with hydrogen participating in bonding.The surface roughness of the films is as low as approximately (0.093)nm measured with an atomic force microscope.A CERT microtribometer system is employed to obtain information about the scratch resistance,friction properties,and sliding wear resistance of the films.The results show the deposited DLC films have low friction and good scratch/wear resistance properties.
基金Funded by the National Natural Science Foundation of China(No.50175041 ,50275111)
文摘C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ ＋ ion beam- assisted deposition are improved significantly. DLC film produced by C ^＋ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.
文摘Application of the Langmuir probe in plasma circumstance for deposition of diamond-like carbon （DLC） thin films usually faces the problem of rapid failure of the probe due to surface insulative coating. In this paper, we circumvent the problem by using the floating harmonic probe technique. In the real circumstance of DLC film deposition, the floating harmonic probe worked reliably over 3 hours, correctly indicating the ion density and electron temperature. The technique was practically used to measure the ion density and electron temperature in DLC film deposition processes using the microwave ECR plasma enhanced sputtering. Combined with the Raman spectroscopic characterization of the films, the conditions for deposition of DLC films were investigated.
基金This work was supported by the Natural Science Foundation of Guangdong Province(990548)the Special Project for PhD Subject of the Education Ministry of China(1999056121)+1 种基金the Key Project of the Guangdong Provincial Nano-Materials Science&Technology Program(2001A1060404)the Key Project of the Guangdong Provincial Science&Technology Program(2KM00407G).
文摘DLC super-hard films have been deposited on the substrates of single crystalline Si, pure Ti and stainless steel 18-8 by a method of vacuum cathode arc deposition (VCAD). The composition, microstructure and micro-hardness of the films have been studied in this paper. The results indicate that hardness of the DLC films is different on the different substrates. Hardness of the films increases with decreasing in surface roughness of the films. The maximum value of micro-hardness belongs to the DLC films deposited under the hydrogen pressure of 0.35Pa and the negative bias of 100V.
基金supported by China National Machinery Industry Group(Grant No.SINOMACH 2017 246)
文摘Abstract Effects of film fragments in the friction system on friction and wear properties of tungsten doped diamond-like carbon films （W-DLC） were studied in the condition of boundary lubrication. It could be observed that the average friction coefficient was increased after introducing film fragments into the friction system, where these film fragments can accelerate the breaking of the extreme thin oil film which could separate two friction surfaces when the system is under boundary lubrication conditions. The increasing friction load can accelerate the friction ehenfieal reaction on the friction interface and lead to the crushing effect on film fragments, which decreased the friction coefficient of friction system. It was also found that the wear width, depth, and volume of the film increased by introducing film fragments and applying great load.
基金Funded by the Jiangsu Province Science and Technology Support Program(Industry)(No.BE2014818)
文摘A diamond-like carbon（DLC） film was deposited on YT14 substrate using magnetron sputtering（MS）. The surface morphologies, roughness and bonding spectra of obtained film were characterized using scanning electron microscopy（SEM）, atomic force microscopy（AFM）, and X-ray photoelectron spectroscopy（XPS）, respectively, and its mechanical property and bonding strength were measured using a nanoindentation and scratch tester, respectively. The results show that the C-enriched DLC film exhibits a denser microstructure and smoother surface with lower surface roughness of 21.8 nm. The ratio of C sp2 at 284.4 e V that corresponds to the diamond（111） and the C sp3 at 285.3 e V that corresponds to the diamond（220） plane for the as-received film is 0.36： 0.64, showing that the C sp3 has the high content. The hardness and Young＇s modulus of DLC film by nanoindentation are 8.534 41 and 142.158 1 GPa, respectively, and the corresponding bonding strength is 74.55 N by scratch test.
文摘Diamond-like carbon (DLC) films were prepared by PLD process using 308 nm(XeCl) laser beam with high power (500 W) and high frequency(300 Hz). The effects of nitrogen pressure on the structure and properties of the DLC films under such extremely high power and repetition rate were studied. The results indicate that the microstructures of the films are varied from amorphous carbon to graphitized carbon in long-order with the increase of N2 pressure, and the optical properties of the films are deteriorated as compared to that of DLC films without nitrogen.
文摘Composite SiNx/DLC films were deposited on Si substrate by RF magnetron sputtering of silicon nitride (Si3N4) target simultaneously with filtered cathode arc (FCA) of graphite. The RF power was fixed at 100 W whereas the arc currents of FCA were 20, 40, 60 and 80 A. The effects of arc current on the structure, surface roughness, density and mechanical properties of SiNx/DLC films were investigated. The results show that the arc current in the studied range has effect on the structure, surface roughness, density and mechanical properties of composite SiNx/DLC films. The composite SiNx/DLC films show the sp3 content between 53.5% and 66.7%, density between 2.54 and2.98 g/cm3, stress between 1.7 and 2.2 GPa, and hardness between 35 and 51 GPa. Furthermore, it was found that the density, stress and hardness correlate linearly with the sp3 content for composite SiNx/DLC films.
文摘Nano-diamond like carbon（DLC） thin films were prepared on fused silica and Cu substrates by the pulsed-laser deposition technique with different laser intensities. Step-measurement, atomic force microscope（AFM）, UV-VIS-NIR transmittance spectroscopy and Raman spectroscopy were used to characterize the films. It was shown that the deposition rate increases with the laser intensity, and the films prepared under different laser intensities show different transparency. Raman measurement showed that the content of sp^3 of the Nano-DLC thin films decreases with the laser intensity. The field emission properties of the Nano-DLC thin films on Cu substrates were studied by the conventional diode method, which showed that the turn-on field increases and the current density decreases with sp^3 content in the films. A lower turn-on field of 6 V/um and a higher current density of 1 uA/cm^2 were obtained for Nano-DLC thin films on Cu substrate.
基金support from National Natural Science Foundation of China(Grant 51801164)Besides,this work is jointly supported by Fundamental Research Funds for the Central Universities(Grant XDJK2020C005)+1 种基金National Training Program of Innovation and Entrepreneurship for Undergraduates(Grant 201810635068)the Venture&Innovation Support Program for Chongqing Overseas Returnees(Grant cx2018080).
文摘Diamond like carbon(DLC)films with different C-C sp2/sp3 ratios were prepared by tuning the N2 flow rate in a filtered cathodic vacuum arc(FCVA)system.The increase of N2 flow rate facilitated the increase of C-C sp2/sp3 ratio(1.09-2.66),the growth of particle size(0.78-1.58 nm)and the improvement of surface roughness.The SBF immersion results,as well as WCAs(77.57°~71.71°),hemolysis rate(0.14-1.00%)and cytotoxicity level(0)demonstrated that the as-fabricated DLC film was promising for biomedical application.As a result of surface charge effect,the apatite layers formed in the SBF increased with the increase of C-C sp2/sp3 ratio until 1.74 and then showed a tiny decrease during 1.74-2.66.A raise of hemolysis and cytotoxicity was observed when sp2/sp3 ratio was increased.Moreover,a decrease of friction coefficient of Si surface induced by increasing sp2/sp3 ratio was respectively evidenced in ambient air and SBF lubrication environments.
文摘The Ti C→DLC gradient composite films were characterized systematically. The elemental depth profile and elemental chemical state evolution were determined by X ray photoelectron spectroscopy (XPS). The transmission electron microscope (TEM) and high resolution transmission electron microscopy (HRTEM) were used to study the structure of interfacial zone between DLC film and Ti C layers. Results show that there are composition transition zone between DLC film and either Ti C layer or steel substrate on condition that pre deposited Ti layers on the steel substrate then plasma based bias deposited DLC films. In Ti C graded layer, the chemical state of titanium and carbon are changed gradually. The structures of zone in Ti C layer near the DLC film is consisted of random oriented nanocrystallines TiC dispersed in amorphous DLC matrix. The structure of the zone between DLC film and Ti C graded layer is gradually changed too.
文摘The carbon films are prepared by r.f. plasma method with n butylamine as carbon source. The analysis of Raman spectrosecopy shows that this kind of carbon film has diamond_like structure, and IR spectroscopy measurement indicats that there are SP 2 bonding, SP 3 bonding and amino group in the film. It is the existence of amino group and hydrogen atom that cause the amorphous structure and the deformation of bonding to increase, thus leading the Raman spectrum to form a broad absorption band. The quartz crystal microbalance (QCM) deposited with this kind of carbon film as recognizing coating is very sensitive to formic acid vapors. This QCM sensor has good reproducibility, high stability, rapid response and long lifetime.
