Materials & Design最新文献

The guided tissue regeneration (GTR) procedure has become an important process for the treatment of periodontal tissue regeneration, using the membrane as a mechanical barrier to generate a distance across the defect that subsequently allowing bone regeneration. Due to the complexity of periodontal microenvironment caused by bacterial infections, inflammation, and fibrous tissue penetration, the guided tissue regeneration membrane is required to have antibacterial and barrier functions. We developed a loaded methylene blue @ ZIF-8 and hydroxyapatite gradient thermoplastic polyurethane Janus membrane for antibacterial osteogenic and barrier. This Janus membrane with a porous gradient structure was prepared to use phase-conversion method. The rough layer facilitated cell growth and promoted periodontal bone regeneration, whereas the smooth layer isolated the growing fiber tissue.The rapid release of reactive oxygen species in the early stage and continuous release of zinc ions by methylene blue @ZIF-8 can achieve long-term synergistic antibacterial effect, with antibacterial rates of 84 % and 72 % against Escherichia coli and Staphylococcus aureus, respectively, which can effectively reduce the local inflammation caused by bacteria. In summary, we applied the Janus membrane to a rat periodontal bone defect model, and the membrane showed good surgical performance, barrier properties, osteogenic properties, and antibacterial effects, which could have broad application prospects in the treatment of periodontal bone defects.

Developing practical microstructural solutions that simultaneously enable excellent corrosion resistance and mechanical properties in Al-Si-Cu-based alloys has been increasingly in demand. In this study, we attempt to tailor the microstructural evolution to manipulate the mechanical performance and corrosion resistance of Al-7Si-3Cu-(0.4 Mg)-(0.5Ge) alloys fabricated by GPa-level pressure combined with solution and/or aging treatments. It was found that as the solidification pressure increased, the dendritic growth tendency of the α-Al phase became less pronounced, and the modification of eutectic Si became increasingly significant. Complete solid solution alloys were even achieved under 6 GPa. The corresponding kinetic and thermodynamic mechanisms of pressure-induced microstructural evolution were explored in detail. Upon aging treatment, dense irregular Si precipitates emerged from the supersaturated matrix in Al-7Si-3Cu alloys solidified at 5 GPa and 6 GPa, while denser and finer Si precipitates growing along the 〈1 0 0〉_Al directions dominated the matrix of Al-7Si-3Cu-0.4 Mg-0.5Ge alloys, which resulted in considerable enhancement of mechanical properties. The electrochemical corrosion behavior was evaluated in the as-cast and heat-treated conditions. The underlying corrosion mechanisms were discussed in terms of pressure, supersaturated solutes and precipitates. These results reveal the feasibility of designing high-strength and corrosion-resistant Al-Si-Cu series alloys via the manipulation of pressure and heat treatment.

This article proposes a 3-D printed high selectivity triple-band metasurface bandpass filter (BPF) for millimeter-wave applications using groove gap waveguide (GGW) technology. Firstly, the metasurface composed of electromagnetic bandgap elements in GGW technology is designed and analyzed. This configuration effectively mitigates radiation and electromagnetic wave leakage. Subsequently, the multimode split-type topology under the resonances of TE₁₀₂ and TE₂₀₁ modes is utilized to realize a triple-band bandpass response with a compact circuit size. Additionally, the TE₁₀₁ mode considered as an extra energy coupling path is used to introduce more transmission zeros (TZs). Finally, the design prototype is fabricated using 3D printing technology. The measured results are in good agreement with the simulated ones, providing an excellent option for mm-wave wireless communication systems.

The generation of hydrophobic surfaces through laser ablation has garnered considerable attention, particularly for its prospective diverse applications across various industries. This study explores the possibility of generating controllable hydrophobic metasurfaces on Ni-Mn-Ga-based magnetic shape memory (MSM) alloys using femtosecond pulse width laser (FPWL). While hydrophobic surfaces have been achieved on different materials through a variety of different techniques, the research marks the first systematic attempt to tailor hydrophobicity on the surface of Ni-Mn-Ga-based alloys. By characterizing surfaces treated with different laser parameters, the distinct morphologies and hydrophobic properties corresponding to each surface were identified. This newfound control over surface properties with specific machining parameters opens possibilities for applications in microfluidic devices. Additionally, the potential of utilizing the magnetic-field-induced strain (MFIS) exhibited by Ni-Mn-Ga single crystals to alter surface hydrophobicity was explored. Metasurfaces mimicking the dimensional changes in elongation induced by MFIS demonstrated higher static contact angles (SCAs) for water droplets compared to the original surfaces. This approach presents a promising avenue for creating multifunctional microdevices with controllable hydrophobicity using Ni-Mn-Ga-based alloys. Our findings not only offer insights into tailoring of hydrophobic/hydrophilic properties on Ni-Mn-Ga-based MSM alloys but also provide a novel methodology for fabricating functional metasurfaces on other metals.

The CrCoNiSi_0.3 MEA exhibits excellent cryogenic mechanical properties upon both quasi-static and dynamic tension. Under quasi-static tension at cryogenic temperature, the engineering yield and ultimate tensile strengths (UTS) reach 980 MPa and 1800 MPa, respectively, with notable ductility (62 %). The product of UTS and total elongation (TE) is 111.6 GPa %, surpassing most cryogenic high strength-ductility alloys. The significant mechanical strength enhancement is attributed to the denser deformation twins (DTs), multiple twinning, and extensive face-centered-cubic to hexagonal-close-packed (HCP) phase transitions, resulting in a high work hardening capacity. Upon dynamic tension at cryogenic temperature, the strength and strain hardening are further improved, which originates from the thickening DTs and HCP sequence and localized plastic deformation. The effects of temperature and strain rate on phase transition are studied. It is proposed that there is a competing relationship between high strain rate and increased stacking fault energy (SFE) due to temperature rise. The coupling effect of cryogenic temperature and high strain rate inhibits phase transition due to the deformation inhomogeneity in CrCoNiSi_0.3 MEA. The findings make a valuable contribution to understand the influence of temperature and strain rate on the mechanism of FCC-to-HCP phase transition.

Lattice structures possess high specific strength, multi-functionality through innovative structural designs. Here, we proposed an efficient method for the construction of lattice structures by elongating two-dimensional planar patterns along the load direction, which enabled the efficient utilization of 100 % materials for load bearing. Inspired by Chinese Knot (CK), a series of meticulously crafted TC4 lattice structures were fabricated by using selective laser melting. These structures feature nine tubular units arranged in a 3 × 3 matrix interconnected by sixteen parallel plates, and their failure modes were subsequently investigated by uniaxial compression tests. The results show that the specific compressive strength of the CK structure enhances as increasing the density. The detachment between the plate and tube, and the buckling of the plate, lead to the premature failure, which in turn leads to substantial variations in strength, estimated at approximately 80 MPa at ∼ 1.5 g/cm³. When the thickness of the plate exceeds 0.5 mm, and the tube wall thickness exceeds 0.04 mm, the CK structures show high stability and exhibit a 45° shear failure mode. Notably, the specific strength of the CK structure can surpass 330 MPa∙cm³/g, which represents the peak level of specific compressive strength compared to the current TC4 lattice structures.

The drawback of low strength of 304 stainless steel could be overcome by fabricating gradient nanostructures (GNS). However, deformation-induced martensite results in magnetic generation and plasticity degradation. In this work, a single austenitic GNS 304 stainless steel is fabricated by first creating a dual-phase GNS through the ultrasonic surface rolling process (USRP), followed by rapid induction heating. The yield strength of the single austenite GNS (520 MPa) is 1.68 times higher than that of the homogeneous coarse-grained structure (310 MP) without sacrificing plasticity (elongation of 65 %). Quantitative calculations indicate that fine grain, dislocation, twinning, and back-stress strengthening contribute to the strength increment by 30 %, 17.5 %, 23.4 %, and 29.1 %, respectively. Coarse-grained regions deform mainly through FCC-HCP-BCC martensitic transformation, whereas the subsurface layer forms stacking faults and twins due to increased stacking fault energy caused by the reduction in grain size. At the topmost layer, the stress required to activate dislocations is lower than that for twinning. Under high-stress conditions, martensite forms along the nanograin boundaries via a phase transition from FCC to BCC. Consequently, the excellent plasticity of the single austenite GNS stems from the synergistic effects of high back-stress hardening, TRIP and TWIP effect.

Temporomandibular joint osteoarthritis (TMJ-OA) is usually caused by increased friction at the joint interface, excessive release of inflammatory factors and catabolic enzymes, and free radical accumulation, which can lead to accelerated degradation and damage of cartilage. In this study, we develop a biological metabolism-inspired injectable hydrogel crosslinking by hydrazide modified hyaluronic acid (HA-HYD), aldehyde modified hyaluronic acid (HA-ALD), and ε-polylysine coated catalase-mimic nanozyme (mesoporous manganese cobalt oxide). Herein, this nanozyme-reinforced hydrogel with outstanding and durable reactive oxygen species (ROS) depletion capability and biocompatibility can alleviate the oxidative stress microenvironment, improve cell viability and proliferation, as well as up-regulate chondrogenic related gene expression and cartilage matrix formation of chondrocytes in vitro. Intra-articular administration of this engineered hydrogel can effectively scavenge endogenous over-expressed ROS to ameliorate the harsh microenvironment in the cavity of TMJ-OA. The nanozyme-reinforced hydrogel reduced proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and enhance anti-inflammatory cytokines (IL-10) expression, induced polarization of synovial macrophages towards M2 phenotype, alleviated structural damage to the cartilage and subchondral bone of the condyle, thus reducing cartilage matrix destruction and protect cartilage in osteoarthritis. In summary, the bioinspired nanozyme-reinforced hydrogels might be used as a promising ROS scavenger for treatment of TMJ-OA.