Three types of in-situ TiC(5 vol%,10 vol%and 15 vol%)reinforced high entropy alloy CoCrFeNi matrix composites were produced by vacuum induction *** effect of two extreme cooling conditions(i.e.,slow cooling in fu rnac...
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Three types of in-situ TiC(5 vol%,10 vol%and 15 vol%)reinforced high entropy alloy CoCrFeNi matrix composites were produced by vacuum induction *** effect of two extreme cooling conditions(i.e.,slow cooling in fu rnace and rapid cooling in copper crucible)upon the microstructure and mechanical properties was *** the case of slow cooling in the furnace,TiC was found to form mostly along the grain boundaries for the 5 vol%*** the increase of TiC reinforcements,fibrous TiC appeared and extended into the matrix,leading to an increase in *** ultimate tensile strength of the composites shows a marked variation with increasing TiC content;that is,425.6 MPa(matrix),372.8 MPa(5 vol%),550.4 MPa(10 vol%)and 334.3 MPa(15 vol%),while the elongation-to-failure(i.e.,ductility)*** fracture pattern was found to transit from the ductile to cleavage fracture,as the TiC content *** the samples cooled rapidly in copper crucible,the TiC particles formed both along the grain boundaries and within the *** the increase of TiC volume fraction,both the hardness and ultimate tensile strength of the resulting composites improved steadily while the elongation-to-failure ***,the fast cooling can be used to drastically improve the strength of in-situ TiC reinforced *** example,for the 15 vol%TiC/CoCrFeNi composite cooled in the copper crucible,the hardness and ultimate tensile strength can reach as high as 595 HV and 941.7 MPa,respectively.
As an important research direction in artificial intelligence (AI), machine learning (ML) has been widely used in many complex systems. This paper aimed to study how to improve and train graph based semi-supervised le...
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Piezoelectric ceramic and polymeric separators have been proposed to effectively regulate Li deposition and suppress dendrite growth,but such separators still fail to satisfactorily support durable operation of lithiu...
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Piezoelectric ceramic and polymeric separators have been proposed to effectively regulate Li deposition and suppress dendrite growth,but such separators still fail to satisfactorily support durable operation of lithium metal batteries owing to the fragile ceramic layer or low-piezoelectricity polymer as ***,by combining PVDF-HFP and ferroelectric BaTiO_(3),we develop a homogeneous,single-layer composite separator with strong piezoelectric effects to inhibit dendrite growth while maintaining high mechanical *** squeezed by local protrusion,the polarized PVDF-HFP/BaTiO_(3)composite separator generates a local voltage to suppress the local-intensified electric field and further deconcentrate regional lithium-ion flux to retard lithium deposition on the protrusion,hence enabling a smoother and more compact lithium deposition morphology than the unpoled composite separator and the pure PVDF-HFP separator,especially at high ***,the homogeneous incorporation of BaTiO_(3)highly improves the piezoelectric performances of the separator with residual polarization of 0.086 pC cm^(-2)after polarization treatment,four times that of the pure PVDF-HFP separator,and simultaneously increases the transference number of lithium-ion from 0.45 to *** from the prominent piezoelectric mechanism,the polarized PVDF-HFP/BaTiO_(3)composite separator enables stable cyclic performances of Li||LiFePO_(4)cells for 400 cycles at 2 C(1 C=170 mA g^(-1))with a capacity retention above 99%,and for 600 cycles at 5 C with a capacity retention over 85%.
In joining Fe-alloys and Cu-containing alloys to access the high strength of steels and corrosion resistance of Cu-alloy, cracking is widely observed due to the significant Cu microsegregation during the solidificatio...
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We investigate the mechanisms responsible for the distinct characteristics of certain relaxor ferroelectrics, which display pinched polarization hysteresis loops and recoverable electrostrains, in contrast to the rect...
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We investigate the mechanisms responsible for the distinct characteristics of certain relaxor ferroelectrics, which display pinched polarization hysteresis loops and recoverable electrostrains, in contrast to the rectangular-like polarization hysteresis loops and irrecoverable butterfly-shaped electrostrains observed in typical ferroelectrics. Despite the large number of experimental reports on these materials, the origin of their recoverable electrostrains has remained elusive until now. Using a phase-field model, we study a doped ferroelectric system, considering both local electric fields and local phase-transition temperature variations induced by the local compositional heterogeneity. The directions of local electric fields are randomly distributed along one of the four directions of the spontaneous polarizations in the system. The resulting phase diagram reveals the existence of both normal ferroelectrics and relaxor ferroelectrics, with pinched polarization hysteresis loops and recoverable electrostrains appearing only in the latter. Our simulations shed light on the crucial role of strong local electric fields along spontaneous polarization directions caused by point defects in facilitating nucleation of domains with polarization along the same direction. This, in turn, explains the recoverability of the polarization and electrostrain in certain relaxors, as these local fields can help restore the initial domain-structure, polarization, and strain. These findings provide new insights into the origin of recoverable electrostrains in relaxors, which could have implications for the design of relaxors with large recoverable electrostrains.
This work intends to elaborate a Meshfree approach of a thin plate made by a mixture of a ceramic metal Functionally Graded Material (FGM), which utilises meshless methods PIM and HPIM for the nonlinear buckling analy...
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In this study, WE43 plates in three states (as-extruded T1, post-aging T5 and solution-aging T6) were prepared by extrusion and heat treatment. The microstructures were characterized by using EBSD, TEM and SEM to reve...
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The hot compression tests of 06Cr19Ni9NbN steel were conducted at strains rate of 0.005-5s-1 and temperature of 900-1200 °C on Gleeble1500 thermal mechanical simulation tester. Based on stress-strain data, proces...
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Superior to ferromagnetic (FM) valleytronics, antiferromagnetic (AFM) counterpart exhibits ultradense and ultrafast potential due to their intrinsic advantages of zero stray field, terahertz dynamics, and compensated ...
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In this work, diamond-like carbon (DLC) thin film electrodes were grown on Si substrate by pulsed laser deposition (PLD) technique, and the implication of pulsed laser annealing (PLA) treatment on their electrochemica...
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