Search Results (475)

Titanium implants are subjected to various surface treatments to improve their in vivo function. In this study, we evaluated the usefulness of titanium implants treated with acid, NaOH, CaCl₂, heat, and ICl₃ (Ac-NaCaThIo) in terms of in vivo bone-bonding strength, bone formation, and histological anti-inflammatory properties. Iodine-loaded experimental dental implants and commercial control dental implants were placed in rabbit femurs, and bone-bonding strength was evaluated by measuring the implant stability quotient (ISQ), bone formation using tissue specimens, and the effect of iodine using thyroid-stimulating hormone (TSH) levels. Iodine-loaded titanium plates and untreated titanium plates were placed on rat skulls and inoculated with Streptococcus mitis (S. mitis) solution to evaluate anti-inflammatory properties. Consequently, the experimental implants did not demonstrate non-inferiority in bone-bonding strength (ISQ) compared with the controls; however, histological specimens revealed dense bone contact and favorable bone formation. TSH levels showed no differences at 13 weeks, indicating no long-term adverse effects of iodine. The experimental tissue specimens of the soft tissue had fewer inflammatory cells than the control at 2 weeks after placement, demonstrating an anti-inflammatory effect. These results suggest that, although non-inferiority in ISQ was not demonstrated, Ac-NaCaThIo-treated implants showed favorable bone formation, dense bone contact, anti-inflammatory properties, and biosafety, indicating potential for future applications. Full article

Micro-arc oxidation (MAO) technology demonstrates remarkable advantages in fabricating ceramic coatings on lightweight alloys. For aluminum alloys, MAO rapidly forms dense, pore-free ceramic layers within minutes, significantly enhancing corrosion and wear resistance at low processing costs. In magnesium alloys, optimized electrolyte compositions and process parameters enable composite coatings with a combination of high hardness and self-lubrication properties, while post-treatments like laser melting or corrosion inhibitors extend salt spray corrosion resistance. Titanium alloys benefit from MAO coatings with exceptional interfacial bonding strength and mechanical performance, making them ideal for biomedical implants and aerospace components. Notably, dense ceramic oxide films grown in situ via MAO on high-entropy alloys (HEAs) triple surface hardness and enhance wear/corrosion resistance. However, MAO applications on steel require pretreatments like aluminizing, thermal spraying, or ion plating. Current challenges include coating uniformity control, efficiency for complex geometries, and long-term stability. Future research focuses on multifunctional coatings (self-healing, antibacterial) and eco-friendly electrolyte systems to expand engineering applications. Full article

Friction dampers are widely used in building seismic protection due to their excellent shock-absorbing performance and reliable operation. To clarify the influence of friction plate material properties on the hysteretic behavior and stability of friction dampers, this study selected three materials with distinct physical properties (density, hardness, and stiffness)—titanium alloy, brass, and zirconia ceramic—as friction plate candidates. Three sets of low-cycle reciprocating load tests were designed to obtain the hysteretic curves of dampers with different friction plates and analyze their energy dissipation capacity and operational stability. Results show that the hysteretic curves of the copper-steel and titanium-steel plate specimens are close to the ideal rectangular shape, with symmetric force–displacement relationships and stable energy dissipation. The copper-steel plate exhibits strong energy dissipation capacity and high cost-effectiveness, while the titanium-steel plate has moderate energy dissipation capacity but stability comparable to that of the copper-steel plate. In contrast, the friction force of ceramic-steel plate specimens shows obvious divergence as displacement increases, leading to poor overall stability. The friction coefficient between the friction plate material and the main plate material exerts a significant influence on the damper’s energy dissipation, and a stable friction mode serves as a guarantee for its normal operation. Full article

The reconstruction of segmental bone defects requires patient-specific scaffolds that combine mechanical safety, biological functionality, and rapid manufacturing. We converted CT-derived mandibular geometry into a functionally graded Ti-6Al-4V lattice and optimised porosity, screw layout, and strut thickness through a cyber-physical loop that joins high-fidelity FEM, millisecond ANN, and a BN for uncertainty quantification. Fifteen candidate scaffolds were fabricated by direct metal laser sintering and hot isostatic pressing and were mechanically tested. FEM predicted stress and stiffness with 98% accuracy; the ANN reproduced these outputs with 94% fidelity while evaluating 10,000 designs in real time, and the BN limited failure probability to <3% under worst-case loads. The selected 55–65% porosity design reduced titanium use by 15%, shortened development time by 25% and raised multi-objective optimisation efficiency by 20% relative to a solid-plate baseline, while resisting a 600 N bite with a peak von Mises stress of 225 MPa and micromotion < 150 µm. Integrating physics-based simulation, AI speed, and probabilistic rigour yields a validated, additively manufactured scaffold that meets surgical timelines and biomechanical requirements, offering a transferable blueprint for functional scaffolds in bone and joint surgery. Full article

Ti80 alloy is one of the most commonly used marine titanium alloys but faces cold cracking risks in thick plate welding. Understanding the relationship between restraint intensity and welding residual stress is critical for industrial applications. This study employs finite element methods to quantify the restraint intensity of Lehigh specimens and establish its quantitative link with welding residual stress in Ti80 alloy. Simulations reveal that restraint intensity increases linearly with plate thickness and decreases linearly with slot depth. A binary linear regression model accurately predicts restraint intensity with relative error of less than 6%. Furthermore, welding simulations demonstrate that residual stress on the weld bead’s upper surface increases exponentially with restraint intensity, while the lower surface shows a linear increase. Exponential and linear fits were applied to predict residual stress on the upper and lower surface, respectively. Validation confirms prediction errors for residual stress are below 9%. This work provides a methodology to assess cracking susceptibility and residual stress in actual Ti80 components by matching restraint conditions with Lehigh specimens. Full article

Despite extensive research on the effect of nitrogen flow rate on titanium nitride (TiN) coating properties, its influence on esthetic and engineering performance through microstructure control remains insufficiently explored. To simultaneously meet the requirements for surface strengthening and decorative esthetics in high-end stainless-steel crafts, TiN coatings were deposited on 304L stainless-steel substrates using multi-arc ion plating. The regulatory mechanisms and synergistic evolution laws of nitrogen flow rates (100, 200, and 300 sccm) on the microstructure, decorative properties (color and gloss), and engineering performance (adhesion strength, hardness, wear resistance, and corrosion resistance) of the coatings were investigated. At a nitrogen flow rate of 200 sccm, the coating exhibited a uniform and dense columnar crystal structure, as well as a saturated golden hue with high surface gloss. Additionally, the film–substrate adhesion, microhardness, tribological properties, and corrosion resistance reached optimal levels. In contrast, excessively low (100 sccm) or high (300 sccm) nitrogen flow rates resulted in coarse particles and blurred grain boundaries owing to uncontrolled droplet ejection or target poisoning, respectively, thereby deteriorating both appearance and engineering performance. These findings can inform the optimization of TiN coatings, enabling the design of surfaces that simultaneously meet esthetic and high-performance engineering requirements. Full article

Background: Mandibular defects caused by trauma or tumor resection pose significant challenges in both functional and aesthetic reconstruction. Additive manufacturing (AM) technologies offer promising solutions for surgical planning and personalized treatment. Objectives: This review aims to evaluate current trends in the application of AM technologies for mandibular resection and reconstruction, with a particular focus on material selection, clinical integration, and technology-specific advantages. Methods: A structured literature review was performed using PubMed, Scopus, Web of Science, and Google Scholar. Studies published between January 2020 and May 2025 were screened using the following inclusion criteria: original peer-reviewed English-language research involving AM in mandibular surgery. The exclusion criteria included review articles, non-English sources, and non-mandibular studies. A total of 77 studies met the inclusion criteria and were analyzed in this review. Results: Based on the literature review conducted from 2020 to 2025, the most common restorative methods for the mandible using additively manufactured models include reconstruction with a titanium surgical plate bent to the curvature of the edges and angle of the mandible or a personalized titanium or PEEK surgical plate made directly based on the patient’s diagnosis. Implants made of Ti-6AL-4V ELI and bioceramic scaffolds are also used in the reconstruction process. They are developed based on patient diagnostic data and effectively replace the loss of mandibular bone structure. In addition, based on models and surgical guides created using additive manufacturing techniques, the performance of autogenous grafts from the fibula or iliac crest has improved significantly when used with a titanium implant plate. Conclusions: Additive manufacturing supports highly personalized and accurate mandibular reconstruction. The advantages of these methods include a reduced overall duration of procedures, a lower health risk for patients due to less reliance on general anesthesia, a near perfect match between the implant and the remaining hard tissues, and satisfactory aesthetic outcomes. However, success depends on the appropriate selection AM technology and material, particularly in load-bearing applications. Full article

Metal nitride coatings have been considered as a promising approach to improve the performance of metal bipolar plates for proton exchange membrane fuel cells (PEMFCs). In this study, NbN_x coatings with three different ratios of N₂/Ar (1:2, 1:1 and 3:1) were prepared on TC4 alloy substrates using the double glow plasma alloying technology. The NbN_x coatings are homogeneous and dense, and the phase of the coating transforms from hexagonal β-Nb₂N to δ′-NbN phase as the nitrogen content increases. All coatings demonstrate high protective efficiency, with the coating (N₂/Ar ratio of 3:1) displaying the lowest current density of 8.92 × 10⁻⁶ A/cm² at a working voltage of 0.6 V. The EIS results also show that this coating has the best corrosion resistance. Notably, it also presents the lowest interfacial contact resistance of 7.29 mΩ·cm² at 1.5 MPa and good hydrophobicity. More importantly, this study provides a new idea and method for corrosion-resistant coatings of metal bipolar plates for PEMFC applications. Full article

This study investigates the application of the Keyhole–Tungsten Inert Gas Welding (K-TIG) hot-wire filling welding technique with mechanical arc oscillation to weld a 95 mm-thick Ti-6Al-4V titanium alloy plate. The root layer thickness achieved with this technique reaches up to 17 mm, with an average filling thickness of 2.5 mm. The weld bead displays a smooth, shiny appearance, and no significant welding defects are observed in the cross-section of the welded joint. Experimental results show that the welded joint consists of the α phase in different forms, as well as fine α+β microstructures. Compared to the base material, both the weld metal and the heat-affected zone exhibit a lower crystallographic texture strength, with more complex texture types. The impact toughness of the welded joint is excellent, with no significant weaknesses. The impact toughness of the weld metal significantly surpasses that of both the base material and the heat-affected zone. The engagement strengthening effect induced by high-current filling plays a crucial role in enhancing the impact toughness of the weld metal. Full article

This study investigates a novel approach based on micro-pulse plasma electrolytic oxidation (μPPEO), aiming to improve the control over key parameters such as the Ca/P ratio, the formation of anatase and rutile phases, and the porosity of titanium surfaces—factors that are critical for enhancing bioactivity. By employing electrical micro-pulses with widths of 50 μs or 100 μs, our aim was to restrict the discharge time and subsequent surface/electrolyte reactions. The results demonstrate that μPPEO-treated surfaces exhibit uniform pore diameters, a Ca/P ratio of approximately 1.67, and the better control of anatase/rutile formation. The μPPEO treatment successfully produced hydrophilic surfaces, with the 6Ti50 sample displaying the highest polar component of surface energy. Notably, this sample was the only one to support cell viability comparable to that of the polystyrene surface on the 24-well plate, emphasizing its strong potential for clinical applications. Across all treated surfaces, OFCOL osteoblasts displayed a spindle-like morphology with elongated filopodia, suggesting favorable cell interactions and adaptability to the treated surfaces. This study underscores the promise of PPEO as a valuable technique for biomedical applications, particularly in controlling and optimizing dental implant surfaces. Full article

Background/Objectives: Anterior cervical discectomy and fusion (ACDF) is a common procedure for treating cervical spondylotic myelopathy. Limited research exists on the predictors of subsidence following ACDF. Subsidence can compromise surgical outcomes, alter alignment, and predispose patients to further complications, making it essential to prevent and understand it. This study aims to identify key risk factors for clinically significant subsidence and evaluate its impact on cervical alignment parameters in a large, diverse patient population. Methods: We conducted a retrospective review of patients who underwent ACDF between 2013 and 2022 at a single institution. Subsidence was calculated as the mean change in anterior and posterior disc height, with clinically significant subsidence being defined as three millimeters or more. Univariate analysis was followed by regression modeling to identify subsidence predictors and analyze patterns. Subgroup analyses stratified patients by implant type, number of levels fused, and cage material. Results: A total of 96 patients with 141 levels of ACDF met the inclusion criteria. Patients with significant subsidence were younger on average (52.44 vs. 55.94 years; p = 0.074). Those with less postoperative lordosis were more likely to experience significant subsidence (79.5% vs. 90.2%; p = 0.088). Patients with significant subsidence were more likely to have standalone implants (38.5% vs. 16.7%; p < 0.01), taller cages (6.62 mm vs. 6.18 mm; p < 0.05), and greater loss of segmental lordosis (7.33 degrees vs. 3.31 degrees; p < 0.01). Multivariate analysis confirmed that standalone implants were a significant independent predictor of subsidence (OR 2.679; p < 0.05), and greater subsidence was positively associated with loss of segmental lordosis (OR 1.089; p < 0.01). Subgroup analysis revealed that multi-level procedures had a higher incidence of subsidence (35.7% vs. 28.1%; p = 0.156), and PEEK cages demonstrated similar subsidence rates compared to titanium constructs (28.1% vs. 29.4%; p = 0.897). Conclusions: Standalone implants are the strongest independent predictor of significant subsidence, and those that experience subsidence also show greater loss of segmental lordosis, although not overall lordosis. These findings have implications for surgical planning, particularly in patients with borderline bone quality or requiring multi-level fusions. The results support the use of plated constructs in high-risk patients and emphasize the importance of individualized surgical planning based on patient-specific factors. Further research is needed to explore these findings and determine how they can be applied to improve ACDF outcomes. Full article

A scalable synthesis of two-dimensional titanium nitride chloride (TiNCl) via flash Joule heating (FJH) using titanium tetrachloride (TiCl₄) precursor has been developed. This single-step method overcomes traditional synthesis challenges, including high energy consumption, multi-step procedures, and hazardous reagent requirements. The structural and chemical properties of the synthesized TiNCl were characterized through multiple analytical techniques. X-ray diffraction (XRD) patterns confirmed the presence of TiNCl phase, while Raman spectroscopy data showed no detectable oxide impurities. Fourier transform infrared spectroscopy (FTIR) analysis revealed characteristic Ti–N stretching vibrations, further confirming successful titanium nitride synthesis. Transmission electron microscopy (TEM) imaging revealed thin, plate-like nanostructures with high electron transparency. These analyses confirmed the formation of highly crystalline TiNCl flakes with nanoscale dimensions and minimal structural defects. The material exhibits excellent structural integrity and phase purity, demonstrating potential for applications in photocatalysis, electronics, and energy storage. This work establishes FJH as a sustainable and scalable approach for producing MXenes with controlled properties, facilitating their integration into emerging technologies. Unlike conventional methods, FJH enables rapid, energy-efficient synthesis while maintaining material quality, providing a viable route for industrial-scale production of two-dimensional materials. Full article

The titanium matrix composites (TMCs) fabricated via Directed Energy Deposition (DED) effectively overcome the issue of coarse columnar grains typically observed in additively manufactured titanium alloys. In this study, systematic annealing heat treatments were applied to in situ (TiB + TiC)/Ti-6Al-4V composites to refine the microstructure and tailor mechanical properties. The results reveal that the plate-like α phase in the as-deposited composites gradually transforms into an equiaxed morphology with increasing annealing temperature and holding time. Notably, when the annealing temperature exceeds 1000 °C, significant coarsening of the TiC phase is observed, while the TiB phase remains morphologically stable. Annealing promotes decomposition of acicular martensite and stress relaxation, leading to a reduction in hardness compared to the as-deposited state. However, the reticulated distribution of the TiB and TiC reinforcement phases contributes to enhanced tensile performance. Specifically, the as-deposited composite achieves a tensile strength of 1109 MPa in the XOY direction, representing a 21.6% improvement over the as-cast counterpart, while maintaining a ductility of 2.47%. These findings demonstrate that post-deposition annealing is an effective strategy to regulate microstructure and achieve a desirable balance between strength and ductility in DED-fabricated titanium matrix composites. Full article

Study design: The advent of the Matrix Wave^TM System (Depuy-Synthes)—a bone-anchored Mandibulo-Maxillary Fixation (MMF) System—merits closer consideration because of its peculiarities. Objective: This study alludes to two preliminary stages in the evolution of the Matrix Wave^TM MMF System and details its technical and functional features. Results: The Matrix Wave^TM System (MWS) is characterized by a smoothed square-shaped Titanium rod profile with a flexible undulating geometry distinct from the flat plate framework in Erich arch bars. Single MWS segments are Omega-shaped and carry a tie-up cleat for interarch linkage to the opposite jaw. The ends at the throughs of each MWS segment are equipped with threaded screw holes to receive locking screws for attachment to underlying mandibular or maxillary bone. An MWS can be partitioned into segments of various length from single Omega-shaped elements over incremental chains of interconnected units up to a horseshoe-shaped bracing of the dental arches. The sinus wave design of each segment allows for stretch, compression and torque movements. So, the entire MWS device can conform to distinctive spatial anatomic relationships. Displaced fragments can be reduced by in-situ-bending of the screw-fixated MWS/Omega segments to obtain accurate realignment of the jaw fragments for the best possible occlusion. Conclusion: The Matrix Wave^TM MMF System is an easy-to-apply modular MMF system that can be assembled according to individual demands. Its versatility allows to address most facial fracture scenarios in adults. The option of “omnidirectional” in-situ-bending provides a distinctive feature not found in alternate MMF solutions. Full article

Resistance spot welding was performed to join a 2 mm thick TA2 titanium plate and Q235 steel plate using nickel foil with thicknesses of 0.02 mm, 0.04 mm, and 0.06 mm as interlayers. The microstructure of the nugget zone and the interface region of the joint were systematically observed and analyzed, and the tensile shear-bearing capacity of the joint was evaluated. As the welding current increased, the tensile shear load of the joint exhibited a trend of initially increasing and subsequently decreasing. When the welding current was 8 kA, the tensile shear load of the joints with an interlayer of 0.04 mm thickness reached a maximum value of 8.02 kN. The results indicate that employing a reduced welding current can effectively prevent the mixing of nuggets on both sides of the titanium and steel interface. This ensures that the intermetallic compounds formed in the interface region are confined to the Ti-Ni series, which is crucial for enhancing the tensile shear load of the joint. Full article