In laser powder bed fusion (L-PBF), a metal powder–based additive manufacturing process, pure titanium powders rely on expensive gas-atomized spherical powders, which poses a significant limitation of material cost. In contrast, non-spherical titanium powders are more cost-effective but their application in L-PBF is restricted their use due to poor flow property and high oxygen content. In this study, a powder mixing strategy with spherical titanium and hydrophobic SiO2 nanoparticle is proposed to improve the flowability and process stability of non-spherical Ti powders. After evaluating flow properties at various mixing ratios, a spherical-to-non-spherical Ti ratio of 4:6 was selected, with SiO2 nanoparticles added during mixing. The uniform distribution of oxide nanoparticles on the powder surfaces was confirmed by SEM and EDS. A maximum relative density of 99.7% was shown by specimens made with L-PBF under various processing parameters. The specimens obtained a tensile strength of 762.6 ± 3.8 MPa and an elongation of 22.1 ± 0.7% at a volumetric energy density of 71.4 J/mm³. This study demonstrates the application of low-cost non-spherical Ti powders in L-PBF is feasible and presents an effective way to simultaneously increase process stability and economic efficiency in titanium additive manufacturing.

Ti.Grade12 is widely used in chemical processing, power generation, and nuclear industries because of its excellent corrosion resistance and mechanical strength, enhanced by alloying elements such as Ni and Mo. Ceramic reinforcements such as TiN have been reported to significantly improve the surface hardness and wear resistance of titanium-based materials. Furthermore, nano-sized WC particles can suppress excessive intermetallic compound formation and stabilize the Ti matrix through grain boundary pinning and microstructural control mechanisms. However, strong interfacial bonding between Ti and ceramic reinforcements generally requires high temperatures and prolonged sintering times, which may induce undesirable secondary phase formation. Therefore, optimizing the mixing ratio of Ti, TiN, and WC is essential to achieve a homogeneous interface and a stable composite structure. In this study, a composite layered structure was fabricated on a Ti.Grade12 substrate using mixed Ti, TiN, and nano-sized WC powders via Spark Plasma Sintering. A composition of 60 wt% Ti, 35 wt% TiN, and 5 wt% WC formed a stable coating layer without secondary phases and achieved a micro vickers hardness of approximately 2400 Hv.

Carbon fiber reinforced polymer (CFRP)/titanium alloy (Ti) stacks have become a research focus in aerospace and advanced manufacturing due to their superior integrated properties. However, interfacial characteristics and interlayer gaps critically influence cutting forces and hole-making quality. So, a cutting simulation model for CFRP/Ti stacks with interlayer gaps is established, the cutting force variation with interlayer gaps during milling and the mechanistic role in interfacial defect formation are deciphered through multiscale simulations. In addition, the correctness of the simulated model is verified by helical milling experiments, and the influence of machined surface quality under different clearance conditions is also evaluated. The results reveal a four-stage nonlinear evolution pattern of interfacial cutting forces during helical milling of CFRP/Ti stacks with gaps. Further investigation indicates that this nonlinear evolution pattern results in the development of localized damage evolution regions adjacent to interlayer gaps in CFRP composites, especially. A characteristic stepped distribution pattern is observed in both hole-wall topography and burr dimensions within the affected zones.

This study investigated the influence of alloying elements on the elastic modulus variation of titanium alloys and conducted theoretical density calculations, yielding the following conclusions. In Ti-M (M=Zr, Ag, Au, and Cu) alloys, the Md value ranges from 2.89325 to 11.1530, and the Bo value ranges from 2.30180 to 3.22978. Ti-Zr alloys are most suitable as optimal dental implant materials in terms of electronic structural stability and strength. Ti–Au and Ti–Ag primarily contribute to biocompatibility, corrosion resistance, and antibacterial performance, while offering less benefit for mechanical strengthening. Ti-Cu, while having low structural stability, exhibits excellent antibacterial functionality and is therefore worthy of consideration as a supplementary alloying element. The physical properties of ‑titanium–based Ti–M binary alloys have been examined, and future research will focus on extending the study to ternary and quaternary titanium alloy systems.

This study presents a cost-effective approach to fabricating near β-Ti alloys via in-situ alloying during laser powder bed fusion (L-PBF). A blend of non-spherical pure Ti, 3 wt.% Fe, and 0.1 wt.% SiO2 nanoparticles was used to induce β-phase stabilization and improve flowability. Twenty-five process conditions were evaluated across a volumetric energy density range of 31.75-214.30 J/mm3, achieving a maximum relative density of 99.21% at 89.29 J/mm3. X-ray diffraction analysis revealed that the β-Ti phase was partially retained at room temperature, accompanied by lattice contraction in the α’-Ti structure, indicating successful Fe incorporation. Elemental mapping confirmed that the Fe distribution was homogeneous, without significant segregation. Compared to pure Ti, the Ti-3Fe sample exhibited a 49.2% increase in Vickers hardness and notable improvements in yield and ultimate tensile strengths. These results demonstrate the feasibility of in-situ alloying with low-cost elemental powders to produce high-performance near β-Ti alloys using L-PBF.

This study investigated the effects of Fe and Cr contents on ω phase formation and transformation during solution treatment and the subsequent aging process, for which four model alloys with varying Fe and Cr contents but keeping Mo equivalent of ~ 12.6 were prepared by plasma arc melting and fabricated into plates by hot forging followed by hot-rolling. The atherrmal ω phase was observed in all Ti alloys after solution treatment followed by water quenching through XRD and TEM analysis. The largest volume fraction of athermal ω phase is formed in Ti alloy with only Fe 4 wt.% among all Ti alloys, leading to the highest Vickers value due to hardening effect ω phase. It was found that not only Mo equivalent but also each characteristic of β stabilizing elements should be considered to understand a microstructure evolution and mechanical properties.

Ti-6Al-4V alloy is widely utilized in aerospace and medical sectors due to its high specific strength, corrosion resistance, and biocompatibility. However, its low machinability makes it difficult to manufacture complex-shaped products. Advancements in additive manufacturing have focused on producing high-performance, complex components using the laser powder bed fusion (LPBF) process, which is a specialized technique for customized geometries. The LPBF process exposes materials to extreme thermal conditions and rapid cooling rates, leading to residual stresses within the parts. These stresses are intensified by variations in the thermal history across regions of the component. These variations result in differences in microstructure and mechanical properties, causing distortion. Although support structure design has been researched to minimize residual stress, few studies have conducted quantitative analyses of stress variations due to different support designs. This study investigated changes in the residual stress and mechanical properties of Ti-6Al-4V alloy fabricated using LPBF, focusing on support structure design.

LTO is a commercial anode material that contributes to delivered energy and cycle stability. With affordability and high energy density, graphite faces limited cycle time and inferior stability. Here, we discussed the LTO challenges and compared the Ti-based anode from the original structure to the LTO-MXene composites, which are promising alternative anodes. Spinel lithium titanate (LTO) possesses high working voltage, stability, safety, and negligible volume change, while it suffers from low electronic conductivity that limits rate performance at large current densities. 2D Mxenes have recently drawn attention to various applications due to high conductivity, large surface area, flexibility, and polar surface benefits. We critically reviewed the synthesis approaches, morphology views, and electrochemical behavior of LTO-MXene as new anode materials in lithium-ion batteries (LIBs). There are few reports on LTO-MXene anodes in LIBs. They provide a synergistic action of LTO and MXene, enhancing the accessibility of electrolytes and reducing the distance, benefiting fast diffusion. This review paper sheds light on how the synthesis approaches can directly affect LIB configurations' durability and energy density and lead researchers to develop features of LTO anodes with promising engagement.

Piezoelectric composites have attracted significant research interest as sustainable power sources for electronic devices due to their high mechanical stability and electrical output characteristics. This study investigated the optimal processing conditions for fabricating a flexible piezoelectric energy harvester based on Pb(Zr,Ti)O3 (PZT) powder and a polyimide (PI) matrix composite. Various parameters, including the optimal mixing ratio of PI/PZT, ultrasonic treatment, homogenization, vacuum oven, and UV/O3 treatment, were optimized to achieve a uniform piezoelectric composite. A PZT content of 30 wt% and 20 minutes of homogenization were identified as the most effective conditions for increasing the uniformity of the composite. The optimized composite exhibited a high piezoelectric coefficient, a typical P-E hysteresis loop, and dielectric properties, exhibiting a voltage output that adjusts in response to variations in the applied touch force. This study provides foundational data for the uniform fabrication of flexible piezoelectric energy harvesters and next-generation miniaturized electronic devices.

Super-duplex stainless steels are in great demand in various industrial fields such as chemical processing and seawater desalination due to their excellent pitting corrosion resistance. However, detrimental phases can easily form during fabrication, and even minor additions of alloying elements can significantly impact their microstructure and properties. This study investigated the effects Cu or Ti additions on a super-duplex stainless steel. First, the effects of annealing time at 950 °C on the microstructure and corrosion characteristics were investigated. It was found that as the annealing time increased, the fraction of sigma phase increased; however, the corrosion resistance in the electrochemical test using a 3.5 % NaCl electrolyte showed only a slight improvement. The microstructure of duplex stainless steel with added Cu or Ti did not differ significantly from that of the base steel. However, the overall corrosion resistance showed improvement, and in particular, an observed increase in pitting potential. Investigating the characteristics of the passive film on the alloy surface revealed that the stability of the passive film was higher in alloys with added Cu or Ti compared to the standard alloy. Among these, the alloy with Cu addition had the thickest film, while the Ti-added alloy had the highest Cr concentration and a film thickness greater than that of the standard alloy.

Mo-ODS alloys have excellent mechanical properties, including an improved recrystallization temperature, greater strength due to dispersed oxides, and the ability to suppress grain growth at high temperatures. In ODS alloys, the dispersed Y2O3 and added Ti form Y-Ti-O complex oxides, producing finer particles than those in the initial Y2O3. The complex oxides increase high-temperature stability and improve the mechanical properties of the alloy. In particular, the use of TiH2 powder, which is more brittle than conventional Ti, can enable the distribution of finer oxides than is possible with conventional Ti powder during milling. Moreover, dehydrogenation leads to a more refined powder size in the reduction process. This study investigated the refinement of Yi2Ti2O7 in a nano Mo-ODS alloy using TiH2. The alloy compositions were determined to be Mo-0.5Ti-0.5Yi2O3 and Mo-1.0Ti-0.5Yi2Oi2. The nano Mo-ODS alloys were fabricated using Ti and TiH2 to explore the effects of adding different forms of Ti. The sintered specimens were analyzed through X-ray diffraction for phase analysis, and the microstructure of the alloys was analyzed using scanning electron microscopy and transmission electron microscopy. Vickers hardness tests were conducted to determine the effect of the form of Ti added on the mechanical properties, and it was found that using TiHi2 effectively improved the mechanical properties.

This review examines the microstructural and mechanical properties of a Ti-6Al-4V alloy produced by wrought processing and powder metallurgy (PM), specifically laser powder bed fusion (LPBF) and hot isostatic pressing. Wrought methods, such as forging and rolling, create equiaxed alpha (α) and beta (β) grain structures with balanced properties, which are ideal for fatigue resistance. In contrast, PM methods, particularly LPBF, often yield a martensitic α′ structure with high microhardness, enabling complex geometries but requiring post-processing to improve its properties and reduce stress. The study evaluated the effects of processing parameters on grain size, phase distribution, and material characteristics, guiding the choice of fabrication techniques for optimizing Ti-6Al-4V performance in aerospace, biomedical, and automotive applications. The analysis emphasizes tailored processing to meet advanced engineering demands.

This study analyzed the influence of ball size and process control agents on the refinement and dehydrogenation behavior of TiH2 powder. Powders milled using ZrO2 balls with diameters of 0.1 mm, 0.3 mm, and 0.3+0.5+1 mm exhibited a bimodal particle size distribution, of which the first mode had the smallest size of 0.23 μm for the 0.3 mm balls. Using ethanol and/or stearic acid as process control agents was effective in particle refinement. Thermogravimetric analysis showed that dehydrogenation of the milled powder started at a relatively low temperature compared to the raw powder, which is interpreted to have resulted from a decrease in particle size and an increase in defects. The dehydrogenation kinetics of the TiH2 powder were evaluated by the magnitude of peak shift with heating rates using thermogravimetric analysis. The activation energy of the dehydrogenation reaction, calculated from the slope of the Kissinger plot, was measured to be 228.6 kJ/mol for the raw powder and 194.5 kJ/mol for the milled powder. TEM analysis revealed that both the milled and dehydrogenated powders showed an angular shape with a size of about 200 nm.

This study explored the process-structure-property (PSP) relationships in Ti-6Al-4V alloys fabricated through direct energy deposition (DED) additive manufacturing. A systematic investigation was conducted to clarify how process variables—specifically, manipulating the cooling rate and energy input by adjusting the laser power and scan speed during the DED process—influenced the phase fractions, pore structures, and the resultant mechanical properties of the samples under various processing conditions. Significant links were found between the controlled process parameters and the structural and mechanical characteristics of the produced alloys. The findings of this research provide foundational knowledge that will drive the development of more effective and precise control strategies in additive manufacturing, thereby improving the performance and reliability of produced materials. This, in turn, promises to make significant contributions to both the advancement of additive manufacturing technologies and their applications in critical sectors.

La modified lead zirconate titanate ceramics (Pb0.92La0.08)(Zr0.95Ti0.05)O3 = PLZT-8/95/5 were prepared using the conventional solid state reaction method in order to investigate the complex impedance characteristics of the PLZT-8/95/5 ceramic according to temperature. The complex impedance in the PLZT-8/95/5 ceramic was measured over a temperature range of 30~550 °C at several frequencies. The complex dielectric constant anomaly of the phase transition was observed near TU1 = 179 °C and TU2 = 230 °C. A remarkable diffuse dielectric constant anomalous behaviour of the complex dielectric constant was found between 100 °C and 550 °C. The complex impedance spectra below and above TU1 and TU2 were fitted by the superposition of two Cole-Cole types of impedance relaxations. The fast component in the higher frequency region may be due to ion migration in the bulk, and the slow component in the lower frequency region is interpreted to be the formation and migration of ions at the grain boundary or electrode/crystal interfacial polarization.

Accurate and rapid detection of antibiotics is critical for protecting human health and the environment. To this end, we report a novel electrochemical sensor for the simultaneous detection of Levofloxacin (LFX) and Tryptophan (TRP) in dairy samples. Outstanding electrocatalytic activity for the oxidation of LFX and TRP is exhibited by the Activated Nanodiamond (AND) and Ti3AlC2 max phase ( Ti3AlC2max) nanocomposite-modified glassy carbon electrode ( Ti3AlC2max AND/GCE) featured in our sensor. High selectivity and sensitivity are achieved by the sensor, with limits of detection (LOD) of 20.47 nM and 0.309 μM for LFX and TRP, respectively. Moreover, strong anti-parasite capacity is demonstrated by the developed sensor, making it an excellent candidate for the establishment of a reliable sensing platform for antibiotic detection. Findings suggest that this novel sensor could serve as a valuable tool for monitoring the content of LFX and TRP in dairy samples and enhancing the safety of these products.

본 실험에서는 Ti를 기반으로 한 평판 수소 분리막을 설계하여 제조하였다. 새로운 조성의 Ti를 베이스로 한 수소 분 리막을 찾기 위하여 여러 합금들의 물리화학적 특성과 수소투과도 사이의 상관관계에 대해 조사하였다. 이를 바탕으로 신조성의 합금막 2종(Ti14.2Zr66.4Ni12.6Cu6.8 (70 μm), Ti17.3Zr62.7Ni20 (80 μm))을 설계 및 제조하였다. 제조된 평판 수소 분리막은 300~500°C, 1~4 bar의 조건에서 혼합 가스(H2, N2), sweep 가스(Ar)를 이용하여 수소 투과 실험을 진행하였다. Ti14.2Zr66.4Ni12.6Cu6.8 합금 막은 500°C, 4bar에서 최대 16.35 mL/cm2min의 flux를 가지며, Ti17.3Zr62.7Ni20 합금막은 450°C, 4 bar에서 최대 10.28 mL/ cm2min의 flux를 가진다.

In order to predict the process window of laser powder bed fusion (LPBF) for printing metallic components, the calculation of volumetric energy density (VED) has been widely calculated for controlling process parameters. However, because it is assumed that the process parameters contribute equally to heat input, the VED still has limitation for predicting the process window of LPBF-processed materials. In this study, an explainable machine learning (xML) approach was adopted to predict and understand the contribution of each process parameter to defect evolution in Ti alloys in the LPBF process. Various ML models were trained, and the Shapley additive explanation method was adopted to quantify the importance of each process parameter. This study can offer effective guidelines for fine-tuning process parameters to fabricate high-quality products using LPBF.

In this study, a core-shell powder and sintered specimens using a mechanically alloyed (MAed) Ti-Mo powder fabricated through high-energy ball-milling are prepared. Analysis of sintering, microstructure, and mechanical properties confirms the applicability of the powder as a sputtering target material. To optimize the MAed Ti-Mo powder milling process, phase and elemental analyses of the powders are performed according to milling time. The results reveal that 20 h of milling time is the most suitable for the manufacturing process. Subsequently, the MAed Ti-Mo powder and MoO3 powder are milled using a 3-D mixer and heat-treated for hydrogen reduction to manufacture the core-shell powder. The reduced core-shell powder is transformed to sintered specimens through molding and sintering at 1300 and 1400oC. The sintering properties are analyzed through X-ray diffraction and scanning electron microscopy for phase and porosity analyses. Moreover, the microstructure of the powder is investigated through optical microscopy and electron probe microstructure analysis. The Ti-Mo core-shell sintered specimen is found to possess high density, uniform microstructure, and excellent hardness properties. These results indicate that the Ti-Mo core-shell sintered specimen has excellent sintering properties and is suitable as a sputtering target material.

The aerospace and power generation industries have an increasing demand for high-temperature, highstrength materials. However, conventional materials typically lack sufficient fracture toughness and oxidation resistance at high temperatures. This study aims to enhance the high-temperature properties of Nb-Si-Ti alloys through ball milling. To analyze the effects of milling time, the progression of alloying is evaluated on the basis of XRD patterns and the microstructure of alloy powders. Spark plasma sintering (SPS) is employed to produce compacts, with thermodynamic modeling assisting in predicting phase fractions and sintering temperature ranges. The changes in the microstructure and variation in the mechanical properties due to the adjustment of the sintering temperature provide insights into the influence of Nb solid solution, Nb5Si3, and crystallite size within the compacts. By investigating the changes in the mechanical properties through strengthening mechanisms, such as precipitation strengthening, solid solution strengthening, and crystallite refinement, this study aims to verify the applicability of Nb-Si-Ti alloys in advanced material systems.