In this article, the authors report on the use of Radio Frequency (RF) Magnetron Sputtering combined with Plasma-Based Ion Implantation (PBII) technique to synthesize the Boron-Carbon (B-C) films. High purity of boron...In this article, the authors report on the use of Radio Frequency (RF) Magnetron Sputtering combined with Plasma-Based Ion Implantation (PBII) technique to synthesize the Boron-Carbon (B-C) films. High purity of boron carbide (99.5%) disk was used as a target with an RF power of 300 W. The mixtures of Argon (Ar)-Methane (CH4) ware used as reactive gas under varying CH4 partial flow pressure at the specified range of 0 - 0.15 Pa and fixed total gas pressure and total gas flow at 0.30 Pa and 30 sccm, respectively. The effect of CH4 flow ratio on the friction coefficient of B-C films was studied. The friction coefficient of the film depended on the concentration of B. When it was 10% or lower, the coefficient decreased to 0.2 or lower. In this concentration range of B, the specific wear rate also decreased to the order of 10-7 mm3/Nm, and excellent wear resistance was displayed.展开更多
Diamond-like carbon (DLC) is a metastable amorphous material that exhibits unique properties. However, there are many limitations regarding the use of this material due to factors such as its tribological characterist...Diamond-like carbon (DLC) is a metastable amorphous material that exhibits unique properties. However, there are many limitations regarding the use of this material due to factors such as its tribological characteristics at high temperature and limited thermal stability. In this study, the thermal stability and tribological properties of DLC/silicon-nitrogen (DLC/Si-N) composite films were investigated and compared to those of pure DLC films. All the films were synthesized using a combination of radio frequency (RF) magnetron sputtering and plasma-based ion implantation (PBII) (a so-called sputtering-PBII hybrid system) which is newly developed by us. A high purity silicon nitride (99.9%) disk was used as the target, applying an RF power in the range of 500 - 700 W and a negative pulsed bias voltage of 5 kV to the substrate. An Ar-CH4 mixture was used as the reactive gas. The CH4 partial pressure was varied between 0 and 0.15 Pa, while the total gas pressure and total gas flow were fixed at 0.30 Pa and 30 sccm, respectively. The structures of the resulting films were characterized using Raman spectroscopy, while the thermal stabilities were assessed using thermogravimetric-differential thermal analysis (TG-DTA) and friction coefficients were obtained via ball-on-disk friction tests. The results indicate that the DLC/Si-N composite films produced in this work exhibit improved thermal stability relative to that of pure DLC owing to the presence of thermally stable atomic-scale Si-N compound in the carbon main flame networks. A DLC/Si-N film containing approximately 11 at.%Si and 18.5 at.%N shows good thermal stability in air over 800°C up to 1100°C, together with excellent tribological performance at 500°C in air. Overall, the data demonstrate that DLC/Si-N composite films offer improved thermal stability and superior tribological performance at high temperatures.展开更多
The composition and structure of PIII(plasma immersion ion implantation)carbonitrided Cr4Mo4V steel were analyzed using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),optical microscopy(OM)and SEM.The re...The composition and structure of PIII(plasma immersion ion implantation)carbonitrided Cr4Mo4V steel were analyzed using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),optical microscopy(OM)and SEM.The results indicate that the nitride and carbide are dispersion phase precipitation and except formation of compound other implantation atoms dissolve into martensite matrix.The total concentration of carbon and nitrogen is about 30 at%near the surface,and still keeps at about 20 at%even at the depth of 8μm.The effect of treatment temperature,implantation time and ratio of N2 to CH4 on the hardness and wear resistance of carbonitrided layer are investigated.It is found that the hardness of Cr4Mo4V steel increases after treatment.The highest hardness of samples is 22.3 GPa,which is about 1.8 times than initial steel.The dry-wear resistance of the samples is also improved after treatment,and the sample with higher hardness shows the better wear resistance.展开更多
Poly[（μ4-2,6-dimethylpyridine-3,5-dicarboxylato）dihydrate]diaqualead（II）] （1） exhi- bits a two-dimensional （2-D） layer structure in which the asymmetric unit contains one Pbn centre, one 2,6-dimethylpyridine-...Poly[（μ4-2,6-dimethylpyridine-3,5-dicarboxylato）dihydrate]diaqualead（II）] （1） exhi- bits a two-dimensional （2-D） layer structure in which the asymmetric unit contains one Pbn centre, one 2,6-dimethylpyridine-3,5-dicarboxylate （mpdc） ligand and two coordinated water molecules. Each Pbn ion is eight-coordinated and surrounded by eight O atoms from five different mpdc ligands and two terminal water molecules to furnish a distorted square antiprism coordination geometry. The infinite connection of the one-dimensional （1-D） [PbO4（H2O）2]n chains bridged by ligands forms the 2-D [Pb（mpdc）]n layer Structure. In 1, the layers further build up a three- dimensional （3-D） supramolecular architecture via interlaminar hydrogen bonds and π-π stacking.展开更多
The bondstructureofhydrogenated diamond likecarbon( DLC) filmsdeposited with plasmabased ionimplantation ( PBII) wascharacterized by Raman spectroscopy andcore level band and valenceband spectrum of XPS. Theresults...The bondstructureofhydrogenated diamond likecarbon( DLC) filmsdeposited with plasmabased ionimplantation ( PBII) wascharacterized by Raman spectroscopy andcore level band and valenceband spectrum of XPS. Theresultsshow thatthe hydrogenated carbon filmspre pared with lower pulse bias, especially zero bias, display polymer like feature. The DLCfilms deposited with 15 kVpulsebiascontainsthehighestdensityofsp3 bonds. Thecore lev elband ( C1s) spectra of allfilmsshifttowardlow bindingenergy after4kVAr+ ion bom barding. The valenceband spectra of hydrogenated DLCfilmsarequite differentfrom thatof diamond and graphite. However, afterion bombarding, besidetwosingle peaksatabout17 0 eVand 12 5 eV(similarto graphite) ,two new sharp peaksappearatabout21 3 eVand 8 0 eV,respectively. Thepeak at8 0 eVcan beconsidertothecontribution duetothe actingofimplanted argon on C Cbondsand C Hbondsin thefilms.展开更多
aluminum alloy was implanted with nitrogen then titanium finally carbon by plasma-based ion implantatio to form a gradient layer. The structure and tribological properties of the layer were investigated. Its compositi...aluminum alloy was implanted with nitrogen then titanium finally carbon by plasma-based ion implantatio to form a gradient layer. The structure and tribological properties of the layer were investigated. Its composition profiles and chemical states were analyzed with X-ray photoelectron spectroscopy(XPS). The surface carbon layer was analyzed by Raman spectrum. The appearances were observed by atomic force microscope (AFM). The surface hardness was measured with the mechanical property microprobe. The dry wear tests against GCr15 steel ball at various sliding loads were performed with a ball-on-disk wear tester in ambient environment. The results show that the thickness of the modified layer is 1 200 nm, the carbon layer is a smooth and compact diamond-like carbon(DLC) films, and the carbon-titanium interface is broadened due to carbon ions implantation, resulting in a good composition and structure transition between DLC films and titanium layer. Surface hardness is improved markedly, with a slow and uniform change. Tribological properties are improved greatly although they reduce with the increase of sliding loads because the modified layer becomes thin rapidly.展开更多
文摘In this article, the authors report on the use of Radio Frequency (RF) Magnetron Sputtering combined with Plasma-Based Ion Implantation (PBII) technique to synthesize the Boron-Carbon (B-C) films. High purity of boron carbide (99.5%) disk was used as a target with an RF power of 300 W. The mixtures of Argon (Ar)-Methane (CH4) ware used as reactive gas under varying CH4 partial flow pressure at the specified range of 0 - 0.15 Pa and fixed total gas pressure and total gas flow at 0.30 Pa and 30 sccm, respectively. The effect of CH4 flow ratio on the friction coefficient of B-C films was studied. The friction coefficient of the film depended on the concentration of B. When it was 10% or lower, the coefficient decreased to 0.2 or lower. In this concentration range of B, the specific wear rate also decreased to the order of 10-7 mm3/Nm, and excellent wear resistance was displayed.
文摘Diamond-like carbon (DLC) is a metastable amorphous material that exhibits unique properties. However, there are many limitations regarding the use of this material due to factors such as its tribological characteristics at high temperature and limited thermal stability. In this study, the thermal stability and tribological properties of DLC/silicon-nitrogen (DLC/Si-N) composite films were investigated and compared to those of pure DLC films. All the films were synthesized using a combination of radio frequency (RF) magnetron sputtering and plasma-based ion implantation (PBII) (a so-called sputtering-PBII hybrid system) which is newly developed by us. A high purity silicon nitride (99.9%) disk was used as the target, applying an RF power in the range of 500 - 700 W and a negative pulsed bias voltage of 5 kV to the substrate. An Ar-CH4 mixture was used as the reactive gas. The CH4 partial pressure was varied between 0 and 0.15 Pa, while the total gas pressure and total gas flow were fixed at 0.30 Pa and 30 sccm, respectively. The structures of the resulting films were characterized using Raman spectroscopy, while the thermal stabilities were assessed using thermogravimetric-differential thermal analysis (TG-DTA) and friction coefficients were obtained via ball-on-disk friction tests. The results indicate that the DLC/Si-N composite films produced in this work exhibit improved thermal stability relative to that of pure DLC owing to the presence of thermally stable atomic-scale Si-N compound in the carbon main flame networks. A DLC/Si-N film containing approximately 11 at.%Si and 18.5 at.%N shows good thermal stability in air over 800°C up to 1100°C, together with excellent tribological performance at 500°C in air. Overall, the data demonstrate that DLC/Si-N composite films offer improved thermal stability and superior tribological performance at high temperatures.
基金supported by NSFC(51001039)National Basic Research Program of China(No.2007CB607602)+1 种基金The Program of Excellent Teams of Harbin Institute of TechnologyScience Found for Distinguished Yong Schoolars of Heilongjiang Province(JC200901)
文摘The composition and structure of PIII(plasma immersion ion implantation)carbonitrided Cr4Mo4V steel were analyzed using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),optical microscopy(OM)and SEM.The results indicate that the nitride and carbide are dispersion phase precipitation and except formation of compound other implantation atoms dissolve into martensite matrix.The total concentration of carbon and nitrogen is about 30 at%near the surface,and still keeps at about 20 at%even at the depth of 8μm.The effect of treatment temperature,implantation time and ratio of N2 to CH4 on the hardness and wear resistance of carbonitrided layer are investigated.It is found that the hardness of Cr4Mo4V steel increases after treatment.The highest hardness of samples is 22.3 GPa,which is about 1.8 times than initial steel.The dry-wear resistance of the samples is also improved after treatment,and the sample with higher hardness shows the better wear resistance.
基金Supported by the Science and Technology Projects of Chongqing Municipal Education Commission(KJ060805,KJ100602)Chongqing Normal University Scientific Research Foundation Project(10XLZ005,2011XLS30)
文摘Poly[（μ4-2,6-dimethylpyridine-3,5-dicarboxylato）dihydrate]diaqualead（II）] （1） exhi- bits a two-dimensional （2-D） layer structure in which the asymmetric unit contains one Pbn centre, one 2,6-dimethylpyridine-3,5-dicarboxylate （mpdc） ligand and two coordinated water molecules. Each Pbn ion is eight-coordinated and surrounded by eight O atoms from five different mpdc ligands and two terminal water molecules to furnish a distorted square antiprism coordination geometry. The infinite connection of the one-dimensional （1-D） [PbO4（H2O）2]n chains bridged by ligands forms the 2-D [Pb（mpdc）]n layer Structure. In 1, the layers further build up a three- dimensional （3-D） supramolecular architecture via interlaminar hydrogen bonds and π-π stacking.
文摘The bondstructureofhydrogenated diamond likecarbon( DLC) filmsdeposited with plasmabased ionimplantation ( PBII) wascharacterized by Raman spectroscopy andcore level band and valenceband spectrum of XPS. Theresultsshow thatthe hydrogenated carbon filmspre pared with lower pulse bias, especially zero bias, display polymer like feature. The DLCfilms deposited with 15 kVpulsebiascontainsthehighestdensityofsp3 bonds. Thecore lev elband ( C1s) spectra of allfilmsshifttowardlow bindingenergy after4kVAr+ ion bom barding. The valenceband spectra of hydrogenated DLCfilmsarequite differentfrom thatof diamond and graphite. However, afterion bombarding, besidetwosingle peaksatabout17 0 eVand 12 5 eV(similarto graphite) ,two new sharp peaksappearatabout21 3 eVand 8 0 eV,respectively. Thepeak at8 0 eVcan beconsidertothecontribution duetothe actingofimplanted argon on C Cbondsand C Hbondsin thefilms.
文摘aluminum alloy was implanted with nitrogen then titanium finally carbon by plasma-based ion implantatio to form a gradient layer. The structure and tribological properties of the layer were investigated. Its composition profiles and chemical states were analyzed with X-ray photoelectron spectroscopy(XPS). The surface carbon layer was analyzed by Raman spectrum. The appearances were observed by atomic force microscope (AFM). The surface hardness was measured with the mechanical property microprobe. The dry wear tests against GCr15 steel ball at various sliding loads were performed with a ball-on-disk wear tester in ambient environment. The results show that the thickness of the modified layer is 1 200 nm, the carbon layer is a smooth and compact diamond-like carbon(DLC) films, and the carbon-titanium interface is broadened due to carbon ions implantation, resulting in a good composition and structure transition between DLC films and titanium layer. Surface hardness is improved markedly, with a slow and uniform change. Tribological properties are improved greatly although they reduce with the increase of sliding loads because the modified layer becomes thin rapidly.
