The corrosion inhibition property of PEG600 and In（OH）3 as composite corrosion inhibitors for （second-）（ary） alkaline zinc electrodes was studied, and the inhibition efficiency was determined as 81.9%. The resea...The corrosion inhibition property of PEG600 and In（OH）3 as composite corrosion inhibitors for （second-）（ary） alkaline zinc electrodes was studied, and the inhibition efficiency was determined as 81.9%. The research focused on the mechanism by the methods of electrochemical impedance spectroscopy, polarization curves and IR spectroscopy. The results indicate that the corrosion inhibition effectiveness is attributed to the joint inhibition of anodic zinc dissolution and cathodic hydrogen evolution. And the anodic process is depressed to a greater extent than the cathodic process. The synergistic mechanism of the composite inhinbitors proves to be the enhancement of adsorption of PEG600 by In（OH）3. Potentiostatic experiment results and SEM images verify the inhibition of dendritic growth by the composite inhibitors.展开更多
Fe-58at%Al alloy is undercooled up to 222 K (0.15TL) with the drop tube technique. It is found that there exists a critical undercooling about 185 K, beyond which a 揹endrite-equiaxed?growth morphology transition occu...Fe-58at%Al alloy is undercooled up to 222 K (0.15TL) with the drop tube technique. It is found that there exists a critical undercooling about 185 K, beyond which a 揹endrite-equiaxed?growth morphology transition occurs in FeAl intermetallic compound. This transition is character-ized by sharp decrease of its grain size. Once the undercool-ing exceeds 215 K, the peritectic transformation is sup-pressed completely and a fibrous structure is formed, which results from the cooperative growth of FeAl and FeAl2 com-pounds.展开更多
The stability range of primary spacing of the tilted dendritic arrays in directional solidification has been studied by quantitative phase-field simulations. Results show that both the real growth direction and morpho...The stability range of primary spacing of the tilted dendritic arrays in directional solidification has been studied by quantitative phase-field simulations. Results show that both the real growth direction and morphological shapes of dendritic arrays change with the primary spacing for different misorientation angles(θ0). It has been found that the lower limit of primary spacing is independent of θ0, but the upper limit of primary spacing is strongly influenced by that. The two kinds of tertiary branching instabilities result in different behaviors of the variation of the upper limit with misorientation angle for different pulling velocities.展开更多
Electromagnetic levitation technique was used to undercool bulk samples of Co-20% Cu and Co-60% Cu alloys and high undercoolings up to 303 and 110 K were achieved,respectively.The dendritic growth velocities were meas...Electromagnetic levitation technique was used to undercool bulk samples of Co-20% Cu and Co-60% Cu alloys and high undercoolings up to 303 and 110 K were achieved,respectively.The dendritic growth velocities were measured as a function of undercooling.The dendrite growth velocity of the Co-20% Cu alloy was much higher than that of the Co-60% Cu alloy.The experimental data were analyzed on the basis of the LKT/BCT dendritic growth model by taking into account non-equilibrium interface kinetics.It has been revealed that a transition from solute diffusion controlled dendritic growth to thermal diffusion controlled dendritic growth occurs at an undercooling of about 66 K for the Co-20% Cu alloy,whereas the dendrite growth in Co-60% Cu alloy proceeds in a solute diffusion controlled mode within a large solidification temperature range,and the solutal undercooling plays a dominant role.It is thus deduced that certain distinct solidification temperature ranges may be responsible for the different solidification modes for the two alloys.展开更多
文摘The corrosion inhibition property of PEG600 and In（OH）3 as composite corrosion inhibitors for （second-）（ary） alkaline zinc electrodes was studied, and the inhibition efficiency was determined as 81.9%. The research focused on the mechanism by the methods of electrochemical impedance spectroscopy, polarization curves and IR spectroscopy. The results indicate that the corrosion inhibition effectiveness is attributed to the joint inhibition of anodic zinc dissolution and cathodic hydrogen evolution. And the anodic process is depressed to a greater extent than the cathodic process. The synergistic mechanism of the composite inhinbitors proves to be the enhancement of adsorption of PEG600 by In（OH）3. Potentiostatic experiment results and SEM images verify the inhibition of dendritic growth by the composite inhibitors.
文摘Fe-58at%Al alloy is undercooled up to 222 K (0.15TL) with the drop tube technique. It is found that there exists a critical undercooling about 185 K, beyond which a 揹endrite-equiaxed?growth morphology transition occurs in FeAl intermetallic compound. This transition is character-ized by sharp decrease of its grain size. Once the undercool-ing exceeds 215 K, the peritectic transformation is sup-pressed completely and a fibrous structure is formed, which results from the cooperative growth of FeAl and FeAl2 com-pounds.
基金supported by the National Natural Science Foundation of China(Grant Nos.61078057 and 51172183)the Natural Science Foundation of Shaanxi Province in China(Grant No.2012JQ8013)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.3102014KYJD026 and JC20120246)the grant from the Program of New Staff and Research Area Project of NPU(Grant No.13GH014602)
文摘The stability range of primary spacing of the tilted dendritic arrays in directional solidification has been studied by quantitative phase-field simulations. Results show that both the real growth direction and morphological shapes of dendritic arrays change with the primary spacing for different misorientation angles(θ0). It has been found that the lower limit of primary spacing is independent of θ0, but the upper limit of primary spacing is strongly influenced by that. The two kinds of tertiary branching instabilities result in different behaviors of the variation of the upper limit with misorientation angle for different pulling velocities.
基金supported by the National Natural Science Foundation of China (Grant No.50871088)NPU-FFR and the Foundation of Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials,Ministry of Education,Shandong University,China
文摘Electromagnetic levitation technique was used to undercool bulk samples of Co-20% Cu and Co-60% Cu alloys and high undercoolings up to 303 and 110 K were achieved,respectively.The dendritic growth velocities were measured as a function of undercooling.The dendrite growth velocity of the Co-20% Cu alloy was much higher than that of the Co-60% Cu alloy.The experimental data were analyzed on the basis of the LKT/BCT dendritic growth model by taking into account non-equilibrium interface kinetics.It has been revealed that a transition from solute diffusion controlled dendritic growth to thermal diffusion controlled dendritic growth occurs at an undercooling of about 66 K for the Co-20% Cu alloy,whereas the dendrite growth in Co-60% Cu alloy proceeds in a solute diffusion controlled mode within a large solidification temperature range,and the solutal undercooling plays a dominant role.It is thus deduced that certain distinct solidification temperature ranges may be responsible for the different solidification modes for the two alloys.
