SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3883-2
Tensile stress annealing (TSA) is an effective strategy for tailoring magnetic anisotropy and high-frequency performance in nanocrystalline soft magnetic alloys. Here, we systematically investigate the influence of TSA on the microstructure, magnetic domain evolution, and permeability stability of Fe69.5Co3Nb2Mo1.5Si14B9Cu1 nanocrystalline alloys. Across all applied stresses (0–300 MPa), the alloys retain an ultrafine grain size (≤11 nm), yet the induced uniaxial anisotropy constant (Ku) rises sharply from 22.5 to 665 J/m3. This increase in Ku refines the magnetic domain structure, reducing average domain width from 110 to 36 μm, and shifts the magnetization mechanism from domain-wall displacement to rotation-dominated reversal. Quantitative correlation between Ku, domain structure, and effective permeability (μe) reveals that higher stress suppresses μe at low frequencies but yields exceptional frequency stability: μe ≈ 2330 is maintained up to 1 MHz at 50 MPa, and μe ≈ 585 remains constant from 1 kHz to 10 MHz at 300 MPa. These findings demonstrate that stress-induced anisotropy is a decisive factor in governing high-frequency magnetic response, offering both mechanistic insight and a practical framework for designing next-generation soft magnetic materials for precision current transformers, EMC filters, and MHz-class power electronics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4086-4
Interventional therapy has emerged as a transformative alternative to open surgery owing to its minimal invasiveness and fast recovery. However, it still presents risks of iatrogenic injury from vascular access, necessitating prompt and reliable vascular closure. Although various closure systems have been developed, they often suffer from complicated deployment procedures, potential for loosening, and risk of device migration. Herein, we develop a smart self-deployable vascular closure device enabled by a semi-interpenetrating network (sIPN) that synergistically integrates a programmable shape memory effect and robust tissue adhesion. The sIPN was designed by interpenetrating flexible, dopamine-functionalized poly(tetrahydrofuran) (PTD) chains into a photo-crosslinkable poly(ε-caprolactone)-based copolymer (PCC) network. The vascular closure model was fabricated via a UV-assisted fused deposition modeling printing strategy, significantly reducing mechanical anisotropy while facilitating structural customization. The resulting device exhibits autonomous self-deployment at 37 °C, along with reliable tissue adhesion under physiological conditions (maximum shear strength of 150.5 kPa). In vitro, the material demonstrates exceptional hemocompatibility (below 3%) and excellently enhanced cell migration (up to 38.9%). In vivo, immunofluorescence analysis reveals a promotion for CD31 (162.18%) and αSMA (154.93%) compared to the control group. These results highlight the PTD/PCC sIPN as a bioadaptive, multifunctional material platform for intelligent vascular closure, offering great promise for clinical translation in interventional therapies.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4051-x
Graphite lubricants are critical for high-quality and high-efficiency drawing of refractory metal wires, yet inadequate dispersion stability frequently challenges their practical application. Inspired by the bio-surfactant synergic mechanism that combines different bio-surfactants to collectively reduce surface energy and friction, a binary anionic surfactant system comprising sodium dodecyl benzene sulfonate (SDBS) and sodium lignosulfonate (SL) was engineered to enhance dispersion and stability via a synergistic effect. The synergistic parameter β was calculated to be −2.34, indicating strong synergism. The resulting graphite lubricants maintained homogeneous dispersion for up to 60 days. Molecular dynamics (MD) simulations combined with density functional theory (DFT) calculations confirmed that the synergistic effects originate from steric hindrance, electrostatic repulsion, π-π stacking, and hydrogen bonding. These hierarchical secondary interactions collectively increased the interfacial formation energy at the graphite/surfactant/water tri-phase interface, thereby effectively wetting particle powders and enhancing stability. During metal wire drawing, the graphite lubricants reduced the friction coefficient between the die and metal wires to 0.06, ultimately enabling drawn tungsten wires with superior surface integrity, expanded loop diameter, and enhanced tensile strength relative to single-surfactant benchmarks. This study provides experimental and theoretical guidance to design effective graphite lubricants for high-quality drawn metal wires.