We have prepared ordered porous alumina membrane. Metal Zn was deposited within the pores of alumina membrane by direct current. The alumina membrane with Zn in the pores was immersed in HgCl 2 solution and Hg 2Cl 2/A...We have prepared ordered porous alumina membrane. Metal Zn was deposited within the pores of alumina membrane by direct current. The alumina membrane with Zn in the pores was immersed in HgCl 2 solution and Hg 2Cl 2/Al 2O 3 ordered array was synthesized by utilizing Zn reduced HgCl 2. The XRD and TEM measuring demonstrated Hg 2Cl 2 located in the pores of alumina membrane and the diameters range from 30 to 80 nm.展开更多
Al2O3-13%TiO2 （mass fraction） coatings, prepared by laser cladding on nickel-based alloy, were heated using high frequency induction sources. The coating microstructure and the interface between bond coating and cer...Al2O3-13%TiO2 （mass fraction） coatings, prepared by laser cladding on nickel-based alloy, were heated using high frequency induction sources. The coating microstructure and the interface between bond coating and ceramic coating were characterized by SEM, XRD and EDS. The results show that two-layer substructure exists in the ceramic coating： one layer evolving from fully melted region where the sintered grains grow fully; another layer resembling the liquid-phase-sintered structure consisting of three-dimensional net where the melted Al2O3 particles are embedded in the TiO2-rich matrix. The mechanism of the two-layer substructure formation is also explained in terms of the melting and flattening behavior of the powders during laser cladding processing. The spinel compounds NiAl2O4 and acicular compounds Cr2O3 are discovered in the interface between bond coating and ceramic coating. It proves that the chemical reactions in the laser cladding process will significantly enhance the coating adhesion.展开更多
The formation conditions of C, Al4C3 and Al2O3 in the Al Cl disproportionation process in vacuum to produce aluminum was investigated by thermodynamics analysis. It is demonstrated that the required temperatures for t...The formation conditions of C, Al4C3 and Al2O3 in the Al Cl disproportionation process in vacuum to produce aluminum was investigated by thermodynamics analysis. It is demonstrated that the required temperatures for the reactions to form these impurities, the disproportionation of CO and the reactions of metallic aluminum with CO, decrease with decreasing pressure. The lg pCO-1/T diagram of metallic aluminum-CO system agrees with the experimental results, indicating that the reaction rate is very high and this system in vacuum is approximately in equilibrium; therefore, the equilibrium diagram can be used to predict the possible reactions in this system in vacuum.展开更多
Al2O3p-Al composites were synthesized using an in-situ reaction in the 80%Al-20%CuO （mass fraction） system. The effects of the CuO particle size on the synthesis temperature and microstructure of the composites were...Al2O3p-Al composites were synthesized using an in-situ reaction in the 80%Al-20%CuO （mass fraction） system. The effects of the CuO particle size on the synthesis temperature and microstructure of the composites were investigated by various methods. The results indicate that the CuO particle size has a significant effect on the temperature at which the complete reaction in the Al-CuO system occurs：the temperature is 200 ℃ lower in the Al-CuO system containing CuO particles with sizes less than 6μm than that containing CuO particles with sizes less than 100μm. The interfacial bonding between Al2O3 particles and Al is not complete when the temperature is below a critical value. The morphology of the Al2O3 particles varies from ribbon-like shape to near spherical shape when the temperature is above a critical value. These two critical temperatures are affected by the particle size of CuO, and the critical temperature of the sample containing CuO particles with sizes less than 6μm is 100 ℃ lower than that of the sample containing CuO particles with sizes less than 100μm.展开更多
文摘We have prepared ordered porous alumina membrane. Metal Zn was deposited within the pores of alumina membrane by direct current. The alumina membrane with Zn in the pores was immersed in HgCl 2 solution and Hg 2Cl 2/Al 2O 3 ordered array was synthesized by utilizing Zn reduced HgCl 2. The XRD and TEM measuring demonstrated Hg 2Cl 2 located in the pores of alumina membrane and the diameters range from 30 to 80 nm.
基金Project (59975046) supported by the National Natural Science Foundation of China
文摘Al2O3-13%TiO2 （mass fraction） coatings, prepared by laser cladding on nickel-based alloy, were heated using high frequency induction sources. The coating microstructure and the interface between bond coating and ceramic coating were characterized by SEM, XRD and EDS. The results show that two-layer substructure exists in the ceramic coating： one layer evolving from fully melted region where the sintered grains grow fully; another layer resembling the liquid-phase-sintered structure consisting of three-dimensional net where the melted Al2O3 particles are embedded in the TiO2-rich matrix. The mechanism of the two-layer substructure formation is also explained in terms of the melting and flattening behavior of the powders during laser cladding processing. The spinel compounds NiAl2O4 and acicular compounds Cr2O3 are discovered in the interface between bond coating and ceramic coating. It proves that the chemical reactions in the laser cladding process will significantly enhance the coating adhesion.
基金Project(51364020)supported by the National Natural Science Foundation of China
文摘The formation conditions of C, Al4C3 and Al2O3 in the Al Cl disproportionation process in vacuum to produce aluminum was investigated by thermodynamics analysis. It is demonstrated that the required temperatures for the reactions to form these impurities, the disproportionation of CO and the reactions of metallic aluminum with CO, decrease with decreasing pressure. The lg pCO-1/T diagram of metallic aluminum-CO system agrees with the experimental results, indicating that the reaction rate is very high and this system in vacuum is approximately in equilibrium; therefore, the equilibrium diagram can be used to predict the possible reactions in this system in vacuum.
基金Project(2012MS0801)supported by the Natural Science Foundation of Inner Mongolia,China
文摘Al2O3p-Al composites were synthesized using an in-situ reaction in the 80%Al-20%CuO （mass fraction） system. The effects of the CuO particle size on the synthesis temperature and microstructure of the composites were investigated by various methods. The results indicate that the CuO particle size has a significant effect on the temperature at which the complete reaction in the Al-CuO system occurs：the temperature is 200 ℃ lower in the Al-CuO system containing CuO particles with sizes less than 6μm than that containing CuO particles with sizes less than 100μm. The interfacial bonding between Al2O3 particles and Al is not complete when the temperature is below a critical value. The morphology of the Al2O3 particles varies from ribbon-like shape to near spherical shape when the temperature is above a critical value. These two critical temperatures are affected by the particle size of CuO, and the critical temperature of the sample containing CuO particles with sizes less than 6μm is 100 ℃ lower than that of the sample containing CuO particles with sizes less than 100μm.
