With the increasing demand for flexible piezoelectric sensor components,research on polyvinylidene fluoride(PVDF)based piezoelectric polymers is mounting ***,the low dipole polarization and disordered polarization dir...
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With the increasing demand for flexible piezoelectric sensor components,research on polyvinylidene fluoride(PVDF)based piezoelectric polymers is mounting ***,the low dipole polarization and disordered polarization direction presented in PVDF hinder further improvement of piezoelectric ***,we constructed an oriented tertiary structure,consisting of molecular chains,crystalline region,and MXene sheets,in MXene/PVDF nanocomposite via a temperature-pressure dual-field regulation *** highly oriented PVDF molecular chains form approximately 90%of theβ*** addition,the crystalline region structure with long-range orientation achieves out of plane polarization *** parallel orientation arrangement of MXene effectively enhances the piezoelectric performances of the nanocomposite,and the current output of the device increases by nearly 23 *** high output device is used to monitor exercise action,exploring the potential applications in wearable electronics.
Selective area electron diffraction(SAED)patterns can provide valuable insight into the structure of a ***,the manual identification of collected patterns can be a significant bottleneck in the overall phase classific...
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Selective area electron diffraction(SAED)patterns can provide valuable insight into the structure of a ***,the manual identification of collected patterns can be a significant bottleneck in the overall phase classification *** this work,we utilize the recent advances in computer vision and machine learning(ML)to automate the indexing of SAED *** performance of six different ML algorithms is demonstrated using metallic plutonium-zirconium *** most successful approach trained a neural network(NN)to make a classification of the phase and zone axis,and then utilized a second NN to synthesize multiple independent predictions of different tilts in a single sample to make an overall phase *** results demonstrate that automated SAED phase identification using ML is a viable route to accelerate materials characterization.
Defects in materials significantly alter their electronic and structural properties,which affect the per-formance of electronic devices,structural alloys,and functional ***,calculating all the possible defects in comp...
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Defects in materials significantly alter their electronic and structural properties,which affect the per-formance of electronic devices,structural alloys,and functional ***,calculating all the possible defects in complex materials with conventional Density Functional Theory(DFT)can be compu-tationally *** enhance the efficiency of these calculations,we interfaced Density Functional Tight Binding(DFTB)with the Clusters Approach to Statistical Mechanics(CASM)software package for the first *** SiC and ZnO as representative examples,we show that DFTB gives accurate results and can be used as an efficient computational approach for calculating and pre-screening formation ener-gies/convex *** DFTB+CASM implementation allows for an efficient exploration(up to an order of magnitude faster than DFT)of formation energies and convex hulls,which researchers can use to probe other complex systems.
Dielectric capacitors,serving as the indispensable components in advanced high-power energy storage devices,have attracted ever-increasing attention with the rapid development of science and *** various dielectric cap...
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Dielectric capacitors,serving as the indispensable components in advanced high-power energy storage devices,have attracted ever-increasing attention with the rapid development of science and *** various dielectric capacitors,ceramic capacitors with perovskite structures show unique advantages in actual application,e.g.,excellent adaptability in high-temperature *** the optimization of their energy storage performance has become a hot research topic *** review presents the basic principles of energy storage in dielectric ceramics and introduces multi-scale synergic optimization strategies according to the key factors for superior energy storage *** summarizing the common points in numerous works,several universal modification strategies are reviewed,and future research on fatigue fracture of ceramic capacitors under multi-field including but not limited to force,electric,and thermal coupling conditions is also anticipated.
To clarify the correlation of single-crystalline structure with corrosion performance in high-strength TiAl alloys, electrochemical and surface characterization was performed by comparing Ti–45Al–8Nb dual-phase sing...
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To clarify the correlation of single-crystalline structure with corrosion performance in high-strength TiAl alloys, electrochemical and surface characterization was performed by comparing Ti–45Al–8Nb dual-phase single crystals with their polycrystalline counterparts in NaCl solution. Polarization curves show a lower corrosion rate and a higher pitting potential of ~280 mV for the dual-phase single crystals. Electrochemical impedance spectroscopy and potentiostatic polarization plots revealed a higher impedance of the charge transfer through the compact passive film. Surface composition analysis indicated a compact film with more content of Nb, as twice as that in the film on the *** results reflect that the dual-phase Ti–45Al–8Nb single crystals possess a higher corrosion resistance in NaCl solution, compared with their polycrystalline counterpart, arising from a more homogeneous microstructure and composition distribution.
This study presents new methods to effectively model the anisotropic yielding and hardening behavior of laser powder bed fusion fabricated aluminum alloy under both monotonic and cyclic loading *** proposed model comb...
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This study presents new methods to effectively model the anisotropic yielding and hardening behavior of laser powder bed fusion fabricated aluminum alloy under both monotonic and cyclic loading *** proposed model combines the yield surface-interpolation method to accurately describe the anisotropic hardening rates in various directions,with the Chaboche kinematic hardening rule to precisely reflect the cyclic *** numerical implementation of the combined anisotropic and cyclic constitutive model,a fully implicit stress integration algorithm based on return mapping method is ***,the multiple parameters associated with the model are categorized and identified in an uncoupled *** isotropic and cyclic hardening parameters are determined by an inverse method,and the stability of the optimization outcomes is validated by applying different starting points for the ***,the back-stress effect on the identification of anisotropic parameters associated with the stress invariant-based Hill48 yield function is considered for the first *** consideration leads to an improved prediction accuracy compared to the identification of anisotropic parameters without considering back-stress *** combined anisotropic and cyclic constitutive model,along with the calibrated parameters,are proven capable of accurately reproducing the intricate deformation behavior of laser powder bed fusion fabricated AlSi10Mg.
The goal of this work is to improve the Ti–6Al–4V alloy's hardness and tribological behavior. Coaxial laser surface cladding was used to develop intermetallic layers of nickel (Ni), cobalt (Co), and titanium (Ti...
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The linear variable differential transformer (LVDT) is widely used for displacement measurement in both industry and research due to its high accuracy and working ability in harsh environments. However, the lack of a ...
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Metallic alloys with high strength and large ductility are required for extreme structural ***,the achievement of ultrahigh strength often results in a substantially decreased ***,we report a strategy to achieve the s...
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Metallic alloys with high strength and large ductility are required for extreme structural ***,the achievement of ultrahigh strength often results in a substantially decreased ***,we report a strategy to achieve the strength-ductility synergy by tailoring the alloy composition to control the local stacking fault energy(SFE)of the face-centered-cubic(fcc)matrix in an L1_(2)-strengthened superlattice *** a proof of concept,based on the thermodynamic calculations,we developed a non-equiatomic CoCrNi_(2)(Al_(0.2)Nb_(0.2))alloy using phase separation to create a near-equiatomic low SFE disordered CoCrNi medium-entropy alloy matrix with in situ formed high-content coherent Ni_(3)(Al,Nb)-type ordered nanoprecipitates(∼12 nm).The alloy achieves a high tensile strength up to 1.6 GPa and a uniform ductility of 33%.The low SFE of the fcc matrix promotes the formation of nanotwins and parallel microbands during plastic deformation which could remarkably enhance the strain hardening *** work provides a strategy for developing ultrahigh-strength alloys with large uniform ductility.
Deformation twinning is profusely activated in the Mg alloys due to lower critical resolved shear stress(CRSS) compared to the non-basal slip systems(prismatic and pyramidal ) and plays a significant role in texture r...
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Deformation twinning is profusely activated in the Mg alloys due to lower critical resolved shear stress(CRSS) compared to the non-basal slip systems(prismatic and pyramidal ) and plays a significant role in texture reorientation, grain refinement and enhancement of mechanical performance. Twinning is a sequential process comprising twin nucleation, twin propagation and twin growth, hence several intrinsic and extrinsic parameters that facilitate or suppress the process have been critically reviewed. The dependence of twinning on the grain size, deformation temperature, favorable grain orientation and shear strain have been thoroughly discussed in the context of published literature and an attempt has been made to provide a benchmark conclusive finding based on the majority of works. Furthermore, the subsequent effect of twinning on the mechanical performance of Mg alloys, including ductility, formability and tension-compression asymmetry has been discussed in detail. Lastly, the stability of twins, including stress and thermal stability, is summarized and critical issues related to pertinent bottlenecks have been addressed.
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