查看更多>>摘要：It is of significance that the wettability between the molten alloy and the Al2O3 affects the inclusion removal,nozzle clogging and refractory erosion.In the present work,the wettability between the Al2O3 substrate and Fe-P-Ti alloys with different Ti content was investigated by using the sessile droplets method.The interfacial characteristics were investigated by scanning electron microscope(SEM).The contact angles between the sintered Al2O3 substrate and Fe-P-Ti alloys with 0,0.05,0.10 and 0.15 wt％Ti are 100.1°,97.3°,94.5° and 90.5°,respectively.The oxidation of[Al]and[Ti]in the molten alloys leads to the formation of the oxides on the droplets.With the increase of Ti content in the Fe-P-Ti alloys,the formed oxides change from Al2O3 to Ti-containing oxides.The reaction between[Ti]and Al2O3 substrate in the interface results in the formation of Ti-containing oxides.The quantity of the interfacial oxides increases with the increase of Ti content in the alloys.As a result,the synergetic effect of the formation of the interfacial products and the oxides on the surface of droplets leads to the decrease of the contact angles between the Al2O3 substrate and Fe-P-Ti alloys due to the increase of Ti content.
查看更多>>摘要：The carbides and pores play a critical role in the cracking tendencies of nickel-based single-crystal superalloys during deformation.In the present study,the deformation mechanism and local strain evolution behavior around carbides and pores were studied through in-situ tensile deformation experiments.The findings indicate that multiple slip systems are easily activated during tensile deformation in single-crystal alloys.Furthermore,the strain localization in carbides is influenced by their morphology,with rod-like and flake-like carbides demon-strating an increased likelihood of cracking during deformation.The strain localization adjacent to pores is markedly more intense,rendering these areas particularly susceptible to cracking.Our work therefore offers a theoretical foundation for enhancing the mechanical properties of nickel-based single-crystal superalloys by controlling carbide morphology and pore formation.
查看更多>>摘要：The ultra-high nickel-layered cathodes(Ni ≥ 90％)has garnered significant attention due to its high specific capacity.However,the widespread application of ultra-high nickel-layered cathodes still suffers limitation by structural instability and poor rate performance.Herein,a crystal-face-induced strategy is proposed to enhance rate and cycling performances of the electrode by constructing rapid Li+diffusion channel and reducing internal grain boundaries of secondary particles.The crystal-face-induced strategy facilitates the growth of {010} lattice plane.Highly exposed {010} planes provide wide-open and unobstructed channels for Li+deintercalation/intercalation,enhances the electrode diffusion kinetics,and thus improves the electrode rate performance.In addition,this strategy promotes the primary particle growth,reduces the grain boundaries of secondary particles and mitigates the electrode/electrolyte interface side reactions,enhancing the structural stability and cycling life of the electrode.Accordingly,the modified sample achieved a reversible specific capacity of 198.3 mAh g-1 at 1 C(1 C=180 mA g-1)and maintained a capacity retention rate of 88.5％after 100 cycles,higher than that of the original sample(73.6％,146 mAh g-1).At the high rate of 5 C,it can maintain a high specific capacity of 178 mAh g-1(capacity retention rate of 99％)after 150 cycles.This work is a leap in ultra-high nickel-layered cathodes development and provides insights into the design of electrode materials for other batteries.
查看更多>>摘要：Interface modification of zinc(Zn)metal anode with conductive three-dimensional(3D)structure is widely uti-lized in zinc ion batteries.However,the uniformity of zinc nucleation on surface microstructure is rarely investigated which exacerbates the tip effect and raises unstable risk.Herein,a strategy via the initial copper(Cu)alloying and following sulfurization treatment is reported to accomplish boosted uniform nucleation of zinc on the modified layer with dense microstructures.This epitaxial sulfide phase not only improves the wetting area to revitalize the microstructural surface,but also forms a bifunctional zincophilic Cu2S/CuZn alloy interface layer,which combines the merits of guided local ions diffusion and improved zinc nucleation environment.As a result,a homogeneous growth of zinc on the 3D structural substrate can be realized,and cycling stability of the achieved Cu2S/CuZn electrode with a practical capacity of 1 mAh cm-2 under 1 mA cm-2 or amplified current density of 10 mA cm-2 is significantly enhanced.This work provides an epitaxial strategy in constructing a bifunctional zincophilic interface layer for boosting zinc nucleation,and offers a new perspective on the modification of 3D surface structure for stabilization of zinc anode.
查看更多>>摘要：This article investigates the evolution and control of inclusions in the smelting process of titanium containing ultra-low carbon steel.Through industrial experiments,the influence of oxygen content before aluminum addition on inclusions in ultra-low carbon IF steel was explored,and the evolution process of inclusions was studied.The microstructure of different types of inclusions was observed using three-dimensional analysis techniques.Research has found that the oxygen content before aluminum addition has no significant effect on the final ox-ygen content.However,under low aluminum and low oxygen conditions,the size of inclusions formed is small and difficult to float and remove.Even if the cycle time is extended,the AF index of inclusions remains at a high level.Through three-dimensional morphology analysis of inclusions,it was found that alumina formed under high aluminum and high oxygen conditions is very dense,while inclusions are relatively loose under low aluminum and low oxygen conditions.In addition,through the analysis of aluminum oxygen supersaturation before the formation of aluminum oxide inclusions,it was found that due to the low oxygen content,the nucleation rate of aluminum oxide in the early stage of inclusion formation is relatively low,and the inclusions grow along the trajectory of oxygen,ultimately forming polycrystalline aluminum oxide inclusions.This article also observed for the first time the initial three-dimensional morphology of Al Ti inclusions,providing a theoretical basis for further optimizing smelting processes and controlling inclusions.
查看更多>>摘要：A tri-layered(B-G-B)dielectric films were simply prepared by alternatively spin-coating boron nitride/poly-methylmethacrylate(BN/PMMA,B)and graphene nanosheets(GNS/PMMA,G)compound solutions.The struc-ture,morphology,thermal conductivity,and particularly the dielectric and relaxation behaviors were systematically studied.Results showed that a good exfoliation and dispersion of BN and GNS can be simply achieved through intensive mechanical compounding with PMMA in the internal mixer.The dielectric constant and breakdown strength of the obtained 1-3-1(B-G-B)sandwich composite film reached 4.3(@1 kHz)and 458.6 kV/mm,being 119％and 113％higher than that of pure PMMA,respectively.Furthermore,the overall thermal conductivity of sandwich 1-3-1 composite increased by 112％due to the addition of thermally conductive BN and GNS.The sandwich design strategy provided an effective way of achieving good permittivity,high insulation,and improved thermal conductivity simultaneously,showing potential applications in the miniaturization and inte-gration of electronic devices.
查看更多>>摘要：The study on the uniformity of electrical performance of large wafer-scale Hf0.5Zr0.5O2(HZO)ferroelectric ca-pacitors is still lacking yet now.In this work,TiN/HZO/TiN metal-ferroelectric-metal(MFM)devices on 12-inch silicon wafers have been fabricated by thermal atomic layer deposition.The correlation of thickness uniformity with device-to-device variation of electrical properties and yield of the 12-inch MFM system was investigated.It was found that the uniformity of ferroelectric properties is closely related to the variation of HZO thickness of the MFM system,the concentration of oxygen vacancies in the micro-region of the HZO film,and the ferroelectric phase micro-distribution on 12-inch Si wafer.This work provides some important information for the perfor-mance optimization of HfO2-based ferroelectric random access memories.
Muhammad Zubair KhanAmjad HussainSeung-Bok LeeTak-Hyoung Lim...
606-613页
查看更多>>摘要：In the present study,the operational lifetime of a solid oxide fuel(SOFC)short stack is predicted by investigating the performance degradation of both the short stack and its cells throughout 1000 h at 800 ℃.The short stack and integral cell voltages are continuously measured during the long-term test,with electrochemical impedance spectroscopy(EIS)conducted every 200 h.The short stack voltage decreased rapidly for the initial 200-300 h and afterwards,it decreased at a slow rate due to the increase in the Ohmic and polarization resistances in the same manner.Scanning electron microscopy results show that there is no delamination or cracking among constituent layers of the short-stack cells.The single degradation effects of the Ni coarsening in the anode,cation migration and surface segregation in cathode and oxide scale growth in metallic interconnect mesh are successfully inte-grated into a comprehensive lifetime prediction model.The experimentally measured voltage degradation data of the short stack fits well with the developed mathematical model and allows the successful prediction of the lifetime up to 50,000 h.
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