The tribological behaviors of the nano-diamond particles including the nano- diamond and the nano-diamond modified were studied at high temperature using SRV multifunctional test system. The worn steel surfaces were a...The tribological behaviors of the nano-diamond particles including the nano- diamond and the nano-diamond modified were studied at high temperature using SRV multifunctional test system. The worn steel surfaces were analyzed by means of X-ray photoelectron spectroscopy (XPS). The results show that nano-diamond particles can obviously improve the antiwear and friction reducing properties of the base oil at high temperature and the high load. The friction coefficient of the nano-diamond is very low at 200 ℃ when the test load is not more than 20 N. This tribological behaviors should attributed to the similarly to “ball bearing” lubrication action of the nano-diamond particles, so the movement between tribological pairs become sliding/rolling. The nano-diamond modified by dimer ester possesses excellent antiwear and friction reducing performance at 500 ℃ and load 500 N. The tribochemical reaction film between the nano-diamond particles and the renascent wear surface plays dominating lubrication role and the presence of the dimer ester on the rubbing surface can be propitious to form lubrication film containing nano- diamond on the worn surface at high temperature and high load.展开更多
The mixture of Nano-graphite and organic vehicles doped to Nano-diamond paste. The suitable paste proportion was found. Nano-diamond film (NDF) was prepared by sol-gel coating method on ITO glass at 3000/min. The fiel...The mixture of Nano-graphite and organic vehicles doped to Nano-diamond paste. The suitable paste proportion was found. Nano-diamond film (NDF) was prepared by sol-gel coating method on ITO glass at 3000/min. The field emission characteristics of luminance-current, luminance-voltage and luminance-power of Nano-diamond film were analyzed and tested. Comparing these tested curves, the luminance was well proportional to current was got. Theoretic, the inner resistance of NDF field emission display (FED) consumes electric energy and real voltage change between the cathode and the anode of NDF-FED was very small after electrons emit. So the characteristic of NDF-FED was preferable to describe by luminance-current linear relationship, which was advantageous to device tested and designed.展开更多
The properties of hydrogen atoms in a nano-diamond grain surrounded by an amorphous carbon shell are studied with Tight Binding computer simulations.Our samples model nano-diamond grains,of a few nanometers in size,th...The properties of hydrogen atoms in a nano-diamond grain surrounded by an amorphous carbon shell are studied with Tight Binding computer simulations.Our samples model nano-diamond grains,of a few nanometers in size,that nucleate within an amorphous carbon matrix,as observed in deposition from a hydrocarbon rich plasma.The calculations show that the average hydrogen interstitial formation energy in the amorphous region is lower than in the nano-diamond core,therefore hydrogen interstitial sites in the in the amorphous region are more stable than in the nano-diamond core.This formation energy difference is the driving force for the diffusion of hydrogen atoms from nano-diamond grains into amorphous carbon regions.An energy well was observed on the amorphous side of the nano-diamond amorphous carbon interface:hydrogen atoms are expected to be trapped here.This scenario agrees with experimental results which show that hydrogen retention of diamond films increases with decreasing grain size,and suggest that hydrogen is bonded and trapped in nano-diamond grain boundaries and on internal grain surfaces.展开更多
文摘The tribological behaviors of the nano-diamond particles including the nano- diamond and the nano-diamond modified were studied at high temperature using SRV multifunctional test system. The worn steel surfaces were analyzed by means of X-ray photoelectron spectroscopy (XPS). The results show that nano-diamond particles can obviously improve the antiwear and friction reducing properties of the base oil at high temperature and the high load. The friction coefficient of the nano-diamond is very low at 200 ℃ when the test load is not more than 20 N. This tribological behaviors should attributed to the similarly to “ball bearing” lubrication action of the nano-diamond particles, so the movement between tribological pairs become sliding/rolling. The nano-diamond modified by dimer ester possesses excellent antiwear and friction reducing performance at 500 ℃ and load 500 N. The tribochemical reaction film between the nano-diamond particles and the renascent wear surface plays dominating lubrication role and the presence of the dimer ester on the rubbing surface can be propitious to form lubrication film containing nano- diamond on the worn surface at high temperature and high load.
文摘The mixture of Nano-graphite and organic vehicles doped to Nano-diamond paste. The suitable paste proportion was found. Nano-diamond film (NDF) was prepared by sol-gel coating method on ITO glass at 3000/min. The field emission characteristics of luminance-current, luminance-voltage and luminance-power of Nano-diamond film were analyzed and tested. Comparing these tested curves, the luminance was well proportional to current was got. Theoretic, the inner resistance of NDF field emission display (FED) consumes electric energy and real voltage change between the cathode and the anode of NDF-FED was very small after electrons emit. So the characteristic of NDF-FED was preferable to describe by luminance-current linear relationship, which was advantageous to device tested and designed.
文摘The properties of hydrogen atoms in a nano-diamond grain surrounded by an amorphous carbon shell are studied with Tight Binding computer simulations.Our samples model nano-diamond grains,of a few nanometers in size,that nucleate within an amorphous carbon matrix,as observed in deposition from a hydrocarbon rich plasma.The calculations show that the average hydrogen interstitial formation energy in the amorphous region is lower than in the nano-diamond core,therefore hydrogen interstitial sites in the in the amorphous region are more stable than in the nano-diamond core.This formation energy difference is the driving force for the diffusion of hydrogen atoms from nano-diamond grains into amorphous carbon regions.An energy well was observed on the amorphous side of the nano-diamond amorphous carbon interface:hydrogen atoms are expected to be trapped here.This scenario agrees with experimental results which show that hydrogen retention of diamond films increases with decreasing grain size,and suggest that hydrogen is bonded and trapped in nano-diamond grain boundaries and on internal grain surfaces.
