Stacking fault energies (SFEs) are fundamental to deformation mechanisms in crystalline materials, yet discrepancies between theoretical predictions and experiment remain. Here we evaluate the Olson–Cohen (OC), Ising, and partial separation (PS) models using a unified EAM/MEAM interatomic potential framework to enable a controlled comparison of the different approaches. For most fcc metals, the PS model predicts SFEs consistent with the OC and Ising models, whereas larger deviations occur when equilibrium partial separations are too small for the model to remain valid. Similar material-dependent behavior is observed for concentrated alloys. Simulations of Ni reveal that finite specimen thickness can influence the apparent PS-based SFE, a size effect expected to intensify in materials with wider separations. Furthermore, simulations of metastable fcc Co demonstrate that the apparent partial separation is sensitive to boundary conditions. These results clarify the applicability and limitations of the PS approach and highlight the importance of carefully verifying specimen size and boundary conditions when determining SFEs from partial separations.
As a key component for wearable devices and human–computer interaction (HCI) perception, flexible pressure sensors are rapidly evolving from single-matric optimization toward intelligent and multimodal integration. This paper reviews recent advances in piezoresistive, capacitive, piezoelectric, triboelectric, and multimodal flexible pressure sensors, with emphasis on materials such as PDMS and MXene. We summarize how microstructural engineering—including gradient porous architectures, freeze-cast structures, and electrospun network—enhances sensitivity, linearity, and stability. The integration of machine learning and deep learning methods is discussed, highlighting the capability of representative networks (CNN–BiLSTM) in capturing nonlinear temporal dynamics and decoding complex pressure signals. Experimental demonstrations, such as Morse-code recognition via high-precision acquisition systems, are presented to illustrate the potential of flexible pressure sensing coupled with deep learning. Finally, future directions are outlined from the perspective of synergistic material–structure–circuit–algorithm co-design, targeting intelligent perception and edge deployment.
Flexible electroactive polymer composites have attracted considerable attention for next- generation wearable sensors, energy harvesters and flexible electronic application. In this novel material, PVDF@ZnO/CuO/NiO ternary nanocomposites films were successfully fabricated using a simple solution casting technique by adopting a synergistic multi-oxide reinforced strategy to enhance the electroactive performance of PVDF. The structural, morphological, dielectric, polarization and mechanical properties of the fabricated films were systematically investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), dielectric measurements, polarization electric field (P-E) analysis and tensile testing. XRD analysis revealed enhanced crystallinity and stabilization of the electroactive β-phase following nanoparticle incorporation. FTIR and Raman analyses confirmed strong interfacial interactions between the metal oxide nanoparticles and the PVDF matrix. SEM images demonstrated a homogeneous distribution of ZnO, CuO, and NiO nanoparticles, while EDX elemental mapping verified their uniform dispersion and compositional purity. Dielectric measurements performed over the frequency range 60 Hz to 10MHz exhibited increased dielectric permittivity with low dielectric loss at higher frequencies, primarily due to enhanced interfacial and dipolar polarization mechanisms. P-E measurements revealed an enhanced polarization response with a nonlinear increase in polarization upon increasing the applied electric field; however, the absence of a fully saturated and closed hysteresis loop indicates that the response arises from the combined contributions of PVDF dipolar polarization, Maxwell–Wagner–Sillars interfacial polarization and field dependent charge transport. At higher applied voltages, charge injection, leakage conduction and space charge effects contribute to the observed open and lossy P-E characteristics. Tensile testing revealed that the incorporation of the multi-oxide fillers improved the flexibility of the composite films, although the tensile strength decreased compared with pristine PVDF. The synergistic combination of ZnO, CuO, and NiO nanoparticles significantly improves the structural, dielectric, polarization and functional properties of PVDF, demonstrating the potential of these ternary nanocomposite films for advanced flexible sensors, energy harvesting, next generation flexible electronic applications.
Microstructure, texture, and tensile properties of a heavily cryo-rolled and annealed novel (FCC+BCC/B2) Al0.3CoCr1.3FeMnNi0.7 high-entropy alloy (HEA) were investigated in this work. Cryo-rolling resulted in the progressive development of deformation heterogeneities, deformation-induced ultrafine/nano lamellar structure, and a brass-type deformation texture typical of low SFE alloys. Annealing below 1000 ℃ led to an ultrafine (< 1 µm) recrystallized microstructure, profuse Ni-Al-rich B2 precipitates, and Cr-rich σ precipitates, whereas annealing at higher temperatures resulted in a (FCC+BCC) dual-phase microstructure. Meanwhile, the recrystallization texture was weak, featured by retained α-fiber (ND//<110>) and a large fraction of random components. Suitably annealed HEA exhibited an attractive balance of strength (YS 786 MPa, UTS 934 MPa), ductility ( 13
The low absorptivity of copper-chromium-zirconium (CuCrZr) alloys for conventional near-infrared laser radiation and their high thermal conductivity hinder high-quality fabrication by laser powder bed fusion (LPBF). This study investigated the effects of laser power (P), scanning speed (v), and the corresponding linear energy density (LED, defined as the laser energy input per unit scan length, LED = P/v) on the build quality and solidification microstructure of CuCrZr fabricated by green LPBF. An appropriate increase in laser power promoted melting and remelting and facilitated molten metal flow and spreading, thereby suppressing balling and reducing surface roughness. Within the investigated parameter range, porosity generally decreased with increasing scanning speed. Combining relatively high laser power and scanning speed may help ensure sufficient powder melting while limiting overheating, thereby improving melt pool stability and build quality. The relative density first increased and then decreased with increasing LED, reaching a maximum value of 99.28
