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Grain size is a microscopic parameter that has a significant impact on the macroscopic deformation behavior and mechanical properties of twinning induced plasticity (TWIP) steels. In this study, Fe-18Mn-1.3Al-0.6C steel specimens with different grain sizes were first obtained by combining cold rolling and annealing processes. Then the influence of grain size on the plastic deformation mechanisms was investigated by mechanical testing, X-ray diffraction-based line profile analysis, and electron backscatter diffraction. The experimental results showed that the larger grain size could effectively promote twinning during plastic straining, produce an obvious TWIP effect, and suppress the rate of dislocation proliferation. The continuous contribution of dislocation strengthening and twinning functions led to a long plateau in the work-hardening rate curve, and increased the work-hardening index and work-hardening ability. At the same time, the strain could be uniformly distributed at the grain boundaries and twin boundaries inside the grain, which effectively relieved the stress concentration at the grain boundaries and improved the plasticity of deformed samples.

Currently, the major challenge in terms of research on K‐ion batteries is to ensure that they possess satisfactory cycle stability and specific capacity, especially in terms of the intrinsically sluggish kinetics induced by the large radius of K+ ions. Here, we explore high‐performance K‐ion half/full batteries with high rate capability, high specific capacity, and extremely durable cycle stability based on carbon nanosheets with tailored N dopants, which can alleviate the change of volume, increase electronic conductivity, and enhance the K+ ion adsorption. The as‐assembled K‐ion half‐batteries show an excellent rate capability of 468 mA h g−1 at 100 mA g−1, which is superior to those of most carbon materials reported to date. Moreover, the as‐assembled half‐cells have an outstanding life span, running 40,000 cycles over 8 months with a specific capacity retention of 100% at a high current density of 2000 mA g−1, and the target full cells deliver a high reversible specific capacity of 146 mA h g−1 after 2000 cycles over 2 months, with a specific capacity retention of 113% at a high current density of 500 mA g−1, both of which are state of the art in the field of K‐ion batteries. This study might provide some insights into and potential avenues for exploration of advanced K‐ion batteries with durable stability for practical applications. Extremely durable K‐ion batteries with outstanding rate capability and high specific capacity are reported. The as‐assembled half‐cells have an outstanding life span, running 40,000 cycles over 8 months, with a specific capacity retention of 100% at a high current density of 2000 mA g−1, and the target full cells deliver a high reversible specific capacity of 146 mA h g−1 after 2000 cycles over 2 months, with a specific capacity retention of 113% at a high current density of 500 mA g−1, both of which are state of the art in the field of K‐ion batteries.

Flow stress behavior of as-cast dilute Mg-1.2Zn-0.2Y alloy was studied via uniaxial compression test at temperature (300–450°C) and strain rate (0.001–1 s −1 ) using a Gleeble-3500 thermal simulation tester. The constitutive equation with the deformation activation energy of 275.9 kJ/mol was established to describe the thermal deformation behavior of the tested material. The processing maps for the Mg alloy were also constructed based on dynamic material modeling. Optical microscopy, x-ray diffraction, transmission electron microscopy and electron backscatter diffraction were utilized to characterize the microstructures formed at elevated temperature. The results indicated that dynamic recovery was the dominant work-softening mechanism of the Mg-1.2Zn-0.2Y alloy at lower temperature and dynamic recrystallization mainly contributed to the deformation softening at higher temperature. The optimal processing parameters of the safe deformation window were identified as temperature of 420–450°C and strain rate of 0.001–0.01 s −1 .

Al—Mg alloys are an important class of non-heat treatable alloys in which Mg solute and grain size play essential role in their mechanical properties and plastic deformation behaviors. In this work, a cyclical continuous expanded extrusion and drawing (CCEED) process was proposed and implemented on an Al—3Mg alloy to introduce large plastic deformation. The results showed that the continuous expanded extrusion mainly improved the ductility, while the cold drawing enhanced the strength of the alloy. With the increased processing CCEED passes, the multi-pass cross shear deformation mechanism progressively improved the homogeneity of the hardness distributions and refined grain size. Continuous dynamic recrystallization played an important role in the grain refinement of the processed Al—3Mg alloy rods. Besides, the microstructural evolution was basically influenced by the special thermomechanical deformation conditions during the CCEED process.

Currently, a big problem for exploring K-ion half/full batteries is how to bring them with both high specific capacity and long cycling stability simultaneously, in terms of their intrinsically sluggish kinetics of K⁺ with larger radius than that of Li⁺, which often causes huge volume change over the electrochemical reaction. Herein, we report the exploration of high-performance K-ion half/full batteries with superb rate capability and cycle stability based on B-doped porous carbons with increased active sites and improved conductivity. The as-assembled K-ion half cell exhibits an excellent rate capability of 428 mA h g−1 at 100 mA g−1 and a high reversible specific capacity of 330 mA h g−1 with 120% specific capacity retention after 2,000 cycles at 2,000 mA g−1, which is state of the art among those based on carbon materials. Moreover, the as-constructed full cell delivers 98% specific capacity retention over 750 cycles at 500 mA g−1, which is superior to most of the analogs based on carbon materials that have been reported thus far, underscoring their potential applications in advanced energy storage.

SiCp/Al-Fe-V-Si composites exhibit complex deformation behaviors at both room and high temperatures because of the presence of SiC reinforcement particles and numerous fine dispersed Al12(Fe, V)3Si heat-resistant phases. In this work, an artificial neural network (ANN) constitutive model was established to study the deformation behavior of SiCp/Al-7.75Fe-1.04V-1.95Si composites over a wide temperature range based on uniaxial compression. Then, microstructural observation, finite element analysis, and processing maps were utilized to investigate the plastic workability. The results showed that the ANN model fit the experimental stress–strain curves with high accuracy, achieving an R2 value of 0.999. The ANN model was embedded into finite element software to study plastic deformation behaviors, which indicated that this model could accurately compute the plastic and mechanical response during the compressing process. Finally, a thermomechanical processing diagram was developed, revealing that the optimal processing parameters of the SiCp/Al-7.75Fe-1.04V-1.95Si composites were a deformation temperature of 450–500 °C and a deformation rate of 0.1–0.2 s−1.

SiC[sub.p]/Al-Fe-V-Si composites exhibit complex deformation behaviors at both room and high temperatures because of the presence of SiC reinforcement particles and numerous fine dispersed Al[sub.12](Fe, V)[sub.3]Si heat-resistant phases. In this work, an artificial neural network (ANN) constitutive model was established to study the deformation behavior of SiC[sub.p]/Al-7.75Fe-1.04V-1.95Si composites over a wide temperature range based on uniaxial compression. Then, microstructural observation, finite element analysis, and processing maps were utilized to investigate the plastic workability. The results showed that the ANN model fit the experimental stress–strain curves with high accuracy, achieving an R [sup.2] value of 0.999. The ANN model was embedded into finite element software to study plastic deformation behaviors, which indicated that this model could accurately compute the plastic and mechanical response during the compressing process. Finally, a thermomechanical processing diagram was developed, revealing that the optimal processing parameters of the SiC[sub.p]/Al-7.75Fe-1.04V-1.95Si composites were a deformation temperature of 450–500 °C and a deformation rate of 0.1–0.2 s[sup.−] [sup.1].

SiC /Al-Fe-V-Si composites exhibit complex deformation behaviors at both room and high temperatures because of the presence of SiC reinforcement particles and numerous fine dispersed Al (Fe, V) Si heat-resistant phases. In this work, an artificial neural network (ANN) constitutive model was established to study the deformation behavior of SiC /Al-7.75Fe-1.04V-1.95Si composites over a wide temperature range based on uniaxial compression. Then, microstructural observation, finite element analysis, and processing maps were utilized to investigate the plastic workability. The results showed that the ANN model fit the experimental stress-strain curves with high accuracy, achieving an value of 0.999. The ANN model was embedded into finite element software to study plastic deformation behaviors, which indicated that this model could accurately compute the plastic and mechanical response during the compressing process. Finally, a thermomechanical processing diagram was developed, revealing that the optimal processing parameters of the SiC /Al-7.75Fe-1.04V-1.95Si composites were a deformation temperature of 450-500 °C and a deformation rate of 0.1-0.2 s .

The popularly reported energy storage mechanisms of potassium-ion batteries (PIBs) are based on alloy-, de-intercalation-, and conversion-type processes, which inevitably lead to structural damage of the electrodes caused by intercalation/de-intercalation of K⁺ with a relatively large radius, which is accompanied by poor cycle stabilities. Here, we report the exploration of robust high-temperature PIBs enabled by a carboxyl functional group energy storage mechanism, which is based on an example of p-phthalic acid (PTA) with two carboxyl functional groups as the redox centers. In such a case, the intercalation/de-intercalation of K⁺ can be performed via surface reactions with relieved volume change, thus favoring excellent cycle stability for PIBs against high temperatures. As proof of concept, at the fixed working temperature of 62.5 °C, the initial discharge and charge specific capacities of the PTA electrode are ∼660 and 165 mA·h·g−1, respectively, at a current density of 100 mA·g−1, with 86% specific capacity retention after 160 cycles. Meanwhile, it delivers 81.5% specific capacity retention after 390 cycles under a high current density of 500 mA·g−1. The cycle stabilities achieved under both low and high current densities are the best among those of high-temperature PIBs reported previously.

The size and distribution of ceramic particles in aluminum matrix composites have been reported to remarkably influence their properties. For a single ceramic particle, the particle size is too small and prone to agglomeration, which makes the mechanical properties of the composites worse. When the ceramic particle size is too large, the particles and alloy at the interface are not firmly bonded, and the effect of dispersion distribution is not achieved, which will also reduce the mechanical properties of the composites. The multi-size ceramic particles are expected to improve this situation, while their effect on hot workability is less studied. In this study, the hot deformation behavior, constitutive model, processing map and SEM microstructure were investigated to evaluate the hot workability of multi-size SiC particle-reinforced 6013 aluminum matrix composites. The results showed that the increased deformation temperature and decreased strain rate could decrease flow stresses. The flow stress behaviors of the composites can be described by the sine-hyperbolic Arrhenius equation with the deformation activation energy of Q = 205.863 kJ/mol. The constitutive equation of the composites is ε ˙=3.11592×1013sinh0.024909σ4.12413exp−205863RT. Then, the hot processing map of the SiCp/6013 composites was constructed and verified by SEM observations. The rheological instability zone was in the region of a high strain rate. The optimal processing zone for composites was 450~500 °C and 0.03~0.25 s−1. In addition, the strain level was found to increase both the Q value and the area of the instability zone.