Monovalent anions,with relatively low charge density,exhibit weak bond energy with Zn2+ions,which facilitates the solubility of Zn salts and the regulation of solvation *** this study,zinc bis(aminosulfate)(Zn(NH2...
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Monovalent anions,with relatively low charge density,exhibit weak bond energy with Zn2+ions,which facilitates the solubility of Zn salts and the regulation of solvation *** this study,zinc bis(aminosulfate)(Zn(NH2SO3)2) with a monovalent anion,NH2SO3-,was synthesized and dissolved in different ratios of dimethyl sulfoxide (DMSO) and H2O as electrolytes for Zn-ion batteries (ZIBs).From the perspective of game theory,the influences of DMSO and H2O on the solvation structure and electrochemical performance of the Zn(NH2SO3)2based electrolytes has been meticulously *** and spectra analysis indicate that DMSO molecules are reluctant to penetrate the primary solvation structure of Zn2+***,increasing DMSO in electrolytes can induce a transition from solvent-separated ion pairs (SSIP) to contact ion pairs (CIP),resulting in an enrichment of anions in the primary solvation *** alteration can significantly suppress parasitic reactions,enhance nucleation density,and refine the deposition morphology during the Zn plating process,leading to superior cyclic stability and high coulombic efficiency (CE) of Zn//Cu and Zn//Zn ***,the enrichment of anions in the primary solvation structure also inhibits the activity of Zn2+ions,amplifies the polarization effect,and engenders a sluggish ionization dynamics,resulting in the low energy conversion efficiency of the *** findings underscore the influence of the anion ratio within the primary solvation structure on electrochemical properties of electrolytes for ZIBs,which may be a pivotal determinant in the Zn deposition process.
Silicon(Si)has emerged as a promising anode material for lithium-ion batteries(LIBs)due to its extremely high theoretical capacity of 4200 mAh·g^(-1).However,its practical application is limited by several critic...
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Silicon(Si)has emerged as a promising anode material for lithium-ion batteries(LIBs)due to its extremely high theoretical capacity of 4200 mAh·g^(-1).However,its practical application is limited by several critical challenges,including severe volume expansion and poor electrical ***,we employ a two-dimensional(2D)oxygen modification engineering approach to fabricate 2D oxygen-functionalized CaSi_(2)(CaSi_(2)O_(x))*** the preparation of 2D CaSi_(2) layers,O atoms are gradually incorporated onto their *** resulting 2D CaSi_(2)O_(x) layers have a thickness of 3-5 nm,closely matching the theoretical thickness of 6-10 *** used as lithium anodes,the 2D CaSi_(2)O_(x) layers exhibit exceptional electrochemical performance,maintaining stability over 3000 cycles at an ultrahigh current density of 30 A·g^(-1).By tailoring the surface properties,their pseudocapacitive charge storage mechanism is significantly enhanced,effectively overcoming the intrinsic limitations of traditional Si *** study highlights the promise of 2D surfaceengineering in the development of advanced materials for next-generation LIBs.
The evaporation and dilution of substrate seriously limit the performance of laser cladding coatings on magnesium *** order to overcome the above shortcomings,a multi-step ultrasonic assisted laser remelting technolog...
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The evaporation and dilution of substrate seriously limit the performance of laser cladding coatings on magnesium *** order to overcome the above shortcomings,a multi-step ultrasonic assisted laser remelting technology was proposed to improve the performance of the *** this work,a novel Cu_(2.3)Al_(1.3)Ni_(1.7)SnCr_(0.3) multi-principal element alloy coating(MPEAC)was prepared on the surface of mag-nesium *** techniques such as transmission electron microscopy(TEM),electron back scatter diffraction(EBSD)and scanning electron microscopy(SEM)were employed to characterize the microstructure and phase composition of the *** the phase structure and morphology at the interface between the coating and the substrate were also studied via focus ion beam(FIB)and TEM *** addition,the corrosion and wear resistance ability of the coatings were monitored by potentiodynamic polarization(PDP),and electrochemical impedance spectroscopy(EIS),hardness and friction *** results show that Cu_(2.3)Al_(1.3)Ni_(1.7)SnCr_(0.3) MPEAC with ultrasonic assisted is composed of FCC phase and eutectic phases(Cu_(10)Sn_(3) and Cu_(2)Ni_(3)Sn_(3)).Due to the forced convection generated by ultrasonic waves,some Cu and Ni phases are precipitated around Cu_(2)Ni_(3)Sn_(3) phases,which is beneficial to enhance the corrosion *** of the grain refinement effect caused by ultrasonic,the wear resistance of the coating is also ***,ultrasonic vibration can effectively weaken and eliminate the texture density of the Cu_(2.3)Al_(1.3)Ni_(1.7)SnCr_(0.3) MPEAC fabricated by laser cladding.
Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy ***,the high-temperature strength of existing...
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Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy ***,the high-temperature strength of existing cast aluminum alloys is always limited to about 100 MPa at 350℃due to coarsening and transformation of strengthening ***,we reveal that the yield strength and ultimate tensile strength of the T6 state Al-8.4Cu-2.3Ce-1.0Mn-0.5Ni-0.2Zr alloy at 400◦C increase by 34%and 44%after re-aging at 300℃for 100 h,and its thermal strength exhibits distinguished ad-vantage over traditional heat-resistant aluminum *** enhanced elevated-temperature strength is attributed to the reprecipitation of the Ni-bearing T-Al_(20)Cu_(2)Mn_(3)phase,whose number density increases over one *** significant segregation of Ni,Ce,and Zr elements at the interfaces helps improve the thermal stability of the T *** thermostable T phase effectively strengthens the matrix by in-hibiting dislocation ***,a highly interconnected 3D intermetallic network along the grain boundaries can still remain after long-term re-aging at 300℃,which is conducive to imposing a drag on the grain boundaries at high *** finding offers a viable route for enhancing the elevated-temperature strength of heat-resistant aluminum alloys,which could provide expanded opportunities for higher-temperature applications.
The fast fabrication of high-quality anode layers of solid oxide fuel cells (SOFCs) is a key factor for their efficient applications. In this work, a one-step method of cathode plasma electrolytic deposition (CPED) is...
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Microstructure regulation via short-time heat treatment is conducive to the optimization in the microstructure and properties of precipitable magnesium(Mg)alloys,but there is currently a lack of relevant *** this work...
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Microstructure regulation via short-time heat treatment is conducive to the optimization in the microstructure and properties of precipitable magnesium(Mg)alloys,but there is currently a lack of relevant *** this work,the microstructure evolution of a Mg-RE-Ag alloy during different short-time heat treatments was characterized and *** results show that extreme short-time heat treatment(ESHT,e.g.,2 min)at 450-480℃can greatly increase solute concentration in Mg matrix through the rapid re-dissolution of the second-phase and simultaneously maintain fine grains,while the ESHT at a too high temperature(e.g.,510℃)is not suitable due to excessive grain growth and coarse second phase regenerated at grain *** is found that 480℃is the approximate critical temperature for appropriate ESHT,and further prolongation of the time will lead to excessive grain *** is suggested that in addition to grain boundary migration,grain rotation is activated,resulting in the annihilation of high-angle grain boundaries with relatively low misorientation,as well as the reduction in the ability of the residual second phase to pin grain *** addition,the reasons for the abnormal grain boundary segregation and grain boundary continuous phase were analyzed from the perspective of interfacial *** study provides a basis for effective microstructure regulation of Mg-RE alloys.
Boron suboxide(B6O)is recognized as a superhard material with a low mass density,high resistance to chemical wear,and excellent wear *** its desirable properties,the limited fracture tough-ness of B6O restricts its ap...
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Boron suboxide(B6O)is recognized as a superhard material with a low mass density,high resistance to chemical wear,and excellent wear *** its desirable properties,the limited fracture tough-ness of B6O restricts its application in industrial *** study presents the structural and me-chanical characterization of B6O-SiC nanocomposites,which were synthesized via a high-pressure high-temperature sintering process of B6O powders and SiC *** sintering process induced fragmen-tation of SiC whiskers,resulting in the homogenous distribution of SiC fragments within the B6O *** increase in SiC content was observed to decrease the composite's hardness,while initially reducing then enhancing its *** nanocomposites containing 20 wt%and 30 wt%SiC whiskers exhibited significant improvements in fracture toughness,averaging 6.5 MPa m1/2 and 7.0 MPa m1/2,respectively-approximately threefold the toughness of polycrystalline B6O-while sustaining high hardness values of 36.3 GPa and 35.6 GPa on *** analyses revealed that the composites'superior me-chanical performance is due to the presence of strong grain boundaries,as well as a high density of nan-otwins and stacking *** findings demonstrate a viable method for producing B6O-based nanocom-posites with enhanced hardness and toughness,potentially expanding their industrial applicability.
In this study, effects of initial orientation on microstructure evolution and mechanical properties of AZ31 Mg alloy sheets via accumulated extrusion bonding(AEB) was systematically studied. The samples with RD and TD...
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In this study, effects of initial orientation on microstructure evolution and mechanical properties of AZ31 Mg alloy sheets via accumulated extrusion bonding(AEB) was systematically studied. The samples with RD and TD parallel to extrusion direction(ED) were labeled as RED and TED, respectively. RD and TD pieces alternately stacked was named as RTED. The results revealed that under three-dimensional compressive stress, {10-12} tensile twinning dominated the first stage deformation in container. As the plunger continuous press down, dynamic recrystallization(DRX) occurred, and the newly fine DRXed grains along original and twin grain boundaries gradually consumed the matrix and twin grains. The microstructure was completely transformed into recrystallized grain structure at sizing band with an average grain size of ~0.9 μm in TED sample, smaller than that of RED *** the alloys extruded out of the die, DRXed grains significantly grew to ~4.5 μm and 3.5 μm for RED and TED samples, respectively. A laminated microstructure was obtained with average grain sizes of~4.4 μm in RD layers and 3.5 μm in TD layers for RTED sample. The AEB processed samples exhibited an ED-tilt double-peak basal texture with similar texture intensity. The tensile tests results indicated that attributed to the combined effect of grain refinement and texture evolution, the yield strength and fracture elongation of RED and TED samples was significantly improved. The heterogeneous microstructure in RTED sample induced an extra work hardening(HDI-work hardening) in tensile deformation and resulted in a further improved elongation of 32.0%.
The residual stress field induced by surface strengthening processes such as mechanical shot peening and other forms of plastic deformation does not generally exhibit a simple"monotonic"distribution *** rese...
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The residual stress field induced by surface strengthening processes such as mechanical shot peening and other forms of plastic deformation does not generally exhibit a simple"monotonic"distribution *** researchers have analyzed this fact from a mechanical perspective based on Hertz ***,the micro/nano-scale microstructural changes corresponding to the distribution of residual stress fields still appear to be *** this study,we focused on a widely used material in aviation manufacturing,namely nickel-based superalloy GH4169,as our experimental *** subjected GH4169 alloy to me-chanical strengthening treatment using a shot peening intensity of 0.25 mmA,followed by quantitative testing of micromechanical performance indicators such as microhardness and residual *** thor-oughly investigate the relationship between micromechanical properties and microstructure changes,we utilized transmission electron microscopy(TEM)to observe and analyze shot-peened materials at differ-ent *** findings revealed that the most severe microstructural distortion induced by mechanical shot peening in GH4169 alloy was likely to occur within a depth range of 25 to 75 *** observation aligns with the actual phenomenon that the maximum microhardness and maximum residual compres-sive stress did not manifest on the outermost surface of the *** presenting a detailed analysis of deformation defects such as dislocations,stacking faults,and twinning in different depths of mechan-ically strengthened layers,our study contributes to a deeper understanding and practical application of post-processing technologies based on plastic deformation.
The present work aims to create lattice distortion and optimize the surface oxygen vacancy(OV)concentration in a model spinel(Co_(0.2)Cr_(0.2)Fe_(0.2)Mn_(0.2)Ni_(0.2))_(3)O_(4)high-entropy oxide(HEO)through a heteroat...
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The present work aims to create lattice distortion and optimize the surface oxygen vacancy(OV)concentration in a model spinel(Co_(0.2)Cr_(0.2)Fe_(0.2)Mn_(0.2)Ni_(0.2))_(3)O_(4)high-entropy oxide(HEO)through a heteroatom La^(3+)doping *** demonstrated,La^(3+)with a large radius can be doped successfully into the spinel lattice of(Co_(0.2)Cr_(0.2)Fe_(0.2)Mn_(0.2)Ni_(0.2))_(3)O_(4),thereby not only causing lattice distortion to increase oxygen vacancies but also refining crystalline grains and improving the specific *** with the(Co_(0.2)Cr_(0.2)Fe_(0.2)Mn_(0.2)Ni_(0.2))_(3)O_(4)anode,the(La_(0.01)CoCrFeMnNi)_(3/5.01)O_(4) anode with moderate doping exhibits excellent cycling performance(1228 mAh·g^(−1)after 400 cycles at 0.2 A·g^(−1))and yields an increase of 75%rate capability at 3 A·g^(−1)(420 mAh·g^(−1)at 3 A·g^(−1)).The desirable kinetic transport of electrons and diffusion of Li+within the moderately La^(3+)-doped anode and the synergistic interfacial pseudocapacitive behavior satisfy the redox reaction at a high rate,thus increasing rate capability.
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