Molten aluminum is among the most common causes of burns in the metal industry.However,only few reports are available on molten aluminum injuries.Herein,we report an unusual case of molten aluminum burn.The patient ha...Molten aluminum is among the most common causes of burns in the metal industry.However,only few reports are available on molten aluminum injuries.Herein,we report an unusual case of molten aluminum burn.The patient had burns not only on the body surface but also in the respiratory tract and esophagus,adding to the difficulty of treatment.Multidisciplinary consultation and cooperation led to the development of a treatment plan for the patient,which included tracheotomy,respiratory management,endoscopic therapy,infection control,and psychological support.To our knowledge,this is the first report of molten aluminum-induced burns involving the face,neck,respiratory tract,esophagus,and eyes.We also describe our experience with multidisciplinary treatment for the management of molten aluminum burns.展开更多
The failure caused by the corrosion-wear of molten aluminum and its alloys is one of the main problems in aluminum industry. In this work, the resistance behavior of various materials, including Fe-based alloys, ceram...The failure caused by the corrosion-wear of molten aluminum and its alloys is one of the main problems in aluminum industry. In this work, the resistance behavior of various materials, including Fe-based alloys, ceramics and corresponding high apparatus of corrosion-wear in molten aluminum and its alloys, were reviewed. The synergistic effect of corrosion and wear was discussed based on corrosion and wear mechanics. The effects of dynamic agitation due to rotating of friction pairs, physical property of liquid metal and size of grain etc., on the corrosion-wear resistance performance were investigated. In addition, the characteristics of corrosion-wear resistance performance of materials in molten aluminum and its alloy were summarized. According to our recent progress referred to kinds of materials, especially a TiA13/Ti3A1C2/A1203 composite, the ceramics/metal composites with a co-continuous structure will be of great advantage in the field of corrosion-wear environment of molten aluminum and its alloys.展开更多
The corrosion behaviors of 91W-6Ni-3Fe (91W) refractory alloy, TiAl intermetallic compound and two types of iron based alloys (QT700 and H13 tool steel) in a liquid aluminum were investigated. Corrosion experiment...The corrosion behaviors of 91W-6Ni-3Fe (91W) refractory alloy, TiAl intermetallic compound and two types of iron based alloys (QT700 and H13 tool steel) in a liquid aluminum were investigated. Corrosion experiments or static immersion-tests were carried out in pure molten aluminum at 750 ℃. The surface micro-topographies, corrosion interfaces and phase compositions of the immersed samples were investigated by 3D optical microscopy, SEM, EDS and XRD. The results show that 91W exhibits the best corrosion resistance, followed by QT700, H13 and TiAl alloy, consequently. The corrosion mass loss of the four metallic materials adheres to parabolic criterion, and the corrosion rate trends to be stable after initial acceleration. The diffusion-reaction mechanism is proposed for the dissolution of materials in molten aluminum, and the diffusion process is the rate-determining step during the dissolution of 91W in molten aluminum, while the low activation energy for the reaction between TiAl-(TiAl3)-Al couple results in poor corrosion resistance of TiAl alloy in molten aluminum.展开更多
Aluminum doped zinc oxide (AZO), as an electrically conductive material, was applied to coating on the surface of olivine-type LiFePO4 synthesized by solid-state method. The charge-discharge test results show that t...Aluminum doped zinc oxide (AZO), as an electrically conductive material, was applied to coating on the surface of olivine-type LiFePO4 synthesized by solid-state method. The charge-discharge test results show that the rate performance and low-temperature performance of LiFePO4 are greatly improved by the surface treatment. Even at 20C rate, the discharge specific capacity of 100.9 mA.h/g was obtained by the AZO-coated LiFePO4 at room temperature. At -20 ℃, the discharge specific capacity at 0.2C for un-coated LiFePO4 and the coated one are 50.3 mA.h/g and 119.4 mA.h/g, respectively. It should be attributed to the electrically conductive AZO-coating which increases the electronic conductivity of LiFePO4. Furthermore, the surface-coating increases the tap-density of LiFePO4. The results indicate that the AZO-coated LiFePO4 is a good candidate of cathode material for applying in lithium power batteries.展开更多
An FeMo-alloy-doped β-SiA1ON (FeMo/β-SiA1ON) composite was fabricated via a reaction-bonding method using raw materials of Si, Al2O3, A1N, FeMo, and Sm2O3. The effects of FeMo on the microstructure and mechanical ...An FeMo-alloy-doped β-SiA1ON (FeMo/β-SiA1ON) composite was fabricated via a reaction-bonding method using raw materials of Si, Al2O3, A1N, FeMo, and Sm2O3. The effects of FeMo on the microstructure and mechanical properties of the composite were investi- gated. Some properties of the composite, including its bending strength at 700℃ and after oxidization at 700℃ for 24 h in air, thermal shock resistance and corrosion resistance to molten aluminum, were also evaluated. The results show that the density, toughness, bending strength, and thermal shock resistance of the composite are obviously improved with the addition of an FeMo alloy. In addition, other properties of the composite such as its high-temperature strength and oxidized strength are also improved by the addition of FeMo alloy, and its corrosion re- sistance to molten aluminum is maintained. These findings indicate that the developed FeMo/β-SiA1ON composite exhibits strong potential for application to molten aluminum environments.展开更多
Thanks to low cost,high safety,and large energy density,aqueous zinc-ion batteries have attracted tremendous interest worldwide.However,it remains a challenge to develop high-performance cathode materials with an appr...Thanks to low cost,high safety,and large energy density,aqueous zinc-ion batteries have attracted tremendous interest worldwide.However,it remains a challenge to develop high-performance cathode materials with an appropriate method that is easy to realize massive production.Herein,we use a molten salt method to synthesize nanostructured manganese oxides.The crystalline phases of the manganese oxides can be tuned by changing the amount of reduced graphene oxide added to the reactant mixture.It is found that the α-MnO_(2)/Mn_(2)O_(3) nanocomposite with the largest mass ratio of Mn_(2)O_(3) delivers the best electrochemical performances among all the products.And its rate capability and cyclability can be significantly improved by modifying the Zn anode with carbon black coating and nanocellulose binder.In this situation,the nanocomposite can deliver high discharging capacities of 322.1 and 213.6 mAh g^(-1) at 0.2 and 3 Ag^(-1),respectively.After 1000 cycles,it can retain 86.2% of the capacity at the 2 nd cycle.Thus,this nanocomposite holds great promise for practical applications.展开更多
Hydrogen partial pressure is an important parameter to calculate hydrogen concentration levels in molten aluminum alloy. A new dynamic method for measuring hydrogen partial pressure in molten aluminum alloy is studied...Hydrogen partial pressure is an important parameter to calculate hydrogen concentration levels in molten aluminum alloy. A new dynamic method for measuring hydrogen partial pressure in molten aluminum alloy is studied. Dynamic and rapid measurement is realized through changing the volume of the vacuum chamber and calculating the pressure difference ΔP between the theoretical and measured pressures in the vacuum chamber. Positive ΔP indicates hydrogen transmits from melt to vacuum chamber and negative ΔP means the reverse. When ΔP is equal to zero, hydrogen transmitted from both sides reached a state of dynamical equilibrium and the pressure in the vacuum chamber is equal to the hydrogen partial pressure in the molten aluminum alloy. Compared with other existing measuring methods, the new method can significantly shorten the testing time and reduce measuring cost.展开更多
The components of the equipment for processing the Al melts into the molded parts can be markedly corroded by the molten Al. In this study, a 4 μm CrN coating or CrN/TiN multilayer coating for providing the physical ...The components of the equipment for processing the Al melts into the molded parts can be markedly corroded by the molten Al. In this study, a 4 μm CrN coating or CrN/TiN multilayer coating for providing the physical and chemical barriers between the molten reactive Al and the steel substrate were deposited by Cathodic Arc Evaporation onto 10 mm-thick heat-resistant steel plates. The dipping tests were conducted in a 700℃ A356 melt for 1 to 21 h at intervals of 3 h. The damage of the coated steel was eva...展开更多
Zinc supplementation can help maintain learning and memory function in rodents. In this study, we hypothesized that zinc supplementation could antagonize the neurotoxicity induced by aluminum in rats. Animals were fed...Zinc supplementation can help maintain learning and memory function in rodents. In this study, we hypothesized that zinc supplementation could antagonize the neurotoxicity induced by aluminum in rats. Animals were fed a diet containing different doses of zinc (50, 100, 200 mg/kg) for 9 weeks, and orally administered aluminum chloride (300 mg/kg daily) from the third week for 7 consecutive weeks. Open-field behavioral test results showed that the number of rearings in the group given the 100 mg/kg zinc supplement was significantly increased compared with the group given the 50 mg/kg zinc supplement. Malondialdehyde content in the cerebrum was significantly decreased, while dopamine and 5-hydroxytryptamine levels were increased in the groups given the diet sup- plemented with 100 and 200 mg/kg zinc, compared with the group given the diet supplemented with 50 mg/kg zinc. The acetylcholinesterase activity in the cerebrum was significantly decreased in the group given the 100 mg/kg zinc supplement. Hematoxylin-eosin staining revealed evident patho- logical damage in the hippocampus of rats in the group given the diet supplemented with 50 mg/kg zinc, but the damage was attenuated in the groups given the diet supplemented with 100 and 200 mg/kg zinc. Our findings suggest that zinc is a potential neuroprotective agent against alumi-num-induced neurotoxicity in rats, and the optimal dosages are 100 and 200 mg/kg.展开更多
The interaction of oxide film with molten flux during aluminum brazing has been studied by means of X-ray powder diffraction. The following conclusions have been deduced: The swell- ing of aluminum oxide film is cause...The interaction of oxide film with molten flux during aluminum brazing has been studied by means of X-ray powder diffraction. The following conclusions have been deduced: The swell- ing of aluminum oxide film is caused by Li^+ inserting into the vacancies of octahedral or tetrahedral structure of 0 atom skeleton in у-Al_2O_3 . The strength of oxide film decreases as the crytallinity increases by the treating of flux containing LiF.展开更多
The electrodeposition of aluminum(Al)was studied using two electrolyte solutions,such as anhydrous AlCl3-urea and hydrated AlCl3·6 H2 O-urea.A systematic examination using cell voltages 1.0–2.0 V was carried out...The electrodeposition of aluminum(Al)was studied using two electrolyte solutions,such as anhydrous AlCl3-urea and hydrated AlCl3·6 H2 O-urea.A systematic examination using cell voltages 1.0–2.0 V was carried out at temperatures((50–100)±2)°C.A needle-shaped cathode was employed for the deposition of aluminum.A dendrite and particulate microstructure of Al were observed on the needle-shaped cathode.An improved condition for the manufacturing of small sizes and high purity of aluminum deposits was obtained.Pure Al with a current efficiency(yield)of 84%–99%was obtained from those of non-aqueous electrolytes and only of 8.6%–9.3%from those of hydrated electrolytes.The electrical conductivities of electrolytes remained considerable at((50–100)±2)°C.The improved aluminum powders were used for the reaction with water.The aluminum reacts with water at room temperature,producing pure H2 with 100%yield.The electrodeposited aluminum metal can be used as an excellent energy carrier.展开更多
The injection of nitrogen in molten aluminum through a static impeller in a tank degassing unit is studied. Using basic principles of fluid mechanics, it is analyzed the influence of the nozzle diameter on the bubble ...The injection of nitrogen in molten aluminum through a static impeller in a tank degassing unit is studied. Using basic principles of fluid mechanics, it is analyzed the influence of the nozzle diameter on the bubble diameter and the mean residence time of the bubbles in the molten aluminum. By means of transient isothermal 2D Computational Fluid Dynamics (CFD) simulations, the influence of the nitrogen volumetric flow rate on the phase distributions and the tank degasser dynamics is studied. Finally, an adiabatic CFD simulation is carried out in order to elucidate the changes in the molten aluminum temperature due to the injection of nitrogen at ambient temperature. This simulation shows that molten aluminum does not suffer drastic temperature reductions given that, in spite?that?the nitrogen is fed at ambient temperature, the mass of nitrogen is relatively small compared with the mass of aluminum.展开更多
Rechargeable aqueous zinc-ion batteries(AZIBs)have their unique advantages of cost efficiency,high safety,and environmental friendliness.However,challenges facing the cathode materials include whether they can remain ...Rechargeable aqueous zinc-ion batteries(AZIBs)have their unique advantages of cost efficiency,high safety,and environmental friendliness.However,challenges facing the cathode materials include whether they can remain chemically stable in aqueous electrolyte and provide a robust structure for the storage of Zn2+.Here,we report on H11Al2V6O23.2@graphene(HAVO@G)with exceptionally large layer spacing of(001)plane(13.36?).The graphene-wrapped structure can keep the structure stable during discharge/charge process,thereby promoting the inhibition of the dissolution of elements in the aqueous electrolyte.While used as cathode for AZIBs,HAVO@G electrode delivers ideal rate performance(reversible capacity of 305.4,276.6,230.0,201.7,180.6 mAh g?1 at current densities between 1 and 10 A g?1).Remarkably,the electrode exhibits excellent and stable cycling stability even at a high loading mass of^15.7 mg cm?2,with an ideal reversible capacity of 131.7 mAh g?1 after 400 cycles at 2 A g?1.展开更多
Sintered zinc aluminum coating (SZAC) was prepared using zinc flakes, aluminum flakes and CrO 3 as main raw materials. The corrosion behavior of SZAC in 3.5%NaCl solution was studied by means of SEM, EDS, EIS and so o...Sintered zinc aluminum coating (SZAC) was prepared using zinc flakes, aluminum flakes and CrO 3 as main raw materials. The corrosion behavior of SZAC in 3.5%NaCl solution was studied by means of SEM, EDS, EIS and so on. Results indicate that aluminum corroded in advance of zinc to produce speculate or spherical substances, which attaches to SZAC and adds mass to it. Corrosion production passivates metal powders in SZAC, causes E corr of SZAC to increase gradually, and causes the arising of the third time constant in EIS, which corresponds to the insulation of corrosion production.展开更多
Removal of inclusions from industrial pure molten aluminum(A01) by stirring active molten flux was studied. Wettability of nonmetallic inclusions in the molten aluminum was worse than that in active molten flux. Accor...Removal of inclusions from industrial pure molten aluminum(A01) by stirring active molten flux was studied. Wettability of nonmetallic inclusions in the molten aluminum was worse than that in active molten flux. According to the surface renewal model, the inclusions were easily transferred into molten active flux from fine aluminum droplets and then reacted chemically when molten aluminum was dispersed into fine aluminum droplets in stirring active molten flux. Tensile tests show that tensile strength of purified tensile sample(as-cast) increases by 8.59%. SEM photographs show that the fracture cracks of purified tensile sample are homogeneous, and the dimples are small and homogeneous. From metallographs and statistic results of Leco analysis software, it is found that the quantities and sizes of the inclusions in purified sample are obviously fewer and smaller than in unpurified tensile sample(as-cast).展开更多
Corrosion resistance of ceramic substrate glazes to molten aluminum was studied in this paper. The glazes can spread slightly in aluminum alloy according to SEM examination of solidified interface between the glazes a...Corrosion resistance of ceramic substrate glazes to molten aluminum was studied in this paper. The glazes can spread slightly in aluminum alloy according to SEM examination of solidified interface between the glazes and aluminum alloy. The components of B2O3-P2O5 glazes were not detected with electron probe at the side of aluminum alloy near the interface, but the components of boron-free glaze were detected. It is shown that borophosphate glazes can resist the corrosion of molten aluminum.展开更多
ZA27 alloy has the best performance and the widest applications in high aluminum zinc based die casting alloy series. One of its main applica-tions is used as abrasion resistant alloy,instead of nonferrous alloys such...ZA27 alloy has the best performance and the widest applications in high aluminum zinc based die casting alloy series. One of its main applica-tions is used as abrasion resistant alloy,instead of nonferrous alloys such as copper alloy.The frictional wear p展开更多
Low-frequency noise(LFN) in all operation regions of amorphous indium zinc oxide(a-IZO) thin film transistors(TFTs) with an aluminum oxide gate insulator is investigated. Based on the LFN measured results, we ex...Low-frequency noise(LFN) in all operation regions of amorphous indium zinc oxide(a-IZO) thin film transistors(TFTs) with an aluminum oxide gate insulator is investigated. Based on the LFN measured results, we extract the distribution of localized states in the band gap and the spatial distribution of border traps in the gate dielectric,and study the dependence of measured noise on the characteristic temperature of localized states for a-IZO TFTs with Al2 O3 gate dielectric. Further study on the LFN measured results shows that the gate voltage dependent noise data closely obey the mobility fluctuation model, and the average Hooge's parameter is about 1.18×10^-3.Considering the relationship between the free carrier number and the field effect mobility, we simulate the LFN using the △N-△μ model, and the total trap density near the IZO/oxide interface is about 1.23×10^18 cm^-3eV^-1.展开更多
Molten aluminum (A001) was filtered by using ceramic foam filters coated with active enamel. Tensile test shows that the elongation of filtered sample is increased by 15.5%, but the tensile strength of the sample is a...Molten aluminum (A001) was filtered by using ceramic foam filters coated with active enamel. Tensile test shows that the elongation of filtered sample is increased by 15.5%, but the tensile strength of the sample is almost the same as that of unfiltered one. The fracture cracks and dimples of filtered sample are fine and homogeneous according to SEM examination. In addition, metallographic observation shows that the filtered sample has very few inclusions of approximately 8 μm in diameter, but the unfiltered sample has some inclusions of approximately 60 μm in length and 20 μm in width. However, it is suggested that the active enamel coat can effectively capture the inclusions and dissolve them during filtering molten aluminum.展开更多
A protecting zinc and aluminum coating on the surface of AZ91D magnesium alloys was obtained by thermal spraying to improve the corrosion and wear resistance performances. In order to enhance the combination between m...A protecting zinc and aluminum coating on the surface of AZ91D magnesium alloys was obtained by thermal spraying to improve the corrosion and wear resistance performances. In order to enhance the combination between magnesium alloy matrix and zinc and aluminum coating, the sample was heat-treated at 300℃for 2 h, then, the cross-section patterns, XRD pattern, micro-hardness, wear and corrosion resistance abilities were researched. The results indicate that the interface between the coating and substrate is metallurgical bond, and a transitional fusion layer is formed by diffusion. The micro-scale abrasion test and polarization test in 3% NaCl solution show that the diffusion-treated specimen has better wear and corrosion resistance performances in comparison with the undiffusion-treated and substrate magnesium alloys; in addition, it has relatively higher micro-hardness than the undiffusion-treated magnesium alloys.展开更多
基金supported by the Biomaterials and Regenerative Medicine Institute Cooperative Research Project at Shanghai Jiao Tong University School of Medicine(grant no.2022LHA05)the Shanghai Clinical Research Center of Plastic and Reconstructive Surgery funded by the Science and Technology Commission of Shanghai Municipality(grant no.22Mc1940300).
文摘Molten aluminum is among the most common causes of burns in the metal industry.However,only few reports are available on molten aluminum injuries.Herein,we report an unusual case of molten aluminum burn.The patient had burns not only on the body surface but also in the respiratory tract and esophagus,adding to the difficulty of treatment.Multidisciplinary consultation and cooperation led to the development of a treatment plan for the patient,which included tracheotomy,respiratory management,endoscopic therapy,infection control,and psychological support.To our knowledge,this is the first report of molten aluminum-induced burns involving the face,neck,respiratory tract,esophagus,and eyes.We also describe our experience with multidisciplinary treatment for the management of molten aluminum burns.
基金Project(51271080) supported by the National Natural Science Foundation of China
文摘The failure caused by the corrosion-wear of molten aluminum and its alloys is one of the main problems in aluminum industry. In this work, the resistance behavior of various materials, including Fe-based alloys, ceramics and corresponding high apparatus of corrosion-wear in molten aluminum and its alloys, were reviewed. The synergistic effect of corrosion and wear was discussed based on corrosion and wear mechanics. The effects of dynamic agitation due to rotating of friction pairs, physical property of liquid metal and size of grain etc., on the corrosion-wear resistance performance were investigated. In addition, the characteristics of corrosion-wear resistance performance of materials in molten aluminum and its alloy were summarized. According to our recent progress referred to kinds of materials, especially a TiA13/Ti3A1C2/A1203 composite, the ceramics/metal composites with a co-continuous structure will be of great advantage in the field of corrosion-wear environment of molten aluminum and its alloys.
基金Project (51271080) supported by the National Natural Science Foundation of ChinaProject (S2011010002227) supported by the Natural Science Foundation of Guangdong Province, ChinaProject (20100172110033) supported by the Specialized Research Fund for the Doctoral Program of Higher Education
文摘The corrosion behaviors of 91W-6Ni-3Fe (91W) refractory alloy, TiAl intermetallic compound and two types of iron based alloys (QT700 and H13 tool steel) in a liquid aluminum were investigated. Corrosion experiments or static immersion-tests were carried out in pure molten aluminum at 750 ℃. The surface micro-topographies, corrosion interfaces and phase compositions of the immersed samples were investigated by 3D optical microscopy, SEM, EDS and XRD. The results show that 91W exhibits the best corrosion resistance, followed by QT700, H13 and TiAl alloy, consequently. The corrosion mass loss of the four metallic materials adheres to parabolic criterion, and the corrosion rate trends to be stable after initial acceleration. The diffusion-reaction mechanism is proposed for the dissolution of materials in molten aluminum, and the diffusion process is the rate-determining step during the dissolution of 91W in molten aluminum, while the low activation energy for the reaction between TiAl-(TiAl3)-Al couple results in poor corrosion resistance of TiAl alloy in molten aluminum.
文摘Aluminum doped zinc oxide (AZO), as an electrically conductive material, was applied to coating on the surface of olivine-type LiFePO4 synthesized by solid-state method. The charge-discharge test results show that the rate performance and low-temperature performance of LiFePO4 are greatly improved by the surface treatment. Even at 20C rate, the discharge specific capacity of 100.9 mA.h/g was obtained by the AZO-coated LiFePO4 at room temperature. At -20 ℃, the discharge specific capacity at 0.2C for un-coated LiFePO4 and the coated one are 50.3 mA.h/g and 119.4 mA.h/g, respectively. It should be attributed to the electrically conductive AZO-coating which increases the electronic conductivity of LiFePO4. Furthermore, the surface-coating increases the tap-density of LiFePO4. The results indicate that the AZO-coated LiFePO4 is a good candidate of cathode material for applying in lithium power batteries.
基金financially supported by the National Natural Science Foundation of China (No. 51272208)the Program for New Century Excellent Talents in University (NCET–12–0454)the Program for Young Excellent Talents in Shaanxi Province, China (2013KJXX–50)
文摘An FeMo-alloy-doped β-SiA1ON (FeMo/β-SiA1ON) composite was fabricated via a reaction-bonding method using raw materials of Si, Al2O3, A1N, FeMo, and Sm2O3. The effects of FeMo on the microstructure and mechanical properties of the composite were investi- gated. Some properties of the composite, including its bending strength at 700℃ and after oxidization at 700℃ for 24 h in air, thermal shock resistance and corrosion resistance to molten aluminum, were also evaluated. The results show that the density, toughness, bending strength, and thermal shock resistance of the composite are obviously improved with the addition of an FeMo alloy. In addition, other properties of the composite such as its high-temperature strength and oxidized strength are also improved by the addition of FeMo alloy, and its corrosion re- sistance to molten aluminum is maintained. These findings indicate that the developed FeMo/β-SiA1ON composite exhibits strong potential for application to molten aluminum environments.
基金funded by the National Natural Science Foundation of China(No.51902165)the Natural Science Foundation of Jiangsu Province(No.BK20170917)+2 种基金the Scientific Research Foundation for High-Level Talents of Nanjing Forestry University(No.GXL2016023)the Program of High-Level Talents in Six Industries of Jiangsu Province(No.XCL-040)the Jiangsu Specially-Appointed Professor Program。
文摘Thanks to low cost,high safety,and large energy density,aqueous zinc-ion batteries have attracted tremendous interest worldwide.However,it remains a challenge to develop high-performance cathode materials with an appropriate method that is easy to realize massive production.Herein,we use a molten salt method to synthesize nanostructured manganese oxides.The crystalline phases of the manganese oxides can be tuned by changing the amount of reduced graphene oxide added to the reactant mixture.It is found that the α-MnO_(2)/Mn_(2)O_(3) nanocomposite with the largest mass ratio of Mn_(2)O_(3) delivers the best electrochemical performances among all the products.And its rate capability and cyclability can be significantly improved by modifying the Zn anode with carbon black coating and nanocellulose binder.In this situation,the nanocomposite can deliver high discharging capacities of 322.1 and 213.6 mAh g^(-1) at 0.2 and 3 Ag^(-1),respectively.After 1000 cycles,it can retain 86.2% of the capacity at the 2 nd cycle.Thus,this nanocomposite holds great promise for practical applications.
文摘Hydrogen partial pressure is an important parameter to calculate hydrogen concentration levels in molten aluminum alloy. A new dynamic method for measuring hydrogen partial pressure in molten aluminum alloy is studied. Dynamic and rapid measurement is realized through changing the volume of the vacuum chamber and calculating the pressure difference ΔP between the theoretical and measured pressures in the vacuum chamber. Positive ΔP indicates hydrogen transmits from melt to vacuum chamber and negative ΔP means the reverse. When ΔP is equal to zero, hydrogen transmitted from both sides reached a state of dynamical equilibrium and the pressure in the vacuum chamber is equal to the hydrogen partial pressure in the molten aluminum alloy. Compared with other existing measuring methods, the new method can significantly shorten the testing time and reduce measuring cost.
文摘The components of the equipment for processing the Al melts into the molded parts can be markedly corroded by the molten Al. In this study, a 4 μm CrN coating or CrN/TiN multilayer coating for providing the physical and chemical barriers between the molten reactive Al and the steel substrate were deposited by Cathodic Arc Evaporation onto 10 mm-thick heat-resistant steel plates. The dipping tests were conducted in a 700℃ A356 melt for 1 to 21 h at intervals of 3 h. The damage of the coated steel was eva...
基金was funded by the National Nature Science Foundation of China,No.30872098,30901185the National Nature Science Foundation of Tianjin,No.05YFJMJC 05500the Medical Science and Technology Project of Chinese PLA,No.13QNP069.
文摘Zinc supplementation can help maintain learning and memory function in rodents. In this study, we hypothesized that zinc supplementation could antagonize the neurotoxicity induced by aluminum in rats. Animals were fed a diet containing different doses of zinc (50, 100, 200 mg/kg) for 9 weeks, and orally administered aluminum chloride (300 mg/kg daily) from the third week for 7 consecutive weeks. Open-field behavioral test results showed that the number of rearings in the group given the 100 mg/kg zinc supplement was significantly increased compared with the group given the 50 mg/kg zinc supplement. Malondialdehyde content in the cerebrum was significantly decreased, while dopamine and 5-hydroxytryptamine levels were increased in the groups given the diet sup- plemented with 100 and 200 mg/kg zinc, compared with the group given the diet supplemented with 50 mg/kg zinc. The acetylcholinesterase activity in the cerebrum was significantly decreased in the group given the 100 mg/kg zinc supplement. Hematoxylin-eosin staining revealed evident patho- logical damage in the hippocampus of rats in the group given the diet supplemented with 50 mg/kg zinc, but the damage was attenuated in the groups given the diet supplemented with 100 and 200 mg/kg zinc. Our findings suggest that zinc is a potential neuroprotective agent against alumi-num-induced neurotoxicity in rats, and the optimal dosages are 100 and 200 mg/kg.
文摘The interaction of oxide film with molten flux during aluminum brazing has been studied by means of X-ray powder diffraction. The following conclusions have been deduced: The swell- ing of aluminum oxide film is caused by Li^+ inserting into the vacancies of octahedral or tetrahedral structure of 0 atom skeleton in у-Al_2O_3 . The strength of oxide film decreases as the crytallinity increases by the treating of flux containing LiF.
基金the financial support from Ministry of Science and Technology,Taiwan,China Grant number:MOST 106-2113-M-033-008。
文摘The electrodeposition of aluminum(Al)was studied using two electrolyte solutions,such as anhydrous AlCl3-urea and hydrated AlCl3·6 H2 O-urea.A systematic examination using cell voltages 1.0–2.0 V was carried out at temperatures((50–100)±2)°C.A needle-shaped cathode was employed for the deposition of aluminum.A dendrite and particulate microstructure of Al were observed on the needle-shaped cathode.An improved condition for the manufacturing of small sizes and high purity of aluminum deposits was obtained.Pure Al with a current efficiency(yield)of 84%–99%was obtained from those of non-aqueous electrolytes and only of 8.6%–9.3%from those of hydrated electrolytes.The electrical conductivities of electrolytes remained considerable at((50–100)±2)°C.The improved aluminum powders were used for the reaction with water.The aluminum reacts with water at room temperature,producing pure H2 with 100%yield.The electrodeposited aluminum metal can be used as an excellent energy carrier.
文摘The injection of nitrogen in molten aluminum through a static impeller in a tank degassing unit is studied. Using basic principles of fluid mechanics, it is analyzed the influence of the nozzle diameter on the bubble diameter and the mean residence time of the bubbles in the molten aluminum. By means of transient isothermal 2D Computational Fluid Dynamics (CFD) simulations, the influence of the nitrogen volumetric flow rate on the phase distributions and the tank degasser dynamics is studied. Finally, an adiabatic CFD simulation is carried out in order to elucidate the changes in the molten aluminum temperature due to the injection of nitrogen at ambient temperature. This simulation shows that molten aluminum does not suffer drastic temperature reductions given that, in spite?that?the nitrogen is fed at ambient temperature, the mass of nitrogen is relatively small compared with the mass of aluminum.
基金supported by National Natural Science Foundation of China(Nos.51972346,51932011,51802356,and 51872334)Innovation-Driven Project of Central South University(No.2018CX004).
文摘Rechargeable aqueous zinc-ion batteries(AZIBs)have their unique advantages of cost efficiency,high safety,and environmental friendliness.However,challenges facing the cathode materials include whether they can remain chemically stable in aqueous electrolyte and provide a robust structure for the storage of Zn2+.Here,we report on H11Al2V6O23.2@graphene(HAVO@G)with exceptionally large layer spacing of(001)plane(13.36?).The graphene-wrapped structure can keep the structure stable during discharge/charge process,thereby promoting the inhibition of the dissolution of elements in the aqueous electrolyte.While used as cathode for AZIBs,HAVO@G electrode delivers ideal rate performance(reversible capacity of 305.4,276.6,230.0,201.7,180.6 mAh g?1 at current densities between 1 and 10 A g?1).Remarkably,the electrode exhibits excellent and stable cycling stability even at a high loading mass of^15.7 mg cm?2,with an ideal reversible capacity of 131.7 mAh g?1 after 400 cycles at 2 A g?1.
文摘Sintered zinc aluminum coating (SZAC) was prepared using zinc flakes, aluminum flakes and CrO 3 as main raw materials. The corrosion behavior of SZAC in 3.5%NaCl solution was studied by means of SEM, EDS, EIS and so on. Results indicate that aluminum corroded in advance of zinc to produce speculate or spherical substances, which attaches to SZAC and adds mass to it. Corrosion production passivates metal powders in SZAC, causes E corr of SZAC to increase gradually, and causes the arising of the third time constant in EIS, which corresponds to the insulation of corrosion production.
文摘Removal of inclusions from industrial pure molten aluminum(A01) by stirring active molten flux was studied. Wettability of nonmetallic inclusions in the molten aluminum was worse than that in active molten flux. According to the surface renewal model, the inclusions were easily transferred into molten active flux from fine aluminum droplets and then reacted chemically when molten aluminum was dispersed into fine aluminum droplets in stirring active molten flux. Tensile tests show that tensile strength of purified tensile sample(as-cast) increases by 8.59%. SEM photographs show that the fracture cracks of purified tensile sample are homogeneous, and the dimples are small and homogeneous. From metallographs and statistic results of Leco analysis software, it is found that the quantities and sizes of the inclusions in purified sample are obviously fewer and smaller than in unpurified tensile sample(as-cast).
基金supported by the National Key Fundamental Research Project(973)(Project G1999064900).
文摘Corrosion resistance of ceramic substrate glazes to molten aluminum was studied in this paper. The glazes can spread slightly in aluminum alloy according to SEM examination of solidified interface between the glazes and aluminum alloy. The components of B2O3-P2O5 glazes were not detected with electron probe at the side of aluminum alloy near the interface, but the components of boron-free glaze were detected. It is shown that borophosphate glazes can resist the corrosion of molten aluminum.
文摘ZA27 alloy has the best performance and the widest applications in high aluminum zinc based die casting alloy series. One of its main applica-tions is used as abrasion resistant alloy,instead of nonferrous alloys such as copper alloy.The frictional wear p
基金Supported by the National Natural Science Foundation of China under Grant No 61574048the Science and Technology Research Project of Guangdong Province under Grant Nos 2015B090912002 and 2015B090901048the Pearl River S&T Nova Program of Guangzhou under Grant No 201710010172
文摘Low-frequency noise(LFN) in all operation regions of amorphous indium zinc oxide(a-IZO) thin film transistors(TFTs) with an aluminum oxide gate insulator is investigated. Based on the LFN measured results, we extract the distribution of localized states in the band gap and the spatial distribution of border traps in the gate dielectric,and study the dependence of measured noise on the characteristic temperature of localized states for a-IZO TFTs with Al2 O3 gate dielectric. Further study on the LFN measured results shows that the gate voltage dependent noise data closely obey the mobility fluctuation model, and the average Hooge's parameter is about 1.18×10^-3.Considering the relationship between the free carrier number and the field effect mobility, we simulate the LFN using the △N-△μ model, and the total trap density near the IZO/oxide interface is about 1.23×10^18 cm^-3eV^-1.
文摘Molten aluminum (A001) was filtered by using ceramic foam filters coated with active enamel. Tensile test shows that the elongation of filtered sample is increased by 15.5%, but the tensile strength of the sample is almost the same as that of unfiltered one. The fracture cracks and dimples of filtered sample are fine and homogeneous according to SEM examination. In addition, metallographic observation shows that the filtered sample has very few inclusions of approximately 8 μm in diameter, but the unfiltered sample has some inclusions of approximately 60 μm in length and 20 μm in width. However, it is suggested that the active enamel coat can effectively capture the inclusions and dissolve them during filtering molten aluminum.
基金Projects(2005BB4079, 2004BA4002) supported by the Natural Science Foundation of Chongqing City,China
文摘A protecting zinc and aluminum coating on the surface of AZ91D magnesium alloys was obtained by thermal spraying to improve the corrosion and wear resistance performances. In order to enhance the combination between magnesium alloy matrix and zinc and aluminum coating, the sample was heat-treated at 300℃for 2 h, then, the cross-section patterns, XRD pattern, micro-hardness, wear and corrosion resistance abilities were researched. The results indicate that the interface between the coating and substrate is metallurgical bond, and a transitional fusion layer is formed by diffusion. The micro-scale abrasion test and polarization test in 3% NaCl solution show that the diffusion-treated specimen has better wear and corrosion resistance performances in comparison with the undiffusion-treated and substrate magnesium alloys; in addition, it has relatively higher micro-hardness than the undiffusion-treated magnesium alloys.