In this work, diamond-like carbon （DLC） films were deposited on stainless steel substrates with Si/SiC intermediate layers by combining plasma enhanced sputtering physical vapour deposition （PEUMS-PVD） and microwa...In this work, diamond-like carbon （DLC） films were deposited on stainless steel substrates with Si/SiC intermediate layers by combining plasma enhanced sputtering physical vapour deposition （PEUMS-PVD） and microwave electron cyclotron resonance plasma enhanced chemical vapour deposition （MW-ECRPECVD） techniques. The influence of substrate negative self-bias voltage and Si target power on the structure and nano-mechanical behaviour of the DLC films were investigated by Raman spectroscopy, nano-indentation, and the film structural morphology by atomic force microscopy （AFM）. With the increase of deposition bias voltage, the G band shifted to higher wave-number and the integrated intensity ratio ID/IG increased. We considered these as evidences for the development of graphitization in the films. As the substrate negative self-bias voltage increased, particle bombardment function was enhanced and the sp^3-bond carbon density reducing, resulted in the peak values of hardness （H） and elastic modulus （E）. Silicon addition promoted the formation of sp^3 bonding and reduced the hardness. The incorporated Si atoms substituted sp^2- bond carbon atoms in ring structures, which promoted the formation of sp^3-bond. The structural transition from C-C to C-Si bonds resulted in relaxation of the residual stress which led to the decrease of internal stress and hardness. The results of AFM indicated that the films was dense and homogeneous, the roughness of the films was decreased due to the increase of substrate negative self-bias voltage and the Si target power.展开更多
By depositing diamond like carbon (DLC) film with radio frequency plasma chemical vapor deposition (RFPCVD) method, a new surface passivation technique for photoluminescence porous silicon (PS) has been studied. The s...By depositing diamond like carbon (DLC) film with radio frequency plasma chemical vapor deposition (RFPCVD) method, a new surface passivation technique for photoluminescence porous silicon (PS) has been studied. The surface microstructure and photoelectric properties of both porous silicon and DLC coated PS have been analyzed by using AFM, FTIR and PL spectrotrieters. The results show the DLC film with dense and homogenous nanometer grains can be deposited on the PS used as passivation coating as it can terminate oxide reaction on the surface of the PS. Furthermore, certain ratio of hydrogen existed in the DLC film can be improved to form hydride species on the DLC/PS interface as the centers of the luminescence so that the DLC coating is of benefit not only to the passivation of the PS but also to the improvement of its luminescent intensity.展开更多
Diamond-like carbon （DLC） films was deposited successfully on stainless steel sub- strates with Si/SiC intermediate layers by combining plasma enhanced unbalanced magnetron sputtering physical vapor deposition （PEU...Diamond-like carbon （DLC） films was deposited successfully on stainless steel sub- strates with Si/SiC intermediate layers by combining plasma enhanced unbalanced magnetron sputtering physical vapor deposition （PEUMS-PVD） and microwave electron cyclotron resonance plasma enhanced chemical vapor deposition （MW-ECR PECVD） techniques. The effect of sil- icon dopant on the structure, morphology, nanomechanical properties and electrochemical be- havior of DLC films were investigated by Raman spectroscopy, nano-indentation, atomic force microscopy （AFM） and potentiodynamic method and electrochemical impedance spectroscopy （EIS）. It showed that the incorporated silicon atoms substituted sp2-bonded carbon atoms in the ring structures, promoting the formation of sp3-bonds. The structural transition from C-C to C-Si bonds resulted in the relaxation of the residual stress, leading to the decrease in films hardness. The DLC films with Si/SiC intermediate layers led to significant improvement in the corrosion resistance of the stainless steel substrate due to effective isolation and good chemical inertness of the DLC films.展开更多
TiC-containing diamond-like carbon （TiC-DLC） nanocomposite coatings were deposited by a rectangular cathodic arc ion-plating system using C2H2 as reacting gas. Raman spectroscopy and transmission electron microscopy...TiC-containing diamond-like carbon （TiC-DLC） nanocomposite coatings were deposited by a rectangular cathodic arc ion-plating system using C2H2 as reacting gas. Raman spectroscopy and transmission electron microscopy analysis show that with increasing flow rate of C2H2, the structure of nanocomposite coatings changes from TiC nanograin-containing to graphite nanograin-containing DLC. The harness measurements show that the hardness decreases from 28 GPa to 18 GPa with increasing C2H2 flow rate. The scratch test show that a high critical load （〉40 N） was obtained and exhibited a good adhesion between the coating and the substrate. Wear experiment shows that the friction coefficient of TiC-DLC nanocomposite coatings decreases with increasing C2H2. A low friction coefficient of 0.07 was obtained at 480 sccm C2H2.展开更多
Diamond-like carbon (DLC) films are deposited on quartz substrate using pure CH4 in the surface wave plasma equipment. A direct current negative bias up to -90 V is applied to the substrate to investigate the bias eff...Diamond-like carbon (DLC) films are deposited on quartz substrate using pure CH4 in the surface wave plasma equipment. A direct current negative bias up to -90 V is applied to the substrate to investigate the bias effect on the film characteristics. Deposited films are characterized by Raman spectroscopy, infrared (IR) and ultraviolet-visible absorption techniques. There are two broad Raman peaks around 1340 cm-1 and 1600 cm-1 and the first one has a greater sp3 component with an increased bias. Infrared spectroscopy has three sp3 C-H modes at 2852 cm-1, 2926 cm-1 and 2962 cm-1, respectively and also shows an intensity increase with the negative bias. Optical band gap is calculated from the ultraviolet-visible absorption spectroscopy and the increased values with negative bias and deposition time are obtained. After a thermal anneal at about 500℃ for an hour to the film deposited under the bias of-90 V, we get an almost unchanged Raman spectrum and a peak intensity-reduced IR signal, which indicates a reduced H-content in the film. Meanwhile the optical band gap changed from 0.85 eV to 1.5 eV.展开更多
围绕压阻传感器领域对高性能类金刚石(Diamond Like Carbon,DLC)薄膜压阻敏感材料的需求,针对金属掺杂DLC存在的载流子输运行为和实际多工况(如温度、湿度等)下压阻性能不明的问题,本工作以Ti-石墨复合拼接靶为靶材,采用高功率脉冲磁控...围绕压阻传感器领域对高性能类金刚石(Diamond Like Carbon,DLC)薄膜压阻敏感材料的需求,针对金属掺杂DLC存在的载流子输运行为和实际多工况(如温度、湿度等)下压阻性能不明的问题,本工作以Ti-石墨复合拼接靶为靶材,采用高功率脉冲磁控溅射技术,高通量制备出4种Ti含量(原子分数为0.43%~4.11%)的Ti掺杂类金刚石(Ti-DLC)薄膜,研究了Ti含量对薄膜组分结构、电学性能、变湿度环境下压阻性能的影响规律。结果表明:Ti含量(原子分数)在0.43%~4.11%范围内,掺杂Ti原子均以固溶形式均匀镶嵌于非晶碳网络中,Ti-DLC薄膜电学行为表现为典型半导体特性,在200~350 K温度范围内,薄膜电阻率均随温度升高而降低。载流子传导机制在200~270 K内为Mott型三维变程跳跃传导,在270~350 K范围内则为热激活传导。Ti-DLC薄膜压阻系数(Gauge Factor,GF)最大值为95.1,在20%~80%相对湿度范围内,所有样品GF均随湿度增加而增大,这可能是引入的固溶Ti原子缩短了导电相之间的平均距离,同时吸附表面水分子导致电阻变化。展开更多
目的研究硅(Si)、氧(O)元素掺杂对类金刚石(Diamond like Carbon,DLC)薄膜沉积、结构、表面形貌以及阻隔性能的影响,为高效制备高阻隔硅氧共掺类金刚石(Si and O Incorporated DLC,Si/O-DLC)薄膜提供新的思路参考。方法利用微波等离子...目的研究硅(Si)、氧(O)元素掺杂对类金刚石(Diamond like Carbon,DLC)薄膜沉积、结构、表面形貌以及阻隔性能的影响,为高效制备高阻隔硅氧共掺类金刚石(Si and O Incorporated DLC,Si/O-DLC)薄膜提供新的思路参考。方法利用微波等离子体化学气相沉积(Plasma Enhanced Chemical Vapor Deposition,PECVD)技术在聚对苯二甲酸乙二醇酯(Polyethylene terephthalate,PET)基底表面沉积Si/O-DLC薄膜,具体研究反应单体中六甲基二硅氧烷(Hexaethyldisiloxane,HMDSO)含量对薄膜沉积和阻隔性能的影响。通过台阶仪、傅里叶红外光谱(FTIR)、X射线光电子能谱(XPS)、原子力显微镜(AFM)表征薄膜厚度、结构和微观形貌,并通过测试氧气透过率表征复合薄膜的阻隔性能。结果随着混合气体中HMDSO含量增加,薄膜的沉积速率提高,不同高度位置上沉积速率波动变弱,平均沉积速率最高达到310 nm·min^(–1),同时,薄膜中Si、O元素含量增加,相关的键合结构含量增加,薄膜表面致密性变差,氧气阻隔性能变弱;当HMDSO流量控制在1 mL·min^(–1)时,PET薄膜的氧气透过率可从未涂覆时的132mL·m^(2)·d^(–1)降低至2mL·m^(2)·d^(-1),阻隔性能明显改善。结论在一定工艺条件下,通过微波PECVD技术在PET薄膜表面涂覆Si/O-DLC薄膜,可明显改善其阻隔性能。展开更多
The effects of surface adsorption of bovine serum albumin(BSA) and human gamma-globulin(HGG) on the tribological performance of a DLC film were investigated using a quartz crystal microbalance with dissipation(QCM-D),...The effects of surface adsorption of bovine serum albumin(BSA) and human gamma-globulin(HGG) on the tribological performance of a DLC film were investigated using a quartz crystal microbalance with dissipation(QCM-D), a ball-on-disk reciprocating tribometer, and a three-electrode electrochemical cell. The results showed that the wear depth in the BSA solution was higher than that in the HGG solution. In the HGG solution, the HGG-adsorbed layer could act as a lubricating layer and protect the DLC film from wear. The wear volume of DLC film in BSA and HGG mixture solution was higher than that in single HGG solution. This may be because the BSA molecules inhibit the formation of HGG adsorbed layer during sliding.展开更多
The frictional resistance and machining quality when cutting carbon fiber reinforced plastics (CFRP) laminates are associated with tribological behavior of tool materials. In the present study, the tribological proper...The frictional resistance and machining quality when cutting carbon fiber reinforced plastics (CFRP) laminates are associated with tribological behavior of tool materials. In the present study, the tribological properties of three types of monolayer microcrystalline diamond (MCD) coatings, nanocrystalline diamond (NCD) coatings and dual-layer MCD/NCD coatings sliding against CFRP are investigated under dry lubricated conditions using the rotational friction tester. The coefficients of friction (COF), wear rate and worn surfaces of the contacted surfaces are analyzed for the MCD-CFRP, NCD-CFRP and MCD/NCD-CFRP contacting pairs. The results show that compared with the monolayer MCD and NCD, the bilayer of MCD/NCD coating displays the lowest COF with the value of ~0.13, it is 42% and 55% of the values for MCD and NCD coatings. Due to the rough surfaces of MCD, the wear debris of CFRP on MCD samples exhibits the plowing effect. While for the NCD and MCD/NCD samples, the wear fragments display the planar shapes. The wear rate of CFRP against MCD is more than twice that of CFRP against NCD, due to the excellent loading capacity. While the wear rate of CFRP against MCD/NCD is about twice than that of CFRP-NCD pairs. The bilayer of MCD/NCD combines the excellent advantages of high hardness of MCD and the smooth surface of NCD. It shows the broad application potential for the bilayer coatings.展开更多
A unique diamond-like carbon (DLC) grinding wheel was developed, in which the DLC fibres were made by rolling Al sheets coated with DLC films and aligned no rmally to the grinding wheel surface by laminating Al sheets...A unique diamond-like carbon (DLC) grinding wheel was developed, in which the DLC fibres were made by rolling Al sheets coated with DLC films and aligned no rmally to the grinding wheel surface by laminating Al sheets together with DLC fibres. In this paper, the formation process of DLC fibres and the fabrication process of a DLC fibre wheel were investigated. Many grinding experiments were also carried out on a precision NC plane milling machine using a newly developed DLC wheel. Grinding of specimens of silicon wafers, optical glasses, quartz, granites and hardened die steel SKD11 demonstrated the capabilities of nanometer surface finish. A smooth surface with a roughness value of Ra2.5 nm (Ry26 nm) was achieved.展开更多
Fe ions in the fluence range of 2×1015 to 1×1017 cm-2 were implanted into diamond-like carbon (DLC) thin film of 100 nm thick, which were deposited on silicon substrate by plasma enhanced chemical vapor depo...Fe ions in the fluence range of 2×1015 to 1×1017 cm-2 were implanted into diamond-like carbon (DLC) thin film of 100 nm thick, which were deposited on silicon substrate by plasma enhanced chemical vapor deposition. Effects of Fe ion implantation on microstructure and friction coefficient of the DLC were studied. With increasing Fe ion fluence, friction coefficient of the DLC film increased as compared with that of DLC without implantation, and then decreased. The Raman spectra characteristics also show a dependence on the Fe ion fluence. With increasing the ion fluence, the sp2 bonding increased in the DLC film, resulting in the decrease of friction coefficient of the film af- ter implantation. Substantial surface roughness was also measured.展开更多
The friction, wear and lubrication of carbon nitride coatings on silicon substrates are studied using a spherical diamond counter-face with nano-scale asperities. The first part of this paper clarifies the coating thi...The friction, wear and lubrication of carbon nitride coatings on silicon substrates are studied using a spherical diamond counter-face with nano-scale asperities. The first part of this paper clarifies the coating thickness effect on factional behavior of carbon nitride coatings. The second part of this paper reports empirical data on wear properties in repeated sliding contacts through in situ examination and post-sliding observation. The third part will concentrate on wear mechanisms for the transition from "No observable wear particles" to "Wear particle generation." In light of the above tribological study, the application of carbon nitride coatings to MicroElectroMechanical system (MEMS) is therefore discussed from view points of both microtribology and micromachining.展开更多
Organic molybdenum lubricant additive like molybdenum dialkyl dithiocarbamate(MoDTC)can cause wear acceleration of diamond-like carbon(DLC)coating coupled with steel under boundary lubrication,which hinders its indust...Organic molybdenum lubricant additive like molybdenum dialkyl dithiocarbamate(MoDTC)can cause wear acceleration of diamond-like carbon(DLC)coating coupled with steel under boundary lubrication,which hinders its industrial application.Therefore,polyisobutylene succinimide(PIBS),an organo molybdenum amide,was adopted to modify molybdenum oxide affording molybdenum polyisobutylene succinimidemolybdenum oxide nanoparticles(MPIBS-MONPs)with potential to prevent the wear acceleration of DLC coating.The thermal stability of MPIBS-MONPs was evaluated by thermogravimetric analysis.Their tribological properties as the additives in di-isooctyl sebacate(DIOS)were evaluated with MoDTC as a control;and their tribomechanism was investigated in relation to their tribochemical reactions and synergistic tribological effect with zinc dialkyldithiophosphate(ZDDP)as well as worn surface characterizations.Findings indicate that MPIBS-MONPs/ZDDP added in DIOS can significantly reduce the friction and wear of DLC coating,being much superior to MoDTC.This is because MPIBS-MONPs and ZDDP jointly take part in tribochemical reactions to form a composite tribofilm that can increase the wear resistance of DLC coating.Namely,the molybdenum amide on MPIBS-MONPs surface can react with ZDDP to form MoS2 film with excellent friction-reducing ability;and MPIBS-MONPs can release molybdenum oxide nanoparticle to form deposited lubrication layer on worn surfaces.The as-formed composite tribofilm consisting of molybdenum oxide nanocrystal,amorphous polyphosphate,and molybdenum disulfide as well as a small amount of Mo2C accounts for the increase in the wear resistance of DLC coating under boundary lubrication.展开更多
文摘In this work, diamond-like carbon （DLC） films were deposited on stainless steel substrates with Si/SiC intermediate layers by combining plasma enhanced sputtering physical vapour deposition （PEUMS-PVD） and microwave electron cyclotron resonance plasma enhanced chemical vapour deposition （MW-ECRPECVD） techniques. The influence of substrate negative self-bias voltage and Si target power on the structure and nano-mechanical behaviour of the DLC films were investigated by Raman spectroscopy, nano-indentation, and the film structural morphology by atomic force microscopy （AFM）. With the increase of deposition bias voltage, the G band shifted to higher wave-number and the integrated intensity ratio ID/IG increased. We considered these as evidences for the development of graphitization in the films. As the substrate negative self-bias voltage increased, particle bombardment function was enhanced and the sp^3-bond carbon density reducing, resulted in the peak values of hardness （H） and elastic modulus （E）. Silicon addition promoted the formation of sp^3 bonding and reduced the hardness. The incorporated Si atoms substituted sp^2- bond carbon atoms in ring structures, which promoted the formation of sp^3-bond. The structural transition from C-C to C-Si bonds resulted in relaxation of the residual stress which led to the decrease of internal stress and hardness. The results of AFM indicated that the films was dense and homogeneous, the roughness of the films was decreased due to the increase of substrate negative self-bias voltage and the Si target power.
文摘By depositing diamond like carbon (DLC) film with radio frequency plasma chemical vapor deposition (RFPCVD) method, a new surface passivation technique for photoluminescence porous silicon (PS) has been studied. The surface microstructure and photoelectric properties of both porous silicon and DLC coated PS have been analyzed by using AFM, FTIR and PL spectrotrieters. The results show the DLC film with dense and homogenous nanometer grains can be deposited on the PS used as passivation coating as it can terminate oxide reaction on the surface of the PS. Furthermore, certain ratio of hydrogen existed in the DLC film can be improved to form hydride species on the DLC/PS interface as the centers of the luminescence so that the DLC coating is of benefit not only to the passivation of the PS but also to the improvement of its luminescent intensity.
文摘Diamond-like carbon （DLC） films was deposited successfully on stainless steel sub- strates with Si/SiC intermediate layers by combining plasma enhanced unbalanced magnetron sputtering physical vapor deposition （PEUMS-PVD） and microwave electron cyclotron resonance plasma enhanced chemical vapor deposition （MW-ECR PECVD） techniques. The effect of sil- icon dopant on the structure, morphology, nanomechanical properties and electrochemical be- havior of DLC films were investigated by Raman spectroscopy, nano-indentation, atomic force microscopy （AFM） and potentiodynamic method and electrochemical impedance spectroscopy （EIS）. It showed that the incorporated silicon atoms substituted sp2-bonded carbon atoms in the ring structures, promoting the formation of sp3-bonds. The structural transition from C-C to C-Si bonds resulted in the relaxation of the residual stress, leading to the decrease in films hardness. The DLC films with Si/SiC intermediate layers led to significant improvement in the corrosion resistance of the stainless steel substrate due to effective isolation and good chemical inertness of the DLC films.
文摘TiC-containing diamond-like carbon （TiC-DLC） nanocomposite coatings were deposited by a rectangular cathodic arc ion-plating system using C2H2 as reacting gas. Raman spectroscopy and transmission electron microscopy analysis show that with increasing flow rate of C2H2, the structure of nanocomposite coatings changes from TiC nanograin-containing to graphite nanograin-containing DLC. The harness measurements show that the hardness decreases from 28 GPa to 18 GPa with increasing C2H2 flow rate. The scratch test show that a high critical load （〉40 N） was obtained and exhibited a good adhesion between the coating and the substrate. Wear experiment shows that the friction coefficient of TiC-DLC nanocomposite coatings decreases with increasing C2H2. A low friction coefficient of 0.07 was obtained at 480 sccm C2H2.
基金The project supported by the National Natural Science Foundation of China (No. 19835030 and 19875053)
文摘Diamond-like carbon (DLC) films are deposited on quartz substrate using pure CH4 in the surface wave plasma equipment. A direct current negative bias up to -90 V is applied to the substrate to investigate the bias effect on the film characteristics. Deposited films are characterized by Raman spectroscopy, infrared (IR) and ultraviolet-visible absorption techniques. There are two broad Raman peaks around 1340 cm-1 and 1600 cm-1 and the first one has a greater sp3 component with an increased bias. Infrared spectroscopy has three sp3 C-H modes at 2852 cm-1, 2926 cm-1 and 2962 cm-1, respectively and also shows an intensity increase with the negative bias. Optical band gap is calculated from the ultraviolet-visible absorption spectroscopy and the increased values with negative bias and deposition time are obtained. After a thermal anneal at about 500℃ for an hour to the film deposited under the bias of-90 V, we get an almost unchanged Raman spectrum and a peak intensity-reduced IR signal, which indicates a reduced H-content in the film. Meanwhile the optical band gap changed from 0.85 eV to 1.5 eV.
文摘目的研究硅(Si)、氧(O)元素掺杂对类金刚石(Diamond like Carbon,DLC)薄膜沉积、结构、表面形貌以及阻隔性能的影响,为高效制备高阻隔硅氧共掺类金刚石(Si and O Incorporated DLC,Si/O-DLC)薄膜提供新的思路参考。方法利用微波等离子体化学气相沉积(Plasma Enhanced Chemical Vapor Deposition,PECVD)技术在聚对苯二甲酸乙二醇酯(Polyethylene terephthalate,PET)基底表面沉积Si/O-DLC薄膜,具体研究反应单体中六甲基二硅氧烷(Hexaethyldisiloxane,HMDSO)含量对薄膜沉积和阻隔性能的影响。通过台阶仪、傅里叶红外光谱(FTIR)、X射线光电子能谱(XPS)、原子力显微镜(AFM)表征薄膜厚度、结构和微观形貌,并通过测试氧气透过率表征复合薄膜的阻隔性能。结果随着混合气体中HMDSO含量增加,薄膜的沉积速率提高,不同高度位置上沉积速率波动变弱,平均沉积速率最高达到310 nm·min^(–1),同时,薄膜中Si、O元素含量增加,相关的键合结构含量增加,薄膜表面致密性变差,氧气阻隔性能变弱;当HMDSO流量控制在1 mL·min^(–1)时,PET薄膜的氧气透过率可从未涂覆时的132mL·m^(2)·d^(–1)降低至2mL·m^(2)·d^(-1),阻隔性能明显改善。结论在一定工艺条件下,通过微波PECVD技术在PET薄膜表面涂覆Si/O-DLC薄膜,可明显改善其阻隔性能。
基金Funded by the National Natural Science Foundation of China(No.31570958)Science and Technology Support Program of Sichuan Province(No.2016SZ0007)
文摘The effects of surface adsorption of bovine serum albumin(BSA) and human gamma-globulin(HGG) on the tribological performance of a DLC film were investigated using a quartz crystal microbalance with dissipation(QCM-D), a ball-on-disk reciprocating tribometer, and a three-electrode electrochemical cell. The results showed that the wear depth in the BSA solution was higher than that in the HGG solution. In the HGG solution, the HGG-adsorbed layer could act as a lubricating layer and protect the DLC film from wear. The wear volume of DLC film in BSA and HGG mixture solution was higher than that in single HGG solution. This may be because the BSA molecules inhibit the formation of HGG adsorbed layer during sliding.
文摘The frictional resistance and machining quality when cutting carbon fiber reinforced plastics (CFRP) laminates are associated with tribological behavior of tool materials. In the present study, the tribological properties of three types of monolayer microcrystalline diamond (MCD) coatings, nanocrystalline diamond (NCD) coatings and dual-layer MCD/NCD coatings sliding against CFRP are investigated under dry lubricated conditions using the rotational friction tester. The coefficients of friction (COF), wear rate and worn surfaces of the contacted surfaces are analyzed for the MCD-CFRP, NCD-CFRP and MCD/NCD-CFRP contacting pairs. The results show that compared with the monolayer MCD and NCD, the bilayer of MCD/NCD coating displays the lowest COF with the value of ~0.13, it is 42% and 55% of the values for MCD and NCD coatings. Due to the rough surfaces of MCD, the wear debris of CFRP on MCD samples exhibits the plowing effect. While for the NCD and MCD/NCD samples, the wear fragments display the planar shapes. The wear rate of CFRP against MCD is more than twice that of CFRP against NCD, due to the excellent loading capacity. While the wear rate of CFRP against MCD/NCD is about twice than that of CFRP-NCD pairs. The bilayer of MCD/NCD combines the excellent advantages of high hardness of MCD and the smooth surface of NCD. It shows the broad application potential for the bilayer coatings.
文摘A unique diamond-like carbon (DLC) grinding wheel was developed, in which the DLC fibres were made by rolling Al sheets coated with DLC films and aligned no rmally to the grinding wheel surface by laminating Al sheets together with DLC fibres. In this paper, the formation process of DLC fibres and the fabrication process of a DLC fibre wheel were investigated. Many grinding experiments were also carried out on a precision NC plane milling machine using a newly developed DLC wheel. Grinding of specimens of silicon wafers, optical glasses, quartz, granites and hardened die steel SKD11 demonstrated the capabilities of nanometer surface finish. A smooth surface with a roughness value of Ra2.5 nm (Ry26 nm) was achieved.
文摘Fe ions in the fluence range of 2×1015 to 1×1017 cm-2 were implanted into diamond-like carbon (DLC) thin film of 100 nm thick, which were deposited on silicon substrate by plasma enhanced chemical vapor deposition. Effects of Fe ion implantation on microstructure and friction coefficient of the DLC were studied. With increasing Fe ion fluence, friction coefficient of the DLC film increased as compared with that of DLC without implantation, and then decreased. The Raman spectra characteristics also show a dependence on the Fe ion fluence. With increasing the ion fluence, the sp2 bonding increased in the DLC film, resulting in the decrease of friction coefficient of the film af- ter implantation. Substantial surface roughness was also measured.
基金supported by Grant-in aid of Japanese Ministry of Education,Culture,Sports,Science and Technology
文摘The friction, wear and lubrication of carbon nitride coatings on silicon substrates are studied using a spherical diamond counter-face with nano-scale asperities. The first part of this paper clarifies the coating thickness effect on factional behavior of carbon nitride coatings. The second part of this paper reports empirical data on wear properties in repeated sliding contacts through in situ examination and post-sliding observation. The third part will concentrate on wear mechanisms for the transition from "No observable wear particles" to "Wear particle generation." In light of the above tribological study, the application of carbon nitride coatings to MicroElectroMechanical system (MEMS) is therefore discussed from view points of both microtribology and micromachining.
基金support provided by the National Natural Science Foundation of China(Nos.51875172 and 52105180)Zhongyuan Science and Technology Innovation Leadership Program(No.214200510024).
文摘Organic molybdenum lubricant additive like molybdenum dialkyl dithiocarbamate(MoDTC)can cause wear acceleration of diamond-like carbon(DLC)coating coupled with steel under boundary lubrication,which hinders its industrial application.Therefore,polyisobutylene succinimide(PIBS),an organo molybdenum amide,was adopted to modify molybdenum oxide affording molybdenum polyisobutylene succinimidemolybdenum oxide nanoparticles(MPIBS-MONPs)with potential to prevent the wear acceleration of DLC coating.The thermal stability of MPIBS-MONPs was evaluated by thermogravimetric analysis.Their tribological properties as the additives in di-isooctyl sebacate(DIOS)were evaluated with MoDTC as a control;and their tribomechanism was investigated in relation to their tribochemical reactions and synergistic tribological effect with zinc dialkyldithiophosphate(ZDDP)as well as worn surface characterizations.Findings indicate that MPIBS-MONPs/ZDDP added in DIOS can significantly reduce the friction and wear of DLC coating,being much superior to MoDTC.This is because MPIBS-MONPs and ZDDP jointly take part in tribochemical reactions to form a composite tribofilm that can increase the wear resistance of DLC coating.Namely,the molybdenum amide on MPIBS-MONPs surface can react with ZDDP to form MoS2 film with excellent friction-reducing ability;and MPIBS-MONPs can release molybdenum oxide nanoparticle to form deposited lubrication layer on worn surfaces.The as-formed composite tribofilm consisting of molybdenum oxide nanocrystal,amorphous polyphosphate,and molybdenum disulfide as well as a small amount of Mo2C accounts for the increase in the wear resistance of DLC coating under boundary lubrication.
