TiN coatings were deposited on polished substrates of W18Cr4V high speed steel by means of vacuum arc ion plating. The effect of cerium on adhesion between TiN coating and substrate was studied. The microstructures an...TiN coatings were deposited on polished substrates of W18Cr4V high speed steel by means of vacuum arc ion plating. The effect of cerium on adhesion between TiN coating and substrate was studied. The microstructures and composition of TiN coatings were also investigated by means of scanning electron microscope (SEM), Auger electron spectroscopy (AES), and X ray diffraction (XRD) technique. It was found that cerium is an effective modifying agent and the addition of suitable amount of cerium to TiN coatings can produce relatively excellent properties such as micro hardness, wear resistance, oxidation resistance and porosity. The experimental results show that the added cerium in TiN coatings makes a contribution to form the preferred direction along with a (111) or (222) close packed face, which may be one of the reasons that improves some properties mentioned above.展开更多
Sn thin film on Cu foil substrate as the anode of lithium ion battery was prepared by direct current magnetron sputtering(DCMS). The surface morphology,composition and thickness and the electrochemical behaviors of th...Sn thin film on Cu foil substrate as the anode of lithium ion battery was prepared by direct current magnetron sputtering(DCMS). The surface morphology,composition and thickness and the electrochemical behaviors of the prepared Sn thin film were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),inductively coupled plasma atomic emission spectrometry(ICP),cyclic voltammetry(CV) and galvanostatic charge/ discharge(GC) measurements. It is found that the Sn film is consists of pure Sn with an average particle diameter of 100 nm. The thickness of the film is about 320 nm. The initial lithium insertion capacity of the Sn film is 771 mA·h/g. The reversible capacity of the film is 570 mA·h/g and kept at 270 mA·h/g after 20 cycles.展开更多
Cu46Zr47-xAl7Mx(M = Ce,Pr,Tb,and Gd) bulk metallic glassy(BMG) alloys were prepared by copper-mold vacuum suction casting.The effects of rare-earth elements on the glass-forming ability(GFA),thermal stability,and mech...Cu46Zr47-xAl7Mx(M = Ce,Pr,Tb,and Gd) bulk metallic glassy(BMG) alloys were prepared by copper-mold vacuum suction casting.The effects of rare-earth elements on the glass-forming ability(GFA),thermal stability,and mechanical properties of Cu46Zr47-xAl7Mx were investigated.The GFA of Cu46Zr47-xAl7Mx(M = Ce,Pr) alloys is dependent on the content of Ce and Pr,and the optimal content is 4.at %.Cu46Zr47-xAl7Tbx(x = 2,4,and 5) amorphous alloys with a diameter of 5 mm can be prepared.The GFA of Cu46Zr47-xAl7Gdx(x = 2,4,and 5) increases with increasing Gd.Tx and Tp of all decrease.Tg is dependent on the rare-earth element and its content.△Tx for most of these alloys decreases except the Cu46Zr42Al7Gd5 alloy.The activation energies △Eg,△Ex,and △Ep for the Cu46Zr42Al7Gd5 BMG alloy with Kissinger equations are 340.7,211.3,and 211.3 kJ/mol,respectively.These values with Ozawa equations are 334.8,210.3,and 210.3 kJ/mol,respectively.The Cu46Zr45Al7Tb2 alloy presents the highest microhardness,Hv 590,while the Cu46Zr43Al7Pr4 alloy presents the least,Hv 479.The compressive strength(σc.f.) of the Cu46Zr43Al7Gd4 BMG alloy is higher than that of the Cu46Zr43Al7Tb4 BMG alloy.展开更多
The bulk metallic glassy(BMG) rods of [(Fe0.5Co0.5)0.72B0.192Si0.048Nb0.04]100-xYx(x=0-6) and [(FexCo1-x)0.72B0.192Si0.048Nb0.04]96Y4(x=0.5-0.8) were prepared by copper mold casting.The structure,thermal stability,and...The bulk metallic glassy(BMG) rods of [(Fe0.5Co0.5)0.72B0.192Si0.048Nb0.04]100-xYx(x=0-6) and [(FexCo1-x)0.72B0.192Si0.048Nb0.04]96Y4(x=0.5-0.8) were prepared by copper mold casting.The structure,thermal stability,and magnetic properties of the samples were studied by X-ray diffraction(XRD),differential scanning calorimetry(DSC),and vibrating sample magnetometer(VSM).Adding 1at% to 6at% of yttrium,the bulk glassy alloy rods of [(Fe0.5Co0.5)0.72B0.192Si0.048Nb0.04]100-xYx(x=0-6) with the diameter of 3 mm were not formed,and the sample with 4at% of yttrium showed less crystalline phase than others.When the Fe/Co atomic ratio was between 5:5 and 7:3,the bulk glassy alloy rods of [(Fe1-xCox)0.72B0.192Si0.048Nb0.04]96Y4(x=0.5-0.8) with the diameter of 2 mm were fabricated.In the(Fe,Co)-B-Si-Nb-Y BMGs,when the Fe content increased,the thermal stability,the supercooled liquid region,and the glass-forming ability(GFA) decreased,but the saturation magnetization(Ms) increased.展开更多
A tin film of 320 nm in thickness on Cu foil and its composite film with graphite of ～50 nm in thickness on it were fabricated by magnetron sputtering. The surface morphology, composition, surface distributions of al...A tin film of 320 nm in thickness on Cu foil and its composite film with graphite of ～50 nm in thickness on it were fabricated by magnetron sputtering. The surface morphology, composition, surface distributions of alloy elements, and lithium intercalation/de-intercalation behaviors of the fabricated films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectrometry (ICP), cyclic voltammetry (CV), and galvanostatic charge/discharge (GC) measurements. It is found that the lithium intercalation/de-intercalation behavior of the Sn film can be significantly improved by its composite with graphite. With cycling, the discharge capacity of the Sn film without composite changes from 570 mAh/g of the 2nd cycle to 270 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 90% and 95%. Nevertheless, the discharge capacity of the composite Sn/C film changes from 575 mAh/g of the 2nd cycle to 515 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 95% and 100%. The performance improvement of tin by its composite with graphite is ascribed to the retardation of the bulk tin cracking from volume change during lithium intercalation and de-intercalation, which leads to the pulverization of tin.展开更多
Tribological characteristics of new series of Al Sn Si alloys were investigated by means of pin disk types of wear testing machines, OM, SEM and EDAX. Rules about the influence of Sn, Si content and load on the fricti...Tribological characteristics of new series of Al Sn Si alloys were investigated by means of pin disk types of wear testing machines, OM, SEM and EDAX. Rules about the influence of Sn, Si content and load on the friction and wear characteristics of the alloys were ascertained. The friction factor and wear rate of the alloys decrease with increasing Sn content, the wear rate decreases but the friction factor varies hardly with increasing Si content. The friction factor of the alloys increases slightly and the wear rate increases observably with increasing load in the range of 1080 N. The wear mechanism of Al Sn Si alloys consists of ‘plough’ action and abrasive wear below 30 N; the adhesive and delamination mechanism are shown in the range of 3080 N. The tribological characteristics of Al Sn Si system are superior to those of Al Sn or Al Si systems due to their “peritectic type” island shape microstructure of Si surrounded with Sn.展开更多
Tin carbon nanotube(Sn-CNTs) composite was prepared by ultrasonic-electrodepositing tin on the substrate of copper foil in a sulfate bath containing carbon nanotubes(CNTs). The composites were characterized by scannin...Tin carbon nanotube(Sn-CNTs) composite was prepared by ultrasonic-electrodepositing tin on the substrate of copper foil in a sulfate bath containing carbon nanotubes(CNTs). The composites were characterized by scanning electron microscopy(SEM),cyclic voltammetry(CV) and charge-discharge cycling test. The results show that Sn-CNTs have a better electrochemical performance than Sn. The capacity of Sn-CNTs is 843 mA·h/g during the first discharge and the efficiency of charge-discharge reaches 85%. After 50 cycles,the capacity of Sn-CNTs keeps at 380 mA·h/g. The CNTs in tin act as a structure supporter and play a role of an elastomer and conductive network,alleviating the electrode dilapidation resulted from volume change during the lithium insertion and deinsertion.展开更多
Nano-carbon and iron composite―carbon-coated iron nanoparticles (CCINs) produced by carbon arc method can be used as a new kind of magnetic targeting induction heating drug carrier for cancer therapy. The structure a...Nano-carbon and iron composite―carbon-coated iron nanoparticles (CCINs) produced by carbon arc method can be used as a new kind of magnetic targeting induction heating drug carrier for cancer therapy. The structure and morphology of CCINs are studied by X-ray diffraction (XRD) and transmission electron microscope (TEM). Mossbauer spectra of these nanoparticles show that they contain only iron and carbon, without ferric carbide and ferric oxide. CCINs can be used as the magnetic drug carrier, with the effect of targeting magnetic induction heating in its inner core and higher drug adsorption in its nano-carbon shell outside because of its high specific surface area. CCINs can absorb Epirubicin (EPI) of 160 μg/mg measured by an optical spectrometer. In acute toxicity experiment with mice, the median lethal dose (LD50) of EPI is 16.9 mg/kg, while that of EPI-CCINs mixture is 20.7 mg/kg and none of the mice died after pure CCINs medication. The results show that pure CCINs belong to non-toxic grade and EPI delivery in mixture with CCINs can reduce its acute toxicity in mice. The magnetic properties of CCINs and their magnetic induction heating are investigated. The iron nanoparticle in its inner core has better magnetism with a good effect on targeting magnetic induction heating. When the CCINs are mixed with physiological salt water and are injected uniformly in pig's liver, the temperature goes up to 48℃. While in the case that CCINs are filled in a certain section of pig's liver, the temperature goes up to 52℃. In both cases the temperature is high enough to kill the cancer cell. CCINs have potential applications in cancer therapy.展开更多
文摘TiN coatings were deposited on polished substrates of W18Cr4V high speed steel by means of vacuum arc ion plating. The effect of cerium on adhesion between TiN coating and substrate was studied. The microstructures and composition of TiN coatings were also investigated by means of scanning electron microscope (SEM), Auger electron spectroscopy (AES), and X ray diffraction (XRD) technique. It was found that cerium is an effective modifying agent and the addition of suitable amount of cerium to TiN coatings can produce relatively excellent properties such as micro hardness, wear resistance, oxidation resistance and porosity. The experimental results show that the added cerium in TiN coatings makes a contribution to form the preferred direction along with a (111) or (222) close packed face, which may be one of the reasons that improves some properties mentioned above.
基金Projects(50771046 20373016) supported by the National Natural Science Foundation of China+2 种基金Project(05200534) supported by the Natural Science Foundation of Guangdong Province, ChinaProject(2006A10704003) supported by the Key Project of Guangdong Province, ChinaProject(2006Z3-D2031) supported by the Key Project of Guangzhou City, China
文摘Sn thin film on Cu foil substrate as the anode of lithium ion battery was prepared by direct current magnetron sputtering(DCMS). The surface morphology,composition and thickness and the electrochemical behaviors of the prepared Sn thin film were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),inductively coupled plasma atomic emission spectrometry(ICP),cyclic voltammetry(CV) and galvanostatic charge/ discharge(GC) measurements. It is found that the Sn film is consists of pure Sn with an average particle diameter of 100 nm. The thickness of the film is about 320 nm. The initial lithium insertion capacity of the Sn film is 771 mA·h/g. The reversible capacity of the film is 570 mA·h/g and kept at 270 mA·h/g after 20 cycles.
文摘Cu46Zr47-xAl7Mx(M = Ce,Pr,Tb,and Gd) bulk metallic glassy(BMG) alloys were prepared by copper-mold vacuum suction casting.The effects of rare-earth elements on the glass-forming ability(GFA),thermal stability,and mechanical properties of Cu46Zr47-xAl7Mx were investigated.The GFA of Cu46Zr47-xAl7Mx(M = Ce,Pr) alloys is dependent on the content of Ce and Pr,and the optimal content is 4.at %.Cu46Zr47-xAl7Tbx(x = 2,4,and 5) amorphous alloys with a diameter of 5 mm can be prepared.The GFA of Cu46Zr47-xAl7Gdx(x = 2,4,and 5) increases with increasing Gd.Tx and Tp of all decrease.Tg is dependent on the rare-earth element and its content.△Tx for most of these alloys decreases except the Cu46Zr42Al7Gd5 alloy.The activation energies △Eg,△Ex,and △Ep for the Cu46Zr42Al7Gd5 BMG alloy with Kissinger equations are 340.7,211.3,and 211.3 kJ/mol,respectively.These values with Ozawa equations are 334.8,210.3,and 210.3 kJ/mol,respectively.The Cu46Zr45Al7Tb2 alloy presents the highest microhardness,Hv 590,while the Cu46Zr43Al7Pr4 alloy presents the least,Hv 479.The compressive strength(σc.f.) of the Cu46Zr43Al7Gd4 BMG alloy is higher than that of the Cu46Zr43Al7Tb4 BMG alloy.
基金supported by the National Natural Science Foundation of China (Nos50771037,50971046)the Doctoral Program Foundation of the Ministry of Education of China (No200805620004)the Natural Science Foundation of Guangdong Province,China (No06021473)
文摘The bulk metallic glassy(BMG) rods of [(Fe0.5Co0.5)0.72B0.192Si0.048Nb0.04]100-xYx(x=0-6) and [(FexCo1-x)0.72B0.192Si0.048Nb0.04]96Y4(x=0.5-0.8) were prepared by copper mold casting.The structure,thermal stability,and magnetic properties of the samples were studied by X-ray diffraction(XRD),differential scanning calorimetry(DSC),and vibrating sample magnetometer(VSM).Adding 1at% to 6at% of yttrium,the bulk glassy alloy rods of [(Fe0.5Co0.5)0.72B0.192Si0.048Nb0.04]100-xYx(x=0-6) with the diameter of 3 mm were not formed,and the sample with 4at% of yttrium showed less crystalline phase than others.When the Fe/Co atomic ratio was between 5:5 and 7:3,the bulk glassy alloy rods of [(Fe1-xCox)0.72B0.192Si0.048Nb0.04]96Y4(x=0.5-0.8) with the diameter of 2 mm were fabricated.In the(Fe,Co)-B-Si-Nb-Y BMGs,when the Fe content increased,the thermal stability,the supercooled liquid region,and the glass-forming ability(GFA) decreased,but the saturation magnetization(Ms) increased.
基金the National Nature Science Foundation of China (Nos. 50771046 and 20373016) the Natural Science Foundation of Guangdong Province (No. 05200534)the Key Projects of Guangdong Province and Guangzhou City, China (Nos. 2006A10704003 and 2006Z3-D2031)
文摘A tin film of 320 nm in thickness on Cu foil and its composite film with graphite of ～50 nm in thickness on it were fabricated by magnetron sputtering. The surface morphology, composition, surface distributions of alloy elements, and lithium intercalation/de-intercalation behaviors of the fabricated films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectrometry (ICP), cyclic voltammetry (CV), and galvanostatic charge/discharge (GC) measurements. It is found that the lithium intercalation/de-intercalation behavior of the Sn film can be significantly improved by its composite with graphite. With cycling, the discharge capacity of the Sn film without composite changes from 570 mAh/g of the 2nd cycle to 270 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 90% and 95%. Nevertheless, the discharge capacity of the composite Sn/C film changes from 575 mAh/g of the 2nd cycle to 515 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 95% and 100%. The performance improvement of tin by its composite with graphite is ascribed to the retardation of the bulk tin cracking from volume change during lithium intercalation and de-intercalation, which leads to the pulverization of tin.
文摘Tribological characteristics of new series of Al Sn Si alloys were investigated by means of pin disk types of wear testing machines, OM, SEM and EDAX. Rules about the influence of Sn, Si content and load on the friction and wear characteristics of the alloys were ascertained. The friction factor and wear rate of the alloys decrease with increasing Sn content, the wear rate decreases but the friction factor varies hardly with increasing Si content. The friction factor of the alloys increases slightly and the wear rate increases observably with increasing load in the range of 1080 N. The wear mechanism of Al Sn Si alloys consists of ‘plough’ action and abrasive wear below 30 N; the adhesive and delamination mechanism are shown in the range of 3080 N. The tribological characteristics of Al Sn Si system are superior to those of Al Sn or Al Si systems due to their “peritectic type” island shape microstructure of Si surrounded with Sn.
基金This project is supported by National Natural Science Foundation of China (No.50275054)Provincial Natural Science Foundation of Guangdong, China (No.020923)Provincial Science and Technology Key Project of Industry of Guangdong, China(No.2003C102013)High Level Construction Project of South China University of Technology, China(No.73056060).
基金Projects(2006A10704003,2006Z3-D2031) supported by the Key Projects of Guangdong Province and Guangzhou City, China
文摘Tin carbon nanotube(Sn-CNTs) composite was prepared by ultrasonic-electrodepositing tin on the substrate of copper foil in a sulfate bath containing carbon nanotubes(CNTs). The composites were characterized by scanning electron microscopy(SEM),cyclic voltammetry(CV) and charge-discharge cycling test. The results show that Sn-CNTs have a better electrochemical performance than Sn. The capacity of Sn-CNTs is 843 mA·h/g during the first discharge and the efficiency of charge-discharge reaches 85%. After 50 cycles,the capacity of Sn-CNTs keeps at 380 mA·h/g. The CNTs in tin act as a structure supporter and play a role of an elastomer and conductive network,alleviating the electrode dilapidation resulted from volume change during the lithium insertion and deinsertion.
基金Supported by the National Natural Science Foundation of China (Grant No. 50372013)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20050562002)the Guangdong Provincial Natural Science Foundation of China (Grant No. 07001769)
文摘Nano-carbon and iron composite―carbon-coated iron nanoparticles (CCINs) produced by carbon arc method can be used as a new kind of magnetic targeting induction heating drug carrier for cancer therapy. The structure and morphology of CCINs are studied by X-ray diffraction (XRD) and transmission electron microscope (TEM). Mossbauer spectra of these nanoparticles show that they contain only iron and carbon, without ferric carbide and ferric oxide. CCINs can be used as the magnetic drug carrier, with the effect of targeting magnetic induction heating in its inner core and higher drug adsorption in its nano-carbon shell outside because of its high specific surface area. CCINs can absorb Epirubicin (EPI) of 160 μg/mg measured by an optical spectrometer. In acute toxicity experiment with mice, the median lethal dose (LD50) of EPI is 16.9 mg/kg, while that of EPI-CCINs mixture is 20.7 mg/kg and none of the mice died after pure CCINs medication. The results show that pure CCINs belong to non-toxic grade and EPI delivery in mixture with CCINs can reduce its acute toxicity in mice. The magnetic properties of CCINs and their magnetic induction heating are investigated. The iron nanoparticle in its inner core has better magnetism with a good effect on targeting magnetic induction heating. When the CCINs are mixed with physiological salt water and are injected uniformly in pig's liver, the temperature goes up to 48℃. While in the case that CCINs are filled in a certain section of pig's liver, the temperature goes up to 52℃. In both cases the temperature is high enough to kill the cancer cell. CCINs have potential applications in cancer therapy.
