This paper presents the surface temperature behavior of M42 high-speed tool steel samples during N+ implantation in an industrialized GLZ-100 metal-ion implantation machine. A detail study has been made on the paramet...This paper presents the surface temperature behavior of M42 high-speed tool steel samples during N+ implantation in an industrialized GLZ-100 metal-ion implantation machine. A detail study has been made on the parameters of N+ implantation. Optimized technical parameters have been presented. The microhardness of the sample surface implanted under these parameters has been increased by a factor of 2.3, and the wear-resistance has been improved by about 5.4 times. The research on the mechanism of surface modification of M42 steel by nitrogen ion implantation has also been made.展开更多
Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples ex...Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).展开更多
The nanosecond(ns) pulsed nitrogen dielectric barrier discharge(DBD) is employed to enhance the hydrophilicity of polypropylene(PP) surface and improve its application effect.The discharge characteristics of the ns pu...The nanosecond(ns) pulsed nitrogen dielectric barrier discharge(DBD) is employed to enhance the hydrophilicity of polypropylene(PP) surface and improve its application effect.The discharge characteristics of the ns pulsed nitrogen DBD with different pulse rise times(from 50to 500 ns) are investigated by electrical and optical diagnostic methods and the discharge uniformity is quantitatively analyzed by image processing method.To characterize the surface hydrophilicity,the water contact angle(WCA) is measured,and the physical morphology and chemical composition of PP before and after modification are analyzed to explore the effect of plasma on PP surface.It is found that with increasing pulse rise time from 50 to 500 ns,DBD uniformity becomes worse,energy efficiency decreases from 20% to 10.8%,and electron density decrease from 6.6 × 10^(11)to 5.5 × 10^(11)cm^(-3).The tendency of electron temperature is characterized with the intensity ratio of N_(2)/N_(2)^(+)emission spectrum,which decreases from 17.4 to15.9 indicating the decreasing of T_(e) with increasing pulse rise time from 50 to 500 ns.The PP surface treated with 50 ns pulse rise time DBD has a lower WCA(~47°),while the WCA of PP treated with 100 to 500 ns pulse rise time DBD expands gradually(~50°–57°).According to the study of the fixed-point WCA values,the DBD-treated PP surface has superior uniformity under50 ns pulse rise time(3° variation) than under 300 ns pulse rise time(8° variation).After DBD treatment,the increased surface roughness from 2.0 to 9.8 nm and hydrophilic oxygencontaining groups on the surface,i.e.hydroxyl(-OH) and carbonyl(C=O) have played the significant role to improve the sample’s surface hydrophilicity.The short pulse voltage rise time enhances the reduced electric field strength(E/n) in the discharge space and improves the discharge uniformity,which makes relatively sufficient physical and chemical reactions have taken place on the PP surface,resulting in better treatment uniformity.展开更多
The surface modification of nanometer carbon material has been studied by using an Induced Dielectric Barrier Discharge Plasma device (IDBD). The experimental results show that with different work gases and different ...The surface modification of nanometer carbon material has been studied by using an Induced Dielectric Barrier Discharge Plasma device (IDBD). The experimental results show that with different work gases and different discharge conditions, the surface behaviors of carbon black can be changed according to needs, including the use of different functional groups and the change of the surface roughness of carbon particles etc., which increased the grinding and dispersion abilities in binder.展开更多
文摘This paper presents the surface temperature behavior of M42 high-speed tool steel samples during N+ implantation in an industrialized GLZ-100 metal-ion implantation machine. A detail study has been made on the parameters of N+ implantation. Optimized technical parameters have been presented. The microhardness of the sample surface implanted under these parameters has been increased by a factor of 2.3, and the wear-resistance has been improved by about 5.4 times. The research on the mechanism of surface modification of M42 steel by nitrogen ion implantation has also been made.
文摘Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).
基金supported by National Natural Science Foundation of China (Nos. 52037004, 51777091 and52250410350)Postgraduate Research&Practice Innovation Program of Jiangsu Province (No.KYCX22_1314)。
文摘The nanosecond(ns) pulsed nitrogen dielectric barrier discharge(DBD) is employed to enhance the hydrophilicity of polypropylene(PP) surface and improve its application effect.The discharge characteristics of the ns pulsed nitrogen DBD with different pulse rise times(from 50to 500 ns) are investigated by electrical and optical diagnostic methods and the discharge uniformity is quantitatively analyzed by image processing method.To characterize the surface hydrophilicity,the water contact angle(WCA) is measured,and the physical morphology and chemical composition of PP before and after modification are analyzed to explore the effect of plasma on PP surface.It is found that with increasing pulse rise time from 50 to 500 ns,DBD uniformity becomes worse,energy efficiency decreases from 20% to 10.8%,and electron density decrease from 6.6 × 10^(11)to 5.5 × 10^(11)cm^(-3).The tendency of electron temperature is characterized with the intensity ratio of N_(2)/N_(2)^(+)emission spectrum,which decreases from 17.4 to15.9 indicating the decreasing of T_(e) with increasing pulse rise time from 50 to 500 ns.The PP surface treated with 50 ns pulse rise time DBD has a lower WCA(~47°),while the WCA of PP treated with 100 to 500 ns pulse rise time DBD expands gradually(~50°–57°).According to the study of the fixed-point WCA values,the DBD-treated PP surface has superior uniformity under50 ns pulse rise time(3° variation) than under 300 ns pulse rise time(8° variation).After DBD treatment,the increased surface roughness from 2.0 to 9.8 nm and hydrophilic oxygencontaining groups on the surface,i.e.hydroxyl(-OH) and carbonyl(C=O) have played the significant role to improve the sample’s surface hydrophilicity.The short pulse voltage rise time enhances the reduced electric field strength(E/n) in the discharge space and improves the discharge uniformity,which makes relatively sufficient physical and chemical reactions have taken place on the PP surface,resulting in better treatment uniformity.
文摘The surface modification of nanometer carbon material has been studied by using an Induced Dielectric Barrier Discharge Plasma device (IDBD). The experimental results show that with different work gases and different discharge conditions, the surface behaviors of carbon black can be changed according to needs, including the use of different functional groups and the change of the surface roughness of carbon particles etc., which increased the grinding and dispersion abilities in binder.
