SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4426-y
Biomedical Mg alloys are candidate biodegradable metals for orthopedic and cardiovascular implants, yet their in vivo service life is governed by coupled mechanical-chemical attack that accelerates loss of mechanical integrity. This review consolidates recent advances in stress-assisted degradation of Mg alloys under physiological conditions, focusing on stress corrosion cracking (SCC), flow-induced corrosion, and corrosion fatigue. Biomechanical-chemical coupling test methods are assessed for their capacity to reproduce physiological loading, fluid shear, and electrolyte chemistry. Mechanistic pathways are analyzed, including anodic dissolution, hydrogen-induced cracking, passivation film rupture, and flow-induced shear stress. Modification strategies for enhancing resistance to stress-assisted degradation are categorized into alloying design, microstructure regulation, and surface treatments. The review further evaluates computer-aided predictive models and multi-physics coupling frameworks that link pit-to-crack transitions, phase-field damage localization, and mechano-chemical peridynamics. Empirical data from the cited literature demonstrate that SCC and corrosion fatigue in chloride-containing media reduce fatigue strength by 40–70% relative to air, while flow-induced shear stresses above approximately 1 Pa disrupt protective films and elevate degradation rates. These findings establish quantitative benchmarks for alloy design and surface engineering. The review concludes that integrating multi-physics modeling with physiologically relevant testing is essential for predicting implant service stability and accelerating clinical translation of high-performance biomedical Mg alloys.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3948-7
High-performance thermoelectric materials are typically narrow-band gap semiconductors. Here, by decoupling charge and heat transport in BaZrS3 with a band gap of about 1.9 eV, we made the emerging chalcogenide perovskite a high-performance thermoelectric material with only earth-abundant elements. Our first-principles calculations indicate that the high ionicity of BaZrS3 renders the electrons to propagate mainly through the Zr-4d orbitals, so that isovalent alloying Se on S sites minimally affects its charge transport while effectively suppressing lattice thermal conductivity. Using a flux-assisted solid-state method, we synthesized single-phase BaZrS3(1−x)Se3x samples with 0 ≤ x ≤ 0.25. As an indicator of decoupled charge and heat transport, the electron mobility is found barely degraded with increasing Se content, while the thermal conductivity is significantly reduced from 2.07 to 0.99 W m−1 K−1 at room temperature. This results in a record-high ZT of 0.81 at 750 K, a value never achieved for materials with band gaps greater than 1.5 eV, and the highest among all perovskite materials. Our work not only underscores the potential of wide band gap semiconductors as high-performance thermoelectric materials, but also demonstrates the strategy of decoupling the charge and heat transport for enhancing their thermoelectric performance.
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.