Ti-1100 alloys were melted in a controlled atmospheric induction furnace equipped with a Ca O crucible. The microstructure, chemical composition, microhardness and metal-crucible interfacial reactions were systematica...Ti-1100 alloys were melted in a controlled atmospheric induction furnace equipped with a Ca O crucible. The microstructure, chemical composition, microhardness and metal-crucible interfacial reactions were systematically investigated. The results demonstrate that the primary solidification microstructure in the as-cast alloys was the typical Widmansttten structure. The interactions between crucible and molten alloys are attributed to slight chemical dissolution and weak physical erosion. According to the line scanning analysis, the interfacial layer（α-case） thicknesses of Ti-1100 samples in the bottom and side wall are about 18 and 17 μm, respectively, which are slightly lower than those presented from microhardness tests（25 and 20 μm）. The formation of α-case was caused by interstitial oxygen atoms. The standard Gibbs energy of reaction Ca O（s）=Ca＋O for Ti-1100 alloy was also determined. The equilibrium constant and the interaction parameter between calcium and oxygen were obtained as lg K=-3.14 and eCa O =-3.54.展开更多
The interfacial reactions of chalcopyrite in ammonia–ammonium chloride solution were investigated.The chalcopyrite surface was examined by scanning electron microscopy and X-ray photoelectron spectroscopy(XPS)techniq...The interfacial reactions of chalcopyrite in ammonia–ammonium chloride solution were investigated.The chalcopyrite surface was examined by scanning electron microscopy and X-ray photoelectron spectroscopy(XPS)techniques.It was found that interfacial passivation layers of chalcopyrite were formed from an iron oxide layer on top of a copper sulfide layer overlaying the bulk chalcopyrite,whereas CuFe1-xS2 or copper sulfides were formed via the preferential dissolution of Fe.The copper sulfide layer formed a new passivation layer,whereas the iron oxide layer peeled off spontaneously and partially from the chalcopyrite surface.The state of the copper sulfide layer was discussed after being deduced from the appearance of S2-,S22-,Sn2-,S0 and SO42-.A mechanism for the oxidation and passivation of chalcopyrite under different pH values and redox potentials was proposed.Accordingly,a model of the interfacial reaction on the chalcopyrite surface was constructed using a three-step reaction pathway,which demonstrated the formation and transformation of passivation layers under the present experimental conditions.展开更多
For aqueous interfacial reactions involving H+and OH-, the interfacial pH varies dynamically during the reaction process, which is a key factor determining the reaction performance. Herein, the kinetic relevance betwe...For aqueous interfacial reactions involving H+and OH-, the interfacial pH varies dynamically during the reaction process, which is a key factor determining the reaction performance. Herein, the kinetic relevance between the interfacial pH and reaction rate is deciphered owing to the success in establishing the transport equations of H+/OH- in unbuffered solutions, and is charted as a current(j)–pH diagram in the form of an electrochemical response. The as-described j–pH interplay is experimentally verified by the oxygen reduction and hydrogen evolution reactions. This diagram serves to form a panoramic graphic view of pH function working on the interfacial reactions in conjunction with the Pourbaix’s potential–pH diagram, and particularly enables a kinetic understanding of the transport effect of H+and OH-on the reaction rate and valuable instruction toward associated pH control and buffering manipulation.展开更多
A novel Sn-2.5Ag-2.0Ni alloy was used for soldering SiCp/Al composites substrate deposited with electroless Ni(5%P) (mass fraction)and Ni(10%P)(mass fraction)layers.It is observed that variation of P contents in the e...A novel Sn-2.5Ag-2.0Ni alloy was used for soldering SiCp/Al composites substrate deposited with electroless Ni(5%P) (mass fraction)and Ni(10%P)(mass fraction)layers.It is observed that variation of P contents in the electroless Ni(P)layer results in different types of microstructures of SnAgNi/Ni(P)solder joint.The morphology of Ni3Sn4 intermetallic compounds(IMCs)formed between the solder and Ni(10%P)layer is observed to be needle-like and this shape provides high speed diffusion channels for Ni to diffuse into solder that culminates in high growth rate of Ni3Sn4.The diffusion of Ni into solder furthermore results in the formation of Kirkendall voids at the interface of Ni(P)layer and SiCp/Al composites substrate.It is observed that solder reliability is degraded by the formation of Ni2SnP,P rich Ni layer and Kirkendall voids.The compact Ni3Sn4 IMC layer in Ni(5%P)solder joint prevents Ni element from diffusing into solder,resulting in a low growth rate of Ni3Sn4 layer.Meanwhile,the formation of Ni2SnP that significantly affects the reliability of solder joints is suppressed by the low P content Ni(5%P)layer.Thus,shear strength of Ni(5%P) solder joint is concluded to be higher than that of Ni(10%P)solder joint.Growth of Ni3Sn4 IMC layer and formation of crack are accounted to be the major sources of the failure of Ni(5%P)solder joint.展开更多
The wettability and interfacial reactions of four kinds of PdNi-based brazing fillers on C-C composite were studied with the sessile drop method.The results showed that the wettability of these brazing fillers was imp...The wettability and interfacial reactions of four kinds of PdNi-based brazing fillers on C-C composite were studied with the sessile drop method.The results showed that the wettability of these brazing fillers was improved with the increase of Cr content. Cr distributed at the interface of brazing filler/C-C composite and the formation of Cr23C6 phase was speculated.In the interface between Ni-33Cr-24Pd-4Si brazing filler and C-C composite,element Cr reacted with C-C to form Cr-C reaction layer.Pd together with Si participated in the interfacial reactions and formed Pd2Si and Pd3Si phases.Furthermore,in this reaction zone,the residual brazing alloy became Ni-rich and Pd-depleted.展开更多
The internal flow,free surface shape,and level fluctuation of liquid metal exposed to linear electromagnetic stirring were measured and analyzed against the background of an actual metallurgical equipment with linear ...The internal flow,free surface shape,and level fluctuation of liquid metal exposed to linear electromagnetic stirring were measured and analyzed against the background of an actual metallurgical equipment with linear electromagnetic stirring system.The desulphurization process,with or without imposition of linear electromagnetic stirring,was also studied experimentally.The changes in sulfur content of hot metal with respect to time were obtained,and the volumetric mass transfer coefficients corresponding to different stirring currents were determined.The results showed that linear electromagnetic stirring can effectively promote internal flow,effectively increase the level fluctuation,and significantly improve the kinetic condition of liquid metal.The internal flow and level fluctuation of liquid metal increase in line with the increase in electromagnetic stirring intensity.The desulphurization experiments show that linear electromagnetic stirring can significantly promote the desulphurization process of hot metal,and that the technology has wide application potential in promoting various slag-metal reactions.展开更多
Twin-roll casting has been recently revealed to be an effi cient technique to produce rejuvenated metallic glass(MG)strips.Due to the high melting point and high hardness,pure Mo is considered as a good roller materia...Twin-roll casting has been recently revealed to be an effi cient technique to produce rejuvenated metallic glass(MG)strips.Due to the high melting point and high hardness,pure Mo is considered as a good roller material as pure Cu.However,the wettability and interfacial reactions between MG melts and Cu or Mo remain largely unknown.In this work,a series of sessile droplet wetting experiments are designed to investigate the wettability and reactions between Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)(Vit.1)or(Zr 0.401 Ti_(0.133)Cu_(0.118)Ni_(0.101)Be_(0.247))_(99)Nb_(1)(Nb1)MG melts and Cu/Mo substrates at temperatures of 1073,1123 and 1173 K.It is found that the wettability and interfacial reactions of the Vit.1 and Nb1 MG melts on the Cu substrates are very similar.The equilibrium contact angles are~30°at 1073 K and~25°-27°at 1123 K.The MG melts completely spread out on the Cu substrates at 1173 K.Cu substrates are slightly dissolved in the MG melts event at 1073 K,and a transitional reaction layer exists between the droplet and the Cu substrate.In comparison,the Vit.1 MG melt exhibits a much improved wettability on the Mo substrate.The equilibrium contact angle of the Vit.1/Mo is only 6°at 1073 K and 5°at 1123 K.No signifi cant diff usion of Mo into the droplet occurs even at 1173 K with a holding time of~30 min.The interfaces of the Vit.1/Mo samples are sharp,and no interfacial reaction layers form.These fi ndings indicate that pure Mo can be a good roller material for twin-roll casting at high temperatures,and the Mo-made rollers are expected of capability to produce MG strips with good quality.展开更多
The wetting property of （Sn-9Zn）-2Cu （wt pct） on Ni substrate and the evolution of interracial microstructure in （Sn-9Zn）-2Cu/Ni joints during soldering as well as isothermal aging were studied. The wetting abil...The wetting property of （Sn-9Zn）-2Cu （wt pct） on Ni substrate and the evolution of interracial microstructure in （Sn-9Zn）-2Cu/Ni joints during soldering as well as isothermal aging were studied. The wetting ability of eutectic Sn-gZn solder on Ni substrate was markedly improved by adding 2 wt pct Cu into this solder alloy. Plate-like Cu5Zn8 intermetallic compounds （IMCs） were detected in （Sn-9Zn）-2Cu solder matrix. A continuous NisZn21 IMC layer was formed at （Sn-9Zn）-2Cu/Ni interface after soldering. This IMC layer kept its type and integrality even after aging at 170℃ for up to 1000 h. At the early aging stage （before 500 h）, the IMC layer grew fast and its thickness followed a linear relationship with the square root of aging time. Thereafter, however, the thickness increased very slowly with longer aging time. When the joints were aged for 1000 h, a new IMC phase, （Cu,Ni）5Zn8, was found in the matrix near the interface. The formation of （Cu,Ni）5Zns phase can be attributed to the diffusion of Ni atoms into the solder matrix from the substrate.展开更多
Diffusion couple experiments were performed to study the thermodynamic and kinetic mechanisms of interfacial reactions between the 316L stainless steel and the composite MnO-SiO_(2) oxide during isothermal heating at ...Diffusion couple experiments were performed to study the thermodynamic and kinetic mechanisms of interfacial reactions between the 316L stainless steel and the composite MnO-SiO_(2) oxide during isothermal heating at 1473 K(1200℃)for 1,3,5,and 10 h and at 1173,1273,1373,1473,and 1573 K(900,1000,1100,1200,and 1300℃)for 3 h.Compositional variations in the 316L stainless steel and the composite MnO-SiO_(2) oxide in the vicinity of the steel-oxide interface in each diffusion couple specimen were determined.Before and after isothermal heating,thermodynamic equilibria between the oxide and steel at the interface were estimated in accordance with the calculation of the Gibbs free energy change in the interfacial steel-oxide reactions.The diffusion coefficients of Mn,Cr,and Si in 316L stainless steel under different experimental conditions were quantitatively acquired.The results showed that solid-state interfacial reactions occurred between the Cr in the 316L stainless steel and composite MnO-SiO_(2) oxide during isothermal heating,which resulted in the depletion of Cr and accumulation of Si and Mn in the steel in the vicinity of the steel-oxide interface.The widths of the Crdepleted zone,Mn-accumulated zone and Si-accumulated zone all showed increasing trends with increasing isothermal heating temperature and time.The average values of the diffusion coefficients of Mn,Cr,and Si in the steel at 1473 K(1200℃)were 1.21×10^(^(-14))±2.96×10^(-15),1.69×10^(-14)±2.54×10^(-15),and 1.00×10^(-14)±1.96×10^(-15) m^(2)s^(-1),respectively,and they continued to increase with increasing isothermal heating temperature.展开更多
The interfacial reaction between Ti-6Al-4V alloy and ZrO2 ceramic mold with zirconia sol binder was investigated by keeping the 12 g alloy melt in a vacuum induction furnace for 15 s.The microstructures,element distri...The interfacial reaction between Ti-6Al-4V alloy and ZrO2 ceramic mold with zirconia sol binder was investigated by keeping the 12 g alloy melt in a vacuum induction furnace for 15 s.The microstructures,element distribution and phase constitution of the interface were identified by optical microscopy(OM),scanning electron microscopy(SEM)equipped with energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD).The results show that the whole interface reaction layer can be divided into three regions:metal penetration layer,transition layer,and hardened layer according to the structure morphology,which has the characteristics of severe metal penetration,finer lamellar,and coarse oxygen-richαphase,respectively.The erosion of the alloy melt on the ceramic mold promotes the decomposition of zirconia,which leads to the increase of local Zr concentration,greatly increasing the activity coefficient of Ti,aggravating the occurrence of interfacial reaction.Thus,the interfacial reaction shows the characteristics of chain reaction.When the oxygen released by the dissolution of zirconia exceeds the local solid solubility,it precipitates in the form of bubbles,resulting in blowholes at the interface.The result also indicates that the zirconia mold with zirconia sol binder is not suitable for pouring heavy titanium alloy castings.展开更多
Li-rich oxides are considered as promising candidate cathode materials for high-energy Li-ion batteries due to their high specific capacity.However,the widespread adoption of Li-rich materials is hindered because of t...Li-rich oxides are considered as promising candidate cathode materials for high-energy Li-ion batteries due to their high specific capacity.However,the widespread adoption of Li-rich materials is hindered because of the lack of a stable surface structure to inhibit interfacial side reactions.In this study,a stable LiF@spinel dual shell was constructed on the surface of Li-rich materials,in which spinel is formed by in situ surface recon-struction,and LiF is bonded to the spinel through the Ni–F bond.The spinel serves as a buffer layer between the LiF coating and the Li-rich oxide,providing a three-dimensional Li-ion diffusion channel to improve the Li-ion diffusion coefficient,while the outer LiF plays a critical role in isolating the cathode from the electrolyte.Under the abovementioned dual effect,the interfacial side reactions of Li-rich materials are inhibited,thereby improving their cycle stability.The obtained LiF@spinel-coated Li-rich cathode exhibits an enhanced capacity retention of 81.5%after 150 cycles at a current density of 2 C,which is better than the pristine Li-rich sample(63.2%).These findings indicate that the construction of the LiF@spinel dual shell is a successful strategy for the modification of Li-rich materials.展开更多
The preparation and functionalization of polymeric capsules attract intense attention due to their application in various areas.Herein we presented an amphiphilic alternating copolymer(ACP)-based microcapsule which is...The preparation and functionalization of polymeric capsules attract intense attention due to their application in various areas.Herein we presented an amphiphilic alternating copolymer(ACP)-based microcapsule which is both robust and readily-functionalized through interfacial click polymerization.A water-in-oil emulsion was constructed to act as the reaction medium,the hydrophilic 1,3-butadiene diepoxide(BDE)in water phase reacted with the oleophilic 1,4-dibutanedithiol(BDT)in oil phase at the water-oil interface to form the amphiphilic ACP named poly(2,3-dihydroxy butylene-alt-butylene dithioether)(abbreviated as P(DHB-a-BDT)below),which would deposite in situ to form the micro-sized capsules.Significantly,the dried capsules are robust enough to be rehydrated once the water was added and almost restored their original morphologies.Further elucidation showed that the Young's modulus of these capsules exceeded 1 GPa.As long as we know,it is the first time for the mechanical properties of the ACP-based microstructures being investigated.Besides,functionalization could be achieved simultaneously with the formation process.As a proof of concept,positive-charged capsules were successfully obtained through click copolymerization.Stemming from the unique characteristics of amphiphilic ACPs which combined both merits of click chemistry and interfacial reactions,all these features of the current method as well as the resultant capsules may promote the application of the polymeric capsules.展开更多
Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,a...Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.展开更多
The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals（·OH）from reactions between recyclable solid catalysts and H2O2 at acidic or even circumneutral pH.Hence,it can effectively oxidiz...The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals（·OH）from reactions between recyclable solid catalysts and H2O2 at acidic or even circumneutral pH.Hence,it can effectively oxidize refractory organics in water or soils and has become a promising environmentally friendly treatment technology.Due to the complex reaction system,the mechanism behind heterogeneous Fenton reactions remains unresolved but fascinating,and is crucial for understanding Fenton chemistry and the development and application of efficient heterogeneous Fenton technologies.Iron-based materials usually possess high catalytic activity,low cost,negligible toxicity and easy recovery,and are a superior type of heterogeneous Fenton catalysts.Therefore,this article reviews the fundamental but important interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials..OH,hydroperoxyl radicals/superoxide anions（HO2./O2^-.）and high-valent iron are the three main types of reactive oxygen species（ROS）,with different oxidation reactivity and selectivity.Based on the mechanisms of ROS generation,the interfacial mechanisms of heterogeneous Fenton systems can be classified as the homogeneous Fenton mechanism induced by surface-leached iron,the heterogeneous catalysis mechanism,and the heterogeneous reaction-induced homogeneous mechanism.Different heterogeneous Fenton systems catalyzed by characteristic iron-based materials are comprehensively reviewed.Finally,related future research directions are also suggested.展开更多
Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface,predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution.Particularly,the ...Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface,predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution.Particularly,the intricate mechanisms behind the electrochemical discrepancies induced by interfacial Zn^(2+)-solvation and deposition behavior demand comprehensive investigation.Organic molecules endowed with special functional groups (such as hydroxyl,carboxyl,etc.) have the potential to significantly optimize the solvation structure of Zn^(2+)and regulate the interfacial electric double layer (EDL).By increasing nucleation overpotential and decreasing interfacial free energy,these functional groups facilitate a lower critical nucleation radius,thereby forming an asymptotic nucleation model to promote uniform Zn deposition.Herein,this study presents a pioneering approach by introducing trace amounts of n-butanol as solvation regulators to engineer the homogenized Zn (H-Zn) anode with a uniform and dense structure.The interfacial reaction and structure evolution are explored by in/ex-situ experimental techniques,indicating that the H-Zn anode exhibits dendrite-free growth,no by-products,and weak hydrogen evolution,in sharp contrast to the bare Zn.Consequently,the H-Zn anode achieves a remarkable Zn utilization rate of approximately 20% and simultaneously sustains a prolonged cycle life exceeding 500 h.Moreover,the H-Zn//NH_(4)V_(4)O^(10)(NVO) full battery showcases exceptional cycle stability,retaining 95.04%capacity retention after 400 cycles at a large current density of 5 A g^(-1).This study enlightens solvation-regulated additives to develop Zn anode with superior utilization efficiency and extended operational lifespan.展开更多
To elucidate the formation mechanisms of burn-on sand and metal penetration during sand casting,some laboratory experiments were carried out at different temperatures(1813,1833,1853,and 1873 K)and holding time(20,40,6...To elucidate the formation mechanisms of burn-on sand and metal penetration during sand casting,some laboratory experiments were carried out at different temperatures(1813,1833,1853,and 1873 K)and holding time(20,40,60,and 90 min)to simulate the interaction between ZG13Cr9Mo1VNbN stainless steel and chromite sand.The results demonstrate that the defects primarily consist of a mixture of the liquid phase,chromite,and metal.The main components of the liquid phase are SiO_(2),MnO,MgO,Cr_(2)O_(3),FeO,and Al_(2)O_(3),and the formation of Cr_(2)O_(3)through interfacial redox reactions has been discovered.The presence of a liquid phase plays a pivotal role in influencing burn-on sand and metal penetration.Interface reactions are prioritized,with burn-on sand maintaining a predominant influence.As the liquid phase quantity within the sand escalates,there is a corresponding incremental rise in the incidence of metal penetration.Even a minimal presence of the silicon element in steel can impact the liquid phase’s formation.Moreover,the decomposition or dissolution of chromite sand is a significant factor in the development of burn-on sand and metal penetration.Thus,a thorough investigation into the conditions and contributing factors of this phenomenon is essential for its effective management and mitigation.展开更多
Uncontrolled dendrite growth,sluggish reaction kinetics,and drastic side reactions on the anodeelectrolyte interface are the main obstacles that restrict the application prospect of aqueous zinc-ion batteries.Traditio...Uncontrolled dendrite growth,sluggish reaction kinetics,and drastic side reactions on the anodeelectrolyte interface are the main obstacles that restrict the application prospect of aqueous zinc-ion batteries.Traditional glass fiber(GF)separator with chemical inertness is almost ineffective in restricting these challenges.Herein,inspired by the ionic enrichment behavior of seaweed plants,a facile biomass species,anionic sodium alginate(SA),is purposely decorated on the commercial GF separator to tackle these issues towards Zn anode.Benefiting from the abundant zincophilic functional groups and superior mechanical strength properties,the as-obtained SA@GF separator could act as ion pump to boost the Zn^(2+)transference number(0.68),reduce the de-solvation energy barrier of hydrated Zn^(2+),and eliminate the undesired concentration polarization effect,which are verified by experimental tests,theoretical calculations,and finite element simulation,respectively.Based on these efficient modulation mechanisms,the SA@GF separator can synchronously achieve well-aligned Zn deposition and the suppression of parasitic side-reactions.Therefore,the Zn‖Zn coin cell integrated with SA@GF separator could yield a prolonged calendar lifespan over 1230 h(1 mA cm^(-2)and 1 mAh cm^(-2)),exhibiting favorable competitiveness with previously reported separator modification strategies.Impressively,the Zn-MnO_(2)full and pouch cell assembled with the SA@GF separator also delivered superior cycling stability and rate performance,further verifying its practical application effect.This work provides a new design philosophy to stabilize the Zn anode from the aspect of separator.展开更多
In the field of particle reinforced magnesium(Mg)matrix composites(MMCs),the interfacial microstructures between reinforcements and Mg matrix are a subject of interest for most researchers.In this work,the 2 wt.%Ti pa...In the field of particle reinforced magnesium(Mg)matrix composites(MMCs),the interfacial microstructures between reinforcements and Mg matrix are a subject of interest for most researchers.In this work,the 2 wt.%Ti particle reinforced Mg-6Zn alloy composites with different contents(0,0.5,1,1.5,2 wt.%)of Mn were prepared using semi-solid stirring assisted ultrasonic treatment followed by hot extrusion.With the increment of Mn element,the characteristics of mixed-grain structure became obvious and the DRX was inhibited.Meanwhile,the interfacial product gradually changed from MgZn_(2)to Mn_(2)Ti.The tensile test demonstrated that the 2Ti/Mg-6Zn-1.5Mn composite exhibited an excellent strength-ductility synergy,achieving the highest yield stress(YS),ultimate tensile stress(UTS)of 239 MPa,366 MPa,respectively,along with a notable elongation(El.)of 20.6%.The increased strength is mainly due to the grain refinement,the precipitation strengthening,the HDI strengthening and the strong interfacial bonding including the tightly Ti/Mn_(2)Ti bonding and the Mn_(2)Ti/Mg coherent orientation relationship.The ideal El.is the result of fine/coarse bimodal structure and the proper interfacial reaction,which can reduce the occurrence of cracks.展开更多
Even though vacuum induction melting(VIM)is widely employed in the industrial production of bulk metallic glasses(BMGs),the effect and mechanism of the interfacial reaction between the melt and the oxide ceramic cruci...Even though vacuum induction melting(VIM)is widely employed in the industrial production of bulk metallic glasses(BMGs),the effect and mechanism of the interfacial reaction between the melt and the oxide ceramic crucible on BMG formations are not yet fully understood.Here,the influences and mechanisms of the interfacial reaction on a Zr-based BMG(Vit 105)subjected to various melting temperatures and holding times are revealed by employing experiments and theoretical calculations.We find that the degree of interfacial reaction is intriguingly correlated with the process parameters during VIM processing,leading to an increase in the oxygen content of the alloy and the reaction layer thickness.Besides,the increase of oxygen content also induces variations in the ordering and shear transformation zone(STZ)size of the BMGs,thus resulting in the precipitation of a nanoscale fcc phase and affecting the mechanical properties and reliability under deformation of the alloy.Furthermore,thermodynamic and kinetic parameters involved in the interfacial reaction,such as the molar Gibbs free energy of each element,the apparent activation energy,etc.,are obtained,providing a comprehensive understanding of the transport processes at play.Our findings provide new insights into the preparation of BMGs by VIM and may be expanded to other melting techniques to accelerate the commercial application of metallic glasses.展开更多
development of refractories with low reactivity to rare earth inclusions is an important direction to solve the problem of the nozzle clogging of rare earth steel.La_(2)Ce_(2)O_(7),La_(2)Zr_(2)O_(7),and LaAlO_(3)powde...development of refractories with low reactivity to rare earth inclusions is an important direction to solve the problem of the nozzle clogging of rare earth steel.La_(2)Ce_(2)O_(7),La_(2)Zr_(2)O_(7),and LaAlO_(3)powders were synthesized using the high-temperature solid-state method with La_(2)O_(3),CeO_(2),ZrO_(2),and Al2O_(3)(particle sizes of 5-10μm)as raw materials,firing at 1400℃for 2 h.Subsequently,La_(2)Ce_(2)O_(7),La_(2)Zr_(2)O_(7),and Y_(2)O_(3)powders were pressed intoφ30 mm×7 mm substrate samples with PVA as a binder;and equal amounts of La_(2)O_(3),La_(2)S_(3),and LaAlO_(3)powders were placed on their surfaces.The samples were then fired at 1550℃for 3 h with carbon embedded.The interfacial reaction of the three rare earth oxide refractories(La_(2)Ce_(2)O_(7),La_(2)Zr_(2)O_(7),and Y_(2)O_(3))with the main rare earth inclusions(La_(2)O_(3),La_(2)S_(3),and LaAlO_(3))in molten rare earth steel was studied.The results show that the La_(2)Ce_(2)O_(7)sample has poor structural stability and readily reacts with La_(2)S_(3),leading to cracking.The La_(2)Zr_(2)O_(7)sample reacts with La_(2)O_(3)and LaAlO_(3)weakly,but performs poor La_(2)S_(3)corrosion resistance.The Y_(2)O_(3)sample demonstrates the weakest interaction with the three rare earth inclusions as well as the most stable structure,indicating significant potential as a specialized anti-clogging lining material for rare earth steel.展开更多
基金Projects(51001041,51171054)supported by the National Natural Science Foundation of China
文摘Ti-1100 alloys were melted in a controlled atmospheric induction furnace equipped with a Ca O crucible. The microstructure, chemical composition, microhardness and metal-crucible interfacial reactions were systematically investigated. The results demonstrate that the primary solidification microstructure in the as-cast alloys was the typical Widmansttten structure. The interactions between crucible and molten alloys are attributed to slight chemical dissolution and weak physical erosion. According to the line scanning analysis, the interfacial layer（α-case） thicknesses of Ti-1100 samples in the bottom and side wall are about 18 and 17 μm, respectively, which are slightly lower than those presented from microhardness tests（25 and 20 μm）. The formation of α-case was caused by interstitial oxygen atoms. The standard Gibbs energy of reaction Ca O（s）=Ca＋O for Ti-1100 alloy was also determined. The equilibrium constant and the interaction parameter between calcium and oxygen were obtained as lg K=-3.14 and eCa O =-3.54.
基金Project(2014CB643405)supported by the National Basic Research Program of China
文摘The interfacial reactions of chalcopyrite in ammonia–ammonium chloride solution were investigated.The chalcopyrite surface was examined by scanning electron microscopy and X-ray photoelectron spectroscopy(XPS)techniques.It was found that interfacial passivation layers of chalcopyrite were formed from an iron oxide layer on top of a copper sulfide layer overlaying the bulk chalcopyrite,whereas CuFe1-xS2 or copper sulfides were formed via the preferential dissolution of Fe.The copper sulfide layer formed a new passivation layer,whereas the iron oxide layer peeled off spontaneously and partially from the chalcopyrite surface.The state of the copper sulfide layer was discussed after being deduced from the appearance of S2-,S22-,Sn2-,S0 and SO42-.A mechanism for the oxidation and passivation of chalcopyrite under different pH values and redox potentials was proposed.Accordingly,a model of the interfacial reaction on the chalcopyrite surface was constructed using a three-step reaction pathway,which demonstrated the formation and transformation of passivation layers under the present experimental conditions.
基金the National Natural Science Foundation of China(51525805,51727812,51808526)。
文摘For aqueous interfacial reactions involving H+and OH-, the interfacial pH varies dynamically during the reaction process, which is a key factor determining the reaction performance. Herein, the kinetic relevance between the interfacial pH and reaction rate is deciphered owing to the success in establishing the transport equations of H+/OH- in unbuffered solutions, and is charted as a current(j)–pH diagram in the form of an electrochemical response. The as-described j–pH interplay is experimentally verified by the oxygen reduction and hydrogen evolution reactions. This diagram serves to form a panoramic graphic view of pH function working on the interfacial reactions in conjunction with the Pourbaix’s potential–pH diagram, and particularly enables a kinetic understanding of the transport effect of H+and OH-on the reaction rate and valuable instruction toward associated pH control and buffering manipulation.
基金Projects(50274014, 50774005) supported by the National Natural Science Foundation of ChinaProject(2006CB605207) supported by the National Basic Research Program of China+1 种基金Project(2006AA03Z557) supported by the National High-tech Research and Development of ChinaProject(I2P407) supported by MOE Program for Changjiang Scholars
文摘A novel Sn-2.5Ag-2.0Ni alloy was used for soldering SiCp/Al composites substrate deposited with electroless Ni(5%P) (mass fraction)and Ni(10%P)(mass fraction)layers.It is observed that variation of P contents in the electroless Ni(P)layer results in different types of microstructures of SnAgNi/Ni(P)solder joint.The morphology of Ni3Sn4 intermetallic compounds(IMCs)formed between the solder and Ni(10%P)layer is observed to be needle-like and this shape provides high speed diffusion channels for Ni to diffuse into solder that culminates in high growth rate of Ni3Sn4.The diffusion of Ni into solder furthermore results in the formation of Kirkendall voids at the interface of Ni(P)layer and SiCp/Al composites substrate.It is observed that solder reliability is degraded by the formation of Ni2SnP,P rich Ni layer and Kirkendall voids.The compact Ni3Sn4 IMC layer in Ni(5%P)solder joint prevents Ni element from diffusing into solder,resulting in a low growth rate of Ni3Sn4 layer.Meanwhile,the formation of Ni2SnP that significantly affects the reliability of solder joints is suppressed by the low P content Ni(5%P)layer.Thus,shear strength of Ni(5%P) solder joint is concluded to be higher than that of Ni(10%P)solder joint.Growth of Ni3Sn4 IMC layer and formation of crack are accounted to be the major sources of the failure of Ni(5%P)solder joint.
基金Projects(59905022,50475160)supported by the National Natural Science Foundation of China
文摘The wettability and interfacial reactions of four kinds of PdNi-based brazing fillers on C-C composite were studied with the sessile drop method.The results showed that the wettability of these brazing fillers was improved with the increase of Cr content. Cr distributed at the interface of brazing filler/C-C composite and the formation of Cr23C6 phase was speculated.In the interface between Ni-33Cr-24Pd-4Si brazing filler and C-C composite,element Cr reacted with C-C to form Cr-C reaction layer.Pd together with Si participated in the interfacial reactions and formed Pd2Si and Pd3Si phases.Furthermore,in this reaction zone,the residual brazing alloy became Ni-rich and Pd-depleted.
基金Item Sponsored by National Natural Science Foundation of China(50302004,50674021)
文摘The internal flow,free surface shape,and level fluctuation of liquid metal exposed to linear electromagnetic stirring were measured and analyzed against the background of an actual metallurgical equipment with linear electromagnetic stirring system.The desulphurization process,with or without imposition of linear electromagnetic stirring,was also studied experimentally.The changes in sulfur content of hot metal with respect to time were obtained,and the volumetric mass transfer coefficients corresponding to different stirring currents were determined.The results showed that linear electromagnetic stirring can effectively promote internal flow,effectively increase the level fluctuation,and significantly improve the kinetic condition of liquid metal.The internal flow and level fluctuation of liquid metal increase in line with the increase in electromagnetic stirring intensity.The desulphurization experiments show that linear electromagnetic stirring can significantly promote the desulphurization process of hot metal,and that the technology has wide application potential in promoting various slag-metal reactions.
基金financially supported by the National Natural Science Foundation of China(Nos.51790484 and 52171164)the National Key Research and Development Program of China(No.2018YFB0703402)+3 种基金the Science and Technology on Transient Impact Laboratory(6142606192208)Liaoning Revitalization Talents Program(Nos.XLYC1802078 and XLYC1807062)the Chinese Academy of Sciences(No.ZDBS-LY-JSC023)the Youth Innovation Promotion Association CAS(No.2021188)。
文摘Twin-roll casting has been recently revealed to be an effi cient technique to produce rejuvenated metallic glass(MG)strips.Due to the high melting point and high hardness,pure Mo is considered as a good roller material as pure Cu.However,the wettability and interfacial reactions between MG melts and Cu or Mo remain largely unknown.In this work,a series of sessile droplet wetting experiments are designed to investigate the wettability and reactions between Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)(Vit.1)or(Zr 0.401 Ti_(0.133)Cu_(0.118)Ni_(0.101)Be_(0.247))_(99)Nb_(1)(Nb1)MG melts and Cu/Mo substrates at temperatures of 1073,1123 and 1173 K.It is found that the wettability and interfacial reactions of the Vit.1 and Nb1 MG melts on the Cu substrates are very similar.The equilibrium contact angles are~30°at 1073 K and~25°-27°at 1123 K.The MG melts completely spread out on the Cu substrates at 1173 K.Cu substrates are slightly dissolved in the MG melts event at 1073 K,and a transitional reaction layer exists between the droplet and the Cu substrate.In comparison,the Vit.1 MG melt exhibits a much improved wettability on the Mo substrate.The equilibrium contact angle of the Vit.1/Mo is only 6°at 1073 K and 5°at 1123 K.No signifi cant diff usion of Mo into the droplet occurs even at 1173 K with a holding time of~30 min.The interfaces of the Vit.1/Mo samples are sharp,and no interfacial reaction layers form.These fi ndings indicate that pure Mo can be a good roller material for twin-roll casting at high temperatures,and the Mo-made rollers are expected of capability to produce MG strips with good quality.
基金supported by the National Key Project of ScientificTechnical Supporting Programs during the 11th Five-year Plan (No. 2006BAE03B02-2)NSFC Key Program (No. U0734006)
文摘The wetting property of （Sn-9Zn）-2Cu （wt pct） on Ni substrate and the evolution of interracial microstructure in （Sn-9Zn）-2Cu/Ni joints during soldering as well as isothermal aging were studied. The wetting ability of eutectic Sn-gZn solder on Ni substrate was markedly improved by adding 2 wt pct Cu into this solder alloy. Plate-like Cu5Zn8 intermetallic compounds （IMCs） were detected in （Sn-9Zn）-2Cu solder matrix. A continuous NisZn21 IMC layer was formed at （Sn-9Zn）-2Cu/Ni interface after soldering. This IMC layer kept its type and integrality even after aging at 170℃ for up to 1000 h. At the early aging stage （before 500 h）, the IMC layer grew fast and its thickness followed a linear relationship with the square root of aging time. Thereafter, however, the thickness increased very slowly with longer aging time. When the joints were aged for 1000 h, a new IMC phase, （Cu,Ni）5Zn8, was found in the matrix near the interface. The formation of （Cu,Ni）5Zns phase can be attributed to the diffusion of Ni atoms into the solder matrix from the substrate.
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A20113 and 52074198)also supported by the Project for Technology Talents ServinggEnterprises of Hubei Province(Grant No.KJRQ2023000073).
文摘Diffusion couple experiments were performed to study the thermodynamic and kinetic mechanisms of interfacial reactions between the 316L stainless steel and the composite MnO-SiO_(2) oxide during isothermal heating at 1473 K(1200℃)for 1,3,5,and 10 h and at 1173,1273,1373,1473,and 1573 K(900,1000,1100,1200,and 1300℃)for 3 h.Compositional variations in the 316L stainless steel and the composite MnO-SiO_(2) oxide in the vicinity of the steel-oxide interface in each diffusion couple specimen were determined.Before and after isothermal heating,thermodynamic equilibria between the oxide and steel at the interface were estimated in accordance with the calculation of the Gibbs free energy change in the interfacial steel-oxide reactions.The diffusion coefficients of Mn,Cr,and Si in 316L stainless steel under different experimental conditions were quantitatively acquired.The results showed that solid-state interfacial reactions occurred between the Cr in the 316L stainless steel and composite MnO-SiO_(2) oxide during isothermal heating,which resulted in the depletion of Cr and accumulation of Si and Mn in the steel in the vicinity of the steel-oxide interface.The widths of the Crdepleted zone,Mn-accumulated zone and Si-accumulated zone all showed increasing trends with increasing isothermal heating temperature and time.The average values of the diffusion coefficients of Mn,Cr,and Si in the steel at 1473 K(1200℃)were 1.21×10^(^(-14))±2.96×10^(-15),1.69×10^(-14)±2.54×10^(-15),and 1.00×10^(-14)±1.96×10^(-15) m^(2)s^(-1),respectively,and they continued to increase with increasing isothermal heating temperature.
基金the National Natural Science Foundation of China(Grant No.51871184)the Natural Science Foundation of Shandong Province(Grant No.ZR2017MEE038)China Postdoctoral Science Foundation(No.2018M642683)。
文摘The interfacial reaction between Ti-6Al-4V alloy and ZrO2 ceramic mold with zirconia sol binder was investigated by keeping the 12 g alloy melt in a vacuum induction furnace for 15 s.The microstructures,element distribution and phase constitution of the interface were identified by optical microscopy(OM),scanning electron microscopy(SEM)equipped with energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD).The results show that the whole interface reaction layer can be divided into three regions:metal penetration layer,transition layer,and hardened layer according to the structure morphology,which has the characteristics of severe metal penetration,finer lamellar,and coarse oxygen-richαphase,respectively.The erosion of the alloy melt on the ceramic mold promotes the decomposition of zirconia,which leads to the increase of local Zr concentration,greatly increasing the activity coefficient of Ti,aggravating the occurrence of interfacial reaction.Thus,the interfacial reaction shows the characteristics of chain reaction.When the oxygen released by the dissolution of zirconia exceeds the local solid solubility,it precipitates in the form of bubbles,resulting in blowholes at the interface.The result also indicates that the zirconia mold with zirconia sol binder is not suitable for pouring heavy titanium alloy castings.
基金funded by Science Research Project of Hebei Education Department(Grant No.ZD2022042)the Interdisciplinary Research Program of Hebei University(Grant No.DXK202315)+2 种基金the National Natural Science Foundation of China(NSFC)(Grant Nos.52104304 and 51902081)Central Government Guided Local Science and Technology Development Project of Hebei Province(Grant No.246Z4409G)the Scientific Research and Innovation Team of Hebei University(Grant No.IT2023B07).
文摘Li-rich oxides are considered as promising candidate cathode materials for high-energy Li-ion batteries due to their high specific capacity.However,the widespread adoption of Li-rich materials is hindered because of the lack of a stable surface structure to inhibit interfacial side reactions.In this study,a stable LiF@spinel dual shell was constructed on the surface of Li-rich materials,in which spinel is formed by in situ surface recon-struction,and LiF is bonded to the spinel through the Ni–F bond.The spinel serves as a buffer layer between the LiF coating and the Li-rich oxide,providing a three-dimensional Li-ion diffusion channel to improve the Li-ion diffusion coefficient,while the outer LiF plays a critical role in isolating the cathode from the electrolyte.Under the abovementioned dual effect,the interfacial side reactions of Li-rich materials are inhibited,thereby improving their cycle stability.The obtained LiF@spinel-coated Li-rich cathode exhibits an enhanced capacity retention of 81.5%after 150 cycles at a current density of 2 C,which is better than the pristine Li-rich sample(63.2%).These findings indicate that the construction of the LiF@spinel dual shell is a successful strategy for the modification of Li-rich materials.
基金financially supported by the Fundamental Research Funds for Central Universities(No.24D110627)。
文摘The preparation and functionalization of polymeric capsules attract intense attention due to their application in various areas.Herein we presented an amphiphilic alternating copolymer(ACP)-based microcapsule which is both robust and readily-functionalized through interfacial click polymerization.A water-in-oil emulsion was constructed to act as the reaction medium,the hydrophilic 1,3-butadiene diepoxide(BDE)in water phase reacted with the oleophilic 1,4-dibutanedithiol(BDT)in oil phase at the water-oil interface to form the amphiphilic ACP named poly(2,3-dihydroxy butylene-alt-butylene dithioether)(abbreviated as P(DHB-a-BDT)below),which would deposite in situ to form the micro-sized capsules.Significantly,the dried capsules are robust enough to be rehydrated once the water was added and almost restored their original morphologies.Further elucidation showed that the Young's modulus of these capsules exceeded 1 GPa.As long as we know,it is the first time for the mechanical properties of the ACP-based microstructures being investigated.Besides,functionalization could be achieved simultaneously with the formation process.As a proof of concept,positive-charged capsules were successfully obtained through click copolymerization.Stemming from the unique characteristics of amphiphilic ACPs which combined both merits of click chemistry and interfacial reactions,all these features of the current method as well as the resultant capsules may promote the application of the polymeric capsules.
基金supported by the National Natural Science Foundation of China (No. 52374292)China Baowu Low Carbon Metallurgy Innovation Foundation, China (No. BWLCF202309)the Natural Science Foundation of Changsha City, China (No. KQ2208271)。
文摘Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.
基金supported by the National Natural Science Foundation of China (Nos. 21107125, 21577160, 51221892, 51290282 and 41201498)
文摘The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals（·OH）from reactions between recyclable solid catalysts and H2O2 at acidic or even circumneutral pH.Hence,it can effectively oxidize refractory organics in water or soils and has become a promising environmentally friendly treatment technology.Due to the complex reaction system,the mechanism behind heterogeneous Fenton reactions remains unresolved but fascinating,and is crucial for understanding Fenton chemistry and the development and application of efficient heterogeneous Fenton technologies.Iron-based materials usually possess high catalytic activity,low cost,negligible toxicity and easy recovery,and are a superior type of heterogeneous Fenton catalysts.Therefore,this article reviews the fundamental but important interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials..OH,hydroperoxyl radicals/superoxide anions（HO2./O2^-.）and high-valent iron are the three main types of reactive oxygen species（ROS）,with different oxidation reactivity and selectivity.Based on the mechanisms of ROS generation,the interfacial mechanisms of heterogeneous Fenton systems can be classified as the homogeneous Fenton mechanism induced by surface-leached iron,the heterogeneous catalysis mechanism,and the heterogeneous reaction-induced homogeneous mechanism.Different heterogeneous Fenton systems catalyzed by characteristic iron-based materials are comprehensively reviewed.Finally,related future research directions are also suggested.
基金National Natural Science Foundation of China (52301273, 52072411)Science and Technology Innovation Program of Hunan Province (2024RC3222)+3 种基金Key project of scientific research project of Hunan Provincial Department of Education (22A0479)China Postdoctoral Science Foundation (2024M753668)Central South University Innovation-Driven Research Programme (2023CXQD038)Hunan Provincial Postgraduate Research Innovation Programme(CX20240970)。
文摘Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface,predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution.Particularly,the intricate mechanisms behind the electrochemical discrepancies induced by interfacial Zn^(2+)-solvation and deposition behavior demand comprehensive investigation.Organic molecules endowed with special functional groups (such as hydroxyl,carboxyl,etc.) have the potential to significantly optimize the solvation structure of Zn^(2+)and regulate the interfacial electric double layer (EDL).By increasing nucleation overpotential and decreasing interfacial free energy,these functional groups facilitate a lower critical nucleation radius,thereby forming an asymptotic nucleation model to promote uniform Zn deposition.Herein,this study presents a pioneering approach by introducing trace amounts of n-butanol as solvation regulators to engineer the homogenized Zn (H-Zn) anode with a uniform and dense structure.The interfacial reaction and structure evolution are explored by in/ex-situ experimental techniques,indicating that the H-Zn anode exhibits dendrite-free growth,no by-products,and weak hydrogen evolution,in sharp contrast to the bare Zn.Consequently,the H-Zn anode achieves a remarkable Zn utilization rate of approximately 20% and simultaneously sustains a prolonged cycle life exceeding 500 h.Moreover,the H-Zn//NH_(4)V_(4)O^(10)(NVO) full battery showcases exceptional cycle stability,retaining 95.04%capacity retention after 400 cycles at a large current density of 5 A g^(-1).This study enlightens solvation-regulated additives to develop Zn anode with superior utilization efficiency and extended operational lifespan.
基金appreciation to National Natural Science Foundation of China(Nos.52174317,52274337 and U1960203).
文摘To elucidate the formation mechanisms of burn-on sand and metal penetration during sand casting,some laboratory experiments were carried out at different temperatures(1813,1833,1853,and 1873 K)and holding time(20,40,60,and 90 min)to simulate the interaction between ZG13Cr9Mo1VNbN stainless steel and chromite sand.The results demonstrate that the defects primarily consist of a mixture of the liquid phase,chromite,and metal.The main components of the liquid phase are SiO_(2),MnO,MgO,Cr_(2)O_(3),FeO,and Al_(2)O_(3),and the formation of Cr_(2)O_(3)through interfacial redox reactions has been discovered.The presence of a liquid phase plays a pivotal role in influencing burn-on sand and metal penetration.Interface reactions are prioritized,with burn-on sand maintaining a predominant influence.As the liquid phase quantity within the sand escalates,there is a corresponding incremental rise in the incidence of metal penetration.Even a minimal presence of the silicon element in steel can impact the liquid phase’s formation.Moreover,the decomposition or dissolution of chromite sand is a significant factor in the development of burn-on sand and metal penetration.Thus,a thorough investigation into the conditions and contributing factors of this phenomenon is essential for its effective management and mitigation.
基金supported by research grants from the National Natural Science Foundation of China(52173235,22008193,52106110)the Key Research and Development Project of Hainan Province(ZDYF2024SHFZ038)+2 种基金Venture&Innovation Support Program for Chongqing Overseas Returnees(CX2021018)Research Foundation of Chongqing University of Science and Technology(ckrc2021071)Numerical computations were performed on Hefei Advanced Computing Center.
文摘Uncontrolled dendrite growth,sluggish reaction kinetics,and drastic side reactions on the anodeelectrolyte interface are the main obstacles that restrict the application prospect of aqueous zinc-ion batteries.Traditional glass fiber(GF)separator with chemical inertness is almost ineffective in restricting these challenges.Herein,inspired by the ionic enrichment behavior of seaweed plants,a facile biomass species,anionic sodium alginate(SA),is purposely decorated on the commercial GF separator to tackle these issues towards Zn anode.Benefiting from the abundant zincophilic functional groups and superior mechanical strength properties,the as-obtained SA@GF separator could act as ion pump to boost the Zn^(2+)transference number(0.68),reduce the de-solvation energy barrier of hydrated Zn^(2+),and eliminate the undesired concentration polarization effect,which are verified by experimental tests,theoretical calculations,and finite element simulation,respectively.Based on these efficient modulation mechanisms,the SA@GF separator can synchronously achieve well-aligned Zn deposition and the suppression of parasitic side-reactions.Therefore,the Zn‖Zn coin cell integrated with SA@GF separator could yield a prolonged calendar lifespan over 1230 h(1 mA cm^(-2)and 1 mAh cm^(-2)),exhibiting favorable competitiveness with previously reported separator modification strategies.Impressively,the Zn-MnO_(2)full and pouch cell assembled with the SA@GF separator also delivered superior cycling stability and rate performance,further verifying its practical application effect.This work provides a new design philosophy to stabilize the Zn anode from the aspect of separator.
基金the Guangdong Major Project of Basic and Applied Basic Research(2020B0301030006)National Natural Science Foundation of China(52225101 and 52101123)+2 种基金Fundamental Research Funds for the Central Universities(2023CDJYXTD-002)Support Program for Overseas Educated Students Returning to China for Entrepreneurship and Innovation(cx2023020)Chongqing Natural Science Foundation of China(CSTB2023NSCQ-MSX0571).
文摘In the field of particle reinforced magnesium(Mg)matrix composites(MMCs),the interfacial microstructures between reinforcements and Mg matrix are a subject of interest for most researchers.In this work,the 2 wt.%Ti particle reinforced Mg-6Zn alloy composites with different contents(0,0.5,1,1.5,2 wt.%)of Mn were prepared using semi-solid stirring assisted ultrasonic treatment followed by hot extrusion.With the increment of Mn element,the characteristics of mixed-grain structure became obvious and the DRX was inhibited.Meanwhile,the interfacial product gradually changed from MgZn_(2)to Mn_(2)Ti.The tensile test demonstrated that the 2Ti/Mg-6Zn-1.5Mn composite exhibited an excellent strength-ductility synergy,achieving the highest yield stress(YS),ultimate tensile stress(UTS)of 239 MPa,366 MPa,respectively,along with a notable elongation(El.)of 20.6%.The increased strength is mainly due to the grain refinement,the precipitation strengthening,the HDI strengthening and the strong interfacial bonding including the tightly Ti/Mn_(2)Ti bonding and the Mn_(2)Ti/Mg coherent orientation relationship.The ideal El.is the result of fine/coarse bimodal structure and the proper interfacial reaction,which can reduce the occurrence of cracks.
基金financially supported by the National Natural Science Foundation of China(Nos.51827801 and 52371152)the National Key Research and Development Program of China(Nos.2023YFB3710801,2023YFB3710802,and 2021YFB3704002)+1 种基金the Fundamental Research Funds for the Central Universities(No.FRFCU5710001320)the fellowship from the China Scholarship Council(CSC,No.202406120125)for the Visiting PhD Student Program.
文摘Even though vacuum induction melting(VIM)is widely employed in the industrial production of bulk metallic glasses(BMGs),the effect and mechanism of the interfacial reaction between the melt and the oxide ceramic crucible on BMG formations are not yet fully understood.Here,the influences and mechanisms of the interfacial reaction on a Zr-based BMG(Vit 105)subjected to various melting temperatures and holding times are revealed by employing experiments and theoretical calculations.We find that the degree of interfacial reaction is intriguingly correlated with the process parameters during VIM processing,leading to an increase in the oxygen content of the alloy and the reaction layer thickness.Besides,the increase of oxygen content also induces variations in the ordering and shear transformation zone(STZ)size of the BMGs,thus resulting in the precipitation of a nanoscale fcc phase and affecting the mechanical properties and reliability under deformation of the alloy.Furthermore,thermodynamic and kinetic parameters involved in the interfacial reaction,such as the molar Gibbs free energy of each element,the apparent activation energy,etc.,are obtained,providing a comprehensive understanding of the transport processes at play.Our findings provide new insights into the preparation of BMGs by VIM and may be expanded to other melting techniques to accelerate the commercial application of metallic glasses.
文摘development of refractories with low reactivity to rare earth inclusions is an important direction to solve the problem of the nozzle clogging of rare earth steel.La_(2)Ce_(2)O_(7),La_(2)Zr_(2)O_(7),and LaAlO_(3)powders were synthesized using the high-temperature solid-state method with La_(2)O_(3),CeO_(2),ZrO_(2),and Al2O_(3)(particle sizes of 5-10μm)as raw materials,firing at 1400℃for 2 h.Subsequently,La_(2)Ce_(2)O_(7),La_(2)Zr_(2)O_(7),and Y_(2)O_(3)powders were pressed intoφ30 mm×7 mm substrate samples with PVA as a binder;and equal amounts of La_(2)O_(3),La_(2)S_(3),and LaAlO_(3)powders were placed on their surfaces.The samples were then fired at 1550℃for 3 h with carbon embedded.The interfacial reaction of the three rare earth oxide refractories(La_(2)Ce_(2)O_(7),La_(2)Zr_(2)O_(7),and Y_(2)O_(3))with the main rare earth inclusions(La_(2)O_(3),La_(2)S_(3),and LaAlO_(3))in molten rare earth steel was studied.The results show that the La_(2)Ce_(2)O_(7)sample has poor structural stability and readily reacts with La_(2)S_(3),leading to cracking.The La_(2)Zr_(2)O_(7)sample reacts with La_(2)O_(3)and LaAlO_(3)weakly,but performs poor La_(2)S_(3)corrosion resistance.The Y_(2)O_(3)sample demonstrates the weakest interaction with the three rare earth inclusions as well as the most stable structure,indicating significant potential as a specialized anti-clogging lining material for rare earth steel.
