Highly ordered and porous anodic aluminum oxide templates were prepared. The ordered copper nanowires arrays were assembled in nano-holes of the template by alternating current electrodeposition at lover voltage. The ...Highly ordered and porous anodic aluminum oxide templates were prepared. The ordered copper nanowires arrays were assembled in nano-holes of the template by alternating current electrodeposition at lover voltage. The morphologies of template and copper nano-wires arrays were characterized by means of field emission scanning electron microscope (FESEM) and the crystal structure of copper nano-wires was determined by means of X-ray diffraction. The results indicate that copper nano-wires hold the preferred crystalline orientation along (111), (200), (220) and (331) crystal faces during growth, and the growth of copper nano-wires in the nano-holes of the template is homogenous and continuous.展开更多
The CaO-doped Cu/（NiFe2O4-10NiO） cermet inert anodes were prepared by the cold isostatie pressing-sintering process, and their corrosion resistance to Na3AlF6-K3AlF6-Al203 melt was studied. The results show that the...The CaO-doped Cu/（NiFe2O4-10NiO） cermet inert anodes were prepared by the cold isostatie pressing-sintering process, and their corrosion resistance to Na3AlF6-K3AlF6-Al203 melt was studied. The results show that the relative density of 5Cu/（NiFe2O4-10NiO） cermet sintered at 1 200 ℃ increases from 82.83% to 97.63% when 2% CaO （mass fraction） is added. During the electrolysis, the relative density of cermet inert anode descends owing to the chemical dissolution of additive CaO at ceramic grain boundary, which accelerates the penetration of electrolyte. Thus, the corrosion resistance to melts of Cu/（NiFe2O4-10NiO） cermet inert anode is reduced. To improve the corrosion resistance of the cermet inert anode, the content of CaO doped should be decreased and the technology of cleaning the ceramic grain boundary should be applied.展开更多
Stress corrosion cracking (SCC) and anticorrosion measures of TU42C weld-joint were studied by constant load experiments and pickling experiments. The results show that in 40%(mass fraction) NaOH solution at 110℃, ca...Stress corrosion cracking (SCC) and anticorrosion measures of TU42C weld-joint were studied by constant load experiments and pickling experiments. The results show that in 40%(mass fraction) NaOH solution at 110℃, caustic SCC occurs in TU42C weld-joints at the applied potential of-1020mV(vs SCE) for 3d while at the potential of-950mV(vs SCE) for 10d. All the cracks are intergranular. In the 10% sulfuric acid, the cracks have the most negative self-corrosion potential-432.5mV(vs SCE) and are active to be further corroded by the acid. Because of the same corrosion behaviour as the lab weldment, preheater’s cracking in alumina factories is attributed to the combining actions of previous caustic SCC in Bayer solutions and continuous acid corrosion by pickling with the addition of RD. The following measures are effective to prevent the corrosion failure of preheater, such as postweld heat treatment at 620℃ to relax the residual weld stress, addition of CC3 and L826 as the corrosion inhibitors to improve the pickling and cleaning by the high pressure water instead of by pickling.展开更多
文摘Highly ordered and porous anodic aluminum oxide templates were prepared. The ordered copper nanowires arrays were assembled in nano-holes of the template by alternating current electrodeposition at lover voltage. The morphologies of template and copper nano-wires arrays were characterized by means of field emission scanning electron microscope (FESEM) and the crystal structure of copper nano-wires was determined by means of X-ray diffraction. The results indicate that copper nano-wires hold the preferred crystalline orientation along (111), (200), (220) and (331) crystal faces during growth, and the growth of copper nano-wires in the nano-holes of the template is homogenous and continuous.
基金Project(2005CB623703) supported by the Major State Basic Research and Development Program of ChinaProject(2008AA030503) supported by Hi-Tech Research and Development Program of China
文摘The CaO-doped Cu/（NiFe2O4-10NiO） cermet inert anodes were prepared by the cold isostatie pressing-sintering process, and their corrosion resistance to Na3AlF6-K3AlF6-Al203 melt was studied. The results show that the relative density of 5Cu/（NiFe2O4-10NiO） cermet sintered at 1 200 ℃ increases from 82.83% to 97.63% when 2% CaO （mass fraction） is added. During the electrolysis, the relative density of cermet inert anode descends owing to the chemical dissolution of additive CaO at ceramic grain boundary, which accelerates the penetration of electrolyte. Thus, the corrosion resistance to melts of Cu/（NiFe2O4-10NiO） cermet inert anode is reduced. To improve the corrosion resistance of the cermet inert anode, the content of CaO doped should be decreased and the technology of cleaning the ceramic grain boundary should be applied.
文摘Stress corrosion cracking (SCC) and anticorrosion measures of TU42C weld-joint were studied by constant load experiments and pickling experiments. The results show that in 40%(mass fraction) NaOH solution at 110℃, caustic SCC occurs in TU42C weld-joints at the applied potential of-1020mV(vs SCE) for 3d while at the potential of-950mV(vs SCE) for 10d. All the cracks are intergranular. In the 10% sulfuric acid, the cracks have the most negative self-corrosion potential-432.5mV(vs SCE) and are active to be further corroded by the acid. Because of the same corrosion behaviour as the lab weldment, preheater’s cracking in alumina factories is attributed to the combining actions of previous caustic SCC in Bayer solutions and continuous acid corrosion by pickling with the addition of RD. The following measures are effective to prevent the corrosion failure of preheater, such as postweld heat treatment at 620℃ to relax the residual weld stress, addition of CC3 and L826 as the corrosion inhibitors to improve the pickling and cleaning by the high pressure water instead of by pickling.
