Enophthalmos is a severe complication of primary reconstruction following orbital floor frac-tures, oncological resections or maxillo-facial syndromes. The goal of secondary reconstruction is to re-store symmetrical globe positions to recover function and aesthetics. In this article we pre-sent a method of computer-assisted orbital floor reconstruction using a mirroring technique and a customized titanium or high-density polyethylene mesh, printed using computer aided manufac-turing techniques. This reconstructive protocol involves 4 steps: mirroring of the healthy orbit at the affected site, vir-tual design of a patient specific orbital floor mesh, computer-assisted manufacturing (CAD) of the implant, and surgical insertion of the device. Using a computed tomography data set, the un-injured side of the craniofacial skeleton was reflected onto the contralateral injured side, and a reconstructive orbital floor prosthesis was virtually designed on the mirrored orbital bone sur-face. The solid-to-layer (.STL) files of the prosthesis were then manufactured using Direct Metal Laser Sintering (DMLS) or Computer Numerical Control (CNC) methods, leading to the produc-tion of 10 titanium meshes and 2 high density polyethylene (HDPE) implants. Clinical outcomes were assessed using 3dMD photogrammetry and computed tomography measures in 14 treated patients. The technique described here appears to be a viable method to correct complex orbital floor de-fects needing delayed reconstruction. This article represents the prosecution of a previous study, which is part of a wider experimental protocol for orbital floor reconstruction using comput-er-assisted design-computer-assisted manufacturing (CAD-CAM) technology

This paper presents a new method of preparing a coating on the Ti65 titanium alloy by a two-step procedure comprising hot-dipped aluminum and solid carburization. The effects of the carburization in the presence of NaCl deposit at 810oC have been systematically studied. In this article, the microstructure, morphology, phase composition of the coating, and the corrosion products were investigated by SEM, EDS, and X-ray diffraction. Results indicated that the corrosion resistance of hot dip aluminum/carburizing composite coating was not significantly enhanced by hot dip aluminum coating. This can be attributed to the formation of TiC and Ti3AlC after carburization, which promoted the formation of loose and unprotected TiO2 in the coating during molten salt corrosion. In addition, the oxidation of the carbon atom into CO2 /CO leaded to a high concentration of vacancy in the coating, creating channels for NaCl to penetrate the coating and accelerated the corrosion rate.

Strontium (Sr) is a trace element in human body that able to promote bone formation and inhibit bone absorption. The conversion coating of strontium phosphate (Sr-P) on the surface of titanium (Ti) can improve its biological properties, and has a wide application prospect in the fields of dentistry and orthopedics. In this present study, Sr-P coatings with SrHPO4 and Sr3(PO4)2 crystals on Ti are prepared by phosphate chemical conversion (PCC) treatment. And the effect of pH on the properties of Sr-P coatings is researched. The results prove that phase composition, morphology and corrosion resistance of coated Ti are different with the pH values in PCC solution. The morphologies of conversion deposition on Ti change from plat-like to cluster-like, and then homogeneous microcrystals, as pH value changed from 2.50 to 3.25. Only discrete SrHPO4 crystals are generating on substrate at lower pH value, while relative stable Sr3(PO4)2 and SrHPO4 crystals are growing and subsequently forming an integrated coating on Ti as pH is higher than 2.50. The corrosion resistance of coated Ti improves comparing with that of bare Ti because of forming Sr-P coatings with Sr3(PO4)2 phase. In addition, it is indicated that the Sr-P coatings can improve the adhesion and differentiation of BMSCs.

The use of miniplates for stabilizing bones after orthognathic surgeries, has become increasingly popular for their effectiveness in ensuring stability and promoting swift recovery. However, the post-surgical fate of these miniplates remains a subject of contention among surgeons. Some advocate for their removal, while others suggest leaving them in place. The aims of this study, is to evaluate the incidence, causes, and potential risk factors associated with the removal of miniplates in orthognathic surgeries. A comprehensive meta-analysis was conducted by reviewing studies from various databases like PubMed, Google Scholar, Research Gate, Embase, and Scopus, focusing on publications from 1989 to 2023. Ten studies encompassing a total of 1603 patients which conformed to the inclusion criteria were selected and included in the meta-analysis. With M:F ratio range from 4:1 to 109:141. Total number of miniplates inserted was 5595, and total number of miniplates removed were 294 (5.3%). The most common reasons for miniplates removal were, infection was reported in 161 cases (2.9%), followed by miniplates exposure (34 cases, 0.6%) and palpable plates (23 cases 0.4%). Other indications included pain, patient’s preference, and temperature sensitivity. Relatively less common reasons that resulted in miniplates removal include, sinusitis, second surgery and dental pathology. The mean duration of miniplates removal was 5.5 months with the majority of miniplates (56.1%) were removed from the mandible compared to maxilla. In conclusion, this meta-analysis underscores the importance of miniplate removal in cases where hardware causes diverse complications and physical discomfort. The primary reasons for miniplates removal were infections and plates exposure, with the mandible being the most common site for removal. These findings emphasize the need for continued monitoring to assess the fate of miniplates in orthognathic surgery and provide valuable insights for future clinical decision-making.

In this work, nanocomposite photoelectrodes of the TiO2/ Au composition were manufactured, in which the size of plasmonic Au nanoparticles was varied, and the morphology of the TiO2 layer, depending on the thickness, changed from an island to a continuous layer. The influence of the morphology of plasmonic Au nanoparticles and the TiO2 layer on the optical and photoelectrochemical characteristics of hybrid photoelectrodes was studied. It has been shown that continuous coating of Au nanoparticles with a TiO2 layer (layer thickness 10 and 15 nm) leads to a decrease in the photoelectric response, and the decrease in photocurrent density and photoconversion efficiency decreases in proportion to the thickness of the TiO2 layer. The indicated drop in characteristics when plasmonic particles are located under the TiO2 layer is presumably associated with the scattering and recombination of charge carriers in the semiconductor layer. The best performance was shown by a system in which large Au nanoparticles (10 nm) are coated with a 5 nm thick layer of titanium dioxide; in this geometry, Au nanoparticles are decorated with TiO2 nanoparticles, as a result of which the photoelectrode-electrolyte interface has a more complex structure.

Ti-Al alloy phase layer/Ti-Al carburizing composite coating was prepared on the surface of titanium alloy by the stepwise coating method of hot dip aluminization and then carburizing. The weight gain results of the composite coating showed that the titanium alloy coated with the composite coating had long-term stability (≥16 days) at 800oC. The microstructure, phase structure and composition of the composite coating were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).The composite coating is composed of an alloy phase layer and a carburized layer. The natural transition of four phases (Ti3Al/TiAl/TiAl2/TiAl3) in the alloy phase layer, significantly improves the interfacial bonding between the coating and the substrate, and slows down the propagation of microcracks through the coating.Al2O3, TiC and C in the carburizing layer improve the surface hardness of the coating, and TiAl2 and Al2O3 also have excellent oxidation resistance at high temperature.

Titanium middle ear prostheses are widely used in surgical practice due to their acoustic properties. However, they present a significant drawback shared by all synthetic materials currently in use for middle ear reconstruction: they can be rejected by the organism of the host. In this study, we aim to review the current literature on titanium TORP and PORP extrusion and dislocation. Eighty-one articles were analysed after full article review based on the inclusion and exclusion criteria. The most common indication for reconstruction was chronic otitis media with cholesteatoma. The average extrusion or dislocation rate was 5.1%, ranging from 0 to 35%. The average improvement in air-bone gap was 12.3 dB (1.6 dB to 25.1 dB) and 13.7 (-0,5 dB to 22.7 dB) for PORP ad TORP groups, respectively. The data reported on this topic are highly variable, demonstrating the functional outcomes are difficult to predict in clinical practice. We believe the current limitations could be overcome with technological developments, including bioengineering research focused on promoting the prothesis adaptation to the ME environment.

High temperature titanium alloys are widely used in aerospace hot parts, however, the thermal barrier temperature of 600 oC limits its service temperature. In this paper, a two-step hot-dip plating method is proposed to prepare the composite coating containing Ce on the surface of titanium alloy, which can make the oxidation resistance temperature of titanium alloy reach 800 oC The microstructure, phase composition and element distribution of Ce-containing Ti-Al-Si hot-dip coating, Ce-containing Ti-Al-Si pre-oxidation coating and Ce-containing Ti-Al-Si high-temperature oxidation coating were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The results show that the Ti-Al-Si hot-dip coating containing Ce is mainly composed of (Ti,Ce)(Al,Si)3 alloy phase layer, and the Ti-Al-Si pre-oxidation coating containing Ce is mainly composed of Ti-Al binary system phase layer and dense Al2O3 layer rich in CeO2. Ce in the high temperature oxidation coating of Ti-Al-Si containing Ce is mainly distributed in Ti3Al, TiAl, TiAl3+Ti5Si3 mixed phase layer and Al2O3. The addition of Ce can promote the formation of continuous Al2O3 layer, improve the uniformity of composite coating, prevent the spread of cracks, and improve the high temperature oxidation resistance of Ti-Al-Si coating.

Due to the high specific surface area of titanium aluminide powders, significant and unavoidable surface oxidation takes place during processing. The resulting oxides disrupt the conventional powder metallurgical process route (pressing and sintering) by reducing green strength and sintered properties. Oxide-free particle surfaces offer the potential to significantly increase particle bond strength and enable the processing of difficult-to-press material powders. In this work, the effect of milling titanium aluminide powder in a silane-doped atmosphere on the component properties after pressing and subsequent sintering was investigated. Ball milling was used to break up the oxide layers and create bare metal surfaces on the particles. With the help of silane-doped inert gas, the oxygen partial pressure was greatly reduced during machining. It was investigated whether oxide-free surfaces could be produced and maintained by milling in silane-doped at-mospheres. Furthermore, the resulting material properties after pressing and sintering were an-alyzed using density measurements, hardness tests, EDX-measurements and micrographs. It was concluded, that ball milling in a silane-doped atmosphere produces and maintains oxide-free particle surfaces. These oxide-free surfaces and smaller particle sizes improve the component properties after pressing and sintering.

At present, in the field of aviation industry, titanium alloy is mainly used to manufacture parts such as compressor disc, blade and casing of aircraft engine. When working, titanium alloy parts produce high temperature due to high-speed running friction, which makes the high temperature oxidation resistance and friction resistance of titanium alloy greatly reduced. When their working environment contains salt, titanium alloys are subjected to thermal corrosion, which limits their wider practical applications. This paper introduce the aluminide coating and its preparation methods. The characteristics and functional mechanism of three functional coatings for service environment, such as high temperature resistant alumina-based coating, thermal corrosion resistant alumina-based coating and wear-resistant alumina-based coating are summarized. Finally, the development direction of composite coatings of titanium and titanium alloys for complex service environment is prospected.

Directed energy deposition (DED) parameters were determined for near-β alloy Ti-55511 by employing statistical design of experiments (DOE) methods. Parameters resulting in fully dense freeform deposits were identified using two sequential DOEs. Single laser tracks were printed with several laser power, traverse rate, and powder feed rate settings in an initial DOE to identify promising build parameters. Capture efficiency and effective deposition rate were used to characterize and rank the single track deposits. The best parameters were then used to print solid cube with various X-Y and Z-overlaps (different hatch spacing, HS, and layer thickness, ZS) in a second DOE. Suitable deposition parameters were selected based on cube density and microstructure and were used to fabricate larger tensile samples for mechanical testing. Multiple parameter sets were found to provide dense Ti-55511 deposits with acceptable mechanical properties and parametric models showed statistical significance.

Bioactive surface coatings have retained the attention of researchers and physicians due to their versatility and range of applications in orthopedics, particularly in infection prevention. Antibacterial metal nanoparticles (mNPs) are a promising therapeutic, with vast application opportunities on orthopedic implants. The current research aimed to construct a polyelectrolyte multilayer on a highly porous titanium implant using alternating thin film coatings of chitosan and alginate via the layer-by-layer (LbL) self-assembly technique, along with the incorporation of silver nanoparticles (AgNPs) or titanium dioxide nanoparticles (TiO2NPs), for antibacterial and osteoconductive activity. These mNPs were characterized for their physicochemical properties using quartz crystal microgravimetry with dissipation system, nanoparticle tracking analysis, scanning electron microscopy, and atomic force microscopy. Their cytotoxicity and osteogenic differentiation capabilities were assessed by AlamarBlue and alkaline phosphatase (ALP) activity assays, respectively. The antibiofilm efficacy of the mNPs tested against Staphylococcus aureus. The LbL polyelectrolyte coating was successfully applied to the porous titanium substrate. A dose-dependent relationship between nanoparticle concentration and ALP as well as antibacterial effects was observed. TiO2NP samples were also less cytotoxic than AgNP counterparts, although similarly antimicrobial. Together, these data serve as a proof-of-concept for a novel coating approach for orthopedic implants with antimicrobial and osteoconductive properties.

The current work shows the optimization in the preparation of nanosized titanium carbide (TiC) in-situ through mechanical alloying (MA). Metallic titanium (Ti) powders, along with two carbon sources, carbon nanotubes (CNTs), and stearic acid (SA), were used to reduce the particle size using a high-energy Spex800 mill. The combined use of 2 wt % of these carbon sources and n-heptane as a liquid process control agent (PCA) proved crucial in generating nanoscale powder composites through a simple and scalable synthesis process within a 4-hour timeframe. The use of 20 wt % of both carbon sources was compared to determine the ability of CNTs to form carbides and the decomposition of PCAs during mechanical milling. The result reveals structures like nanoblocks and nanolumps with and important size reduction. The structure and morphology of the composites and starting materials were evaluated through x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Magnetron sputtering was used for producing Titanium Vanadium Nitride (TiVN) coatings on a variety of substrates. In this research, we investigate how changing the sputtering power and nitrogen: argon (N2:Ar) gas ratio affects the structural and tribological properties of TiVN coatings. Scanning Electron Microscope (SEM) technique was used to examine TiVN coating surface morphology. Both variants showed a gradual increase in the intensity of the TiVN coating's (111) and (222) peaks. TiVN coating's tribological properties were examined using a pin-on-disc tribometer with varying loads, speeds, and sliding distances. The wear rates of TiVN-coated brass pins were in the range of 2.5×10-4 to 9.14×10-4 mm3/Nm depending on load, sliding distance, and gas ratio variation, when compared to the wear rates of TiVN-coated brass pins deposited at various power, which ranged from 1.76×10-3 to 5.87×10-3 mm3/Nm.

Ultra-low radioactive titanium alloy is a promising material for the manufacture of low-background detectors, which are being developed for experiments in astroparticle physics and neutrino astrophysics. Structural titanium is manufactured on an industrial scale from titanium-sponge. The ultra-low-background titanium-sponge can be produced on an industrial scale with a contamination level of less than 1 mBq/kg of uranium and thorium isotopes. The pathways of contaminants during the industrial production of structural titanium have been analyzed. The measurements have been carried out using two methods: inductively coupled plasma spectroscopy (ICP-MS) and gamma-spectroscopy using high-purity germanium detectors (HPGe). It has been shown that the level of contamination with radioactive impurities does not increase during remelting of titanium-sponge and mechanical processing. We examined titanium-alloys samples obtained at different stages of titanium production, namely, an electrode compaction, a vacuum arc remelting with a consumable electrode (VAR), and a cold rolling of titanium-sheets. It has been found out that all studied samples will be a source of uranium and thorium contamination of the final titanium-alloys. It has been established that the only product allowed obtaining ultra-low-background titanium was the VT1-00 which is manufactured without master alloys addition..

The majority of contemporary total hip arthroplasty (THA) implants are constructed from Ti-alloys, which are generally believed to generate fewer adverse local tissue reactions (ALTR) compared to CoCr-alloys. This study presents a case of unusual primary THA failure where a substantial release of Ti-alloy debris was observed. A 52-year-old active male underwent THA after posttraumatic aseptic necrosis of the femoral head in 2006. Seventeen years after the procedure, the patient presented with groin pain and restricted range of motion. X-rays revealed protrusion of the alumina ceramic head through the Ti6Al4V acetabular cup. Trace element analysis indicated significantly elevated levels of serum Ti, Al and V. CT and MRI confirmed Ti-alloy cup failure and severe ALTR. During revision surgery, the worn-out ceramic head was in direct contact with the acetabular cup, having protruded through the central hole it created over time. Histological analysis of tissue samples showed wear-induced synovitis with areas of multinucleated foreign-body giant cells and accumulation of numerous metal particles but no acute inflammatory response. Six months after the revision THA, the patient has experienced favourable outcomes. This case provides an instructive illustration for studying the consequences of substantial release of Ti-alloy debris from orthopaedic implants.

Two antimicrobial agents such as silver nanoparticles (AgNPs) and titanium dioxide (TiO2) have been formulated with natural polysaccharides (chitosan or alginate) to develop innovative inks for the rapid, customizable, and extremely accurate manufacturing of 3D printed scaffolds useful as dressings in the treatment of infected skin wounds. Suitable chemical-physical properties for the applicability of these innovative devices were demonstrated through the evaluation of water content (88-93%), mechanical strength (Young’s modulus 0.23-0.6 MPa), elasticity, and morphology. The antimicrobial tests performed against Staphylococcus Aureus and Pseudomonas Aeruginosa demonstrated the antimicrobial activities against Gram+ and Gram– bacteria of AgNPs and TiO2 agents embedded in the CH or ALG macroporous 3D hydrogels (AgNPs MIC starting from 5 µg/ml). The biocompatibility of chitosan was widely demonstrated by cell viability tests and was higher than that observed for alginate. Constructs containing AgNPs at 10 µg/ml concentration level did not significantly alter cell viability as well as the presence of titanium dioxide; cytotoxicity towards human fibroblasts was observed starting with AgNPs concentration of 100 µg/ml. In conclusions, the 3D printed dressings here developed own the features to be cheap, highly defined, easy to be manufactured and further applied in personalized antimicrobial medicine applications.

Density functional theory (DFT) calculations of hydrogen adsorption on titanium nitride had previously shown that hydrogen may adsorb on both titanium and nitrogen sites with a moderate adsorption energy. Further, the diffusion barrier was also found to be low. These findings may qualify TiN, a versatile multifunctional material with electronic conductivity, as electrode material for the hydrogen evolution reaction (HER). This was the main impetus of this work which aims to experimentally and theoretically investigate the electrocatalytic properties of TiN-layers that were processed on Ti substrate using reactive ion sputtering. The properties are discussed focusing on the role of oxygen defects introduced during the sputtering process on the HER. Based on DFT calculations, it is shown that these oxygen defects alter the electronic environment of the Ti atoms which entails a low hydrogen adsorption energy in the range of -0.1 eV; this leads to HER performances that match those of Pt-NPs in acidic media. When a few nanometr thick layer of Pd-NPs is sputtered on-top of the TiN-layer, the performance is drastically reduced. This is interpreted in terms of oxygen defects being scavenged by the Pd-NPs near the surface which is thought to reduce the hydrogen adsorption sites.

Lewis acid zeolites play an important role in industrially important green reactions closely related to fine chemicals and biomass conversion. Titanium-doped TS-1 zeolite is a milestone Lewis acid zeolite, which widely uses in industrially significant green oxidation processes with hydrogen peroxide as an oxidant under mild conditions. TS-1 Zeolites are normally synthesized in basic condition under hydrothermal treatment. Up to now, it is still not successful to synthesize active TS-1 Lewis acid zeolite by using inorganic alkali, e.g. NaOH or KOH as base, which are cheaper and more stable compared with quaternary ammonium hydroxide or organic amines used in the traditional synthesis. Here, inorganic base of NaOH was firstly employed in synthesizing active TS-1 zeolites. The crucial factor was the control of adverse effects of sodium cations on the incorporation of active titanium cations. A higher catalytic activity could be achieved by further reducing the size of the TS-1 crystal by seed-added strategy, which could approach the catalytic activity of commercial catalyst while the production cost was much lower than the commercial TS-1 catalysts, indicating great commercial potential and the possibility of preparing other cheap Lewis acid catalysts by using inorganic alkali.

Micro-arc oxidation (MAO) is an emerging technology employed to produce high hardness or anti-corrosion ceramic coatings on lightweight metals such Al, Ti, Mg and their respective alloys. However, under non-lubrication conditions, such coatings exhibit relatively high friction coeffi-cients. To enhance the friction reduction properties of the MAO coatings, we employed a one-step MAO process with varying concentrations of graphene oxide (GO) in an aluminate sys-tem electrolyte to create composite coatings on the surfaces of Ti-6Al-4V alloy. The effect of concentrations of GO particles on microstructure, composition, and wear behavior of the result-ing composite coatings was investigated. Measurements of the coating's thickness, hardness, and roughness have also been conducted. Ball-on-disk friction test under dry condition were carried out to reveal tribological behavior of the MAO coating. The addition of graphene oxide in the electrolyte reduces the friction coefficient, with the composite coating containing 5 g/L of GO particles displaying the most effective friction reduction. Moreover, coating thickness increases with higher GO concentration. This friction reduction can be attributed to the particles in the coating acting as lubricants during friction, while GO also reduces adhesive damage, shifting the wear mechanism from adhesive to abrasive.

In this article, copper(II) oxide, titanium dioxide and yttrium(III) oxide nanoparticles were added to Group III type base oil formulated with overbased calcium sulfonate. The nano-sized oxides were treated with ethyl oleate surface modification. The tribological properties of the homogenized oil samples were tested on a linear oscillating tribometer. Friction was continuously monitored during the tribological tests. Surface analysis was performed on the worn samples: the amount of wear was determined using a digital optical and confocal microscope. The type of wear was examined with a scanning electron microscope, while the additives adhered to the surface were examined with energy-dispersive X-ray spectroscopy. From the results of the measurements, it can be concluded that the surface-modified nanoparticles worked well with the overbased calcium sulfonate and significantly reduced both wear and friction. In the present tribology system, the optimal concentration of all three oxide ceramic nanoadditives is 0.4 wt%. By using oxide nanoparticles, friction can be reduced by up to 15% and the wear volume by up to 77%. Overbased calcium sulfonate and oxide ceramic nanoparticles together form a lower friction anti-wear boundary layer on the worn surfaces. It is advisable to further investigate the possibility of formulating nanoparticles into the oil.

The possibility of increasing wear resistance of the CP-Ti surface using a duplex surface treat-ment combining plasma electrolytic nitrocarburizing in a solution of ammonia, acetone and ammonium chloride and subsequent plasma electrolytic polishing is shown. Morphology and surface roughness, structure and microhardness of the modified layer were studied. The correla-tion of weight wear with hardness of diffusion layer at a low processing temperature and thick-ness of oxide layer is established – the largest decrease in weight wear occurs after nitrocarbu-rizing at 750 °C for 5 min (by 4.3 times). The possibility of an additional increase in wear re-sistance by subsequent polishing of the nitrocarburized CP-Ti surface at a voltage of 275–300 V for 3–5 min in chloride and fluoride electrolytes and 5–10 min in a sulfate electrolyte was re-vealed. Under these conditions, the hardened layer is preserved when the porous outer oxide layer is removed. According to the microtopology of the friction tracks, the wear mechanism is estimated as fatigue in dry friction and plastic contact.

The article focuses on the galvanic replacement synthesis of Ti-Ni and Zr-Ni metal systems with the "core-shell" structure which are potential precursors for intermetallics. The authors defined the effective synthesis parameters and the formation features of polymetallic systems character-ized by granulometric, phase and elemental composition. The X-ray fluorescence and X-ray phase analysis methods showed that the deposition of nickel on dispersed titanium and zirconium leads to the production of test samples with phase composition representing a mechanical mixture of Ni and Ti, Ni and Zr. The method of X-ray fluorescence analysis showed that the presence of hy-drofluoric acid with a 0.5-1.5 M concentration results in the formation of fixed quantitative ratios of elements in the precipitate, which allows the quantitative composition of dispersed systems "titanium - nickel", "zirconium - nickel" to be regulated within a relatively wide range. Scanning electron microscopy proved that all synthesized systems are characterized by a highly porous structure that follows the titanium and zirconium particle surface contour and the presence of spherical nanoscale subunits on the formed particle surface.

Keywords: friction stir processing; additive manufacturing; wire; titanium alloy; material transfer; microstructure; microhardness

Abstract The processing of anatase ores by sulfuric acid digestion is well known for its low titanium dissolution yields, which makes the process economically and technically unfeasible. Generally, to enhance the dissolution of titanium from anatase, thermal processes along with acid and/or alkaline leaching are necessary. Few existing works report yields of direct digestion of anatase with sulfuric acid <48%. This study investigated the sulfuric digestion of anatase and yields around 80% were obtained at relatively mild conditions such as temperature at 220°C, sulfuric acid/concentrate ratio of 1:2 and 3 hours of reaction. A comprehensive characterization of anatase ore was also presented.

This article describes the synthesis of hydroxyapatite (HAp) flakes through a microwave-assisted hydrothermal method. These flakes are intended for use as substrates for depositing titanium dioxide (TiO2) films using chemical vapor deposition with metal–organic precursors (MOCVD). The results reveal the formation of crystalline hydroxyapatite characterized by a uniform mor-phology. Additionally, we demonstrated the successful deposition of TiO2 coatings on the hy-droxyapatite flakes, resulting in a distinctive faceted prism morphology. Our findings affirm the effective synthesis of the HAp/TiO2 composite material. To further explore the material’s practical applications, we recommend assessing the photocatalytic activity of these composite membranes in future research.

Nano-titanium has excellent corrosion resistance and can be widely used in the field of corrosion resistant coatings. This paper introduces nano-weight titanium modified phenolic resin coatings and their anti-corrosion properties to explore the principle of nano-titanium modification and the mechanism of anti-corrosion to further develop more advanced corrosion resistant coatings. The article uses scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and UV-Vis spectrophotometer to characterise the morphology and structure of the nano-titanium modified phenolic resin coatings and to determine the corrosion resistance properties of the modified phenolic resin coatings. The results show that the 4% nano-titanium modified phenolic resin coating, nano-titanium powder and phenolic resin will maximize the dispersion and combination, and the structure is good; nano-titanium grafted on phenolic resin, the successful preparation of nano-titanium modified phenolic resin; modified nano-titanium added to improve the coating's ability of UV absorption. The corrosion resistance of the coating is much better than that of the unmodified phenolic resin coating.

The creep response of commercially pure titanium was investigated in air at 550, 600 and 650°C, to assess the effect of oxidation on the mechanical response. Experiments demonstrated that exposure at high temperature produced a marked reduction of the minimum creep rate under a given applied stress. Microhardness measurements showed that a hardened zone forms in proximity of the surface, due to oxygen penetration into metal. A simplified composite-model was then used to describe the creep response. In this model, the sample consisted of two zones, the hard case, enriched in oxygen, and the soft pure-titanium core, both creeping with similar strain rates. Calculation led to an estimation of the dependence of the minimum creep rate on stress and temperature for the hard high-oxygen zone. The simplified composite-model here presented gave an excellent description of experimental creep data for pure titanium tested in air and also provided a reliable picture of the effect of oxidation on complex Ti-alloys.

Hard coatings like Titanium diboride (TiB2) on silicon substrates are used for interconnects. micro-electro-mechanical devices and metallurgical protective coatings were analyzed based on shallow depths of nanoindentation penetration which involves a change in the nature of the contact from Hertzian to Pyramidal both in loading as well as unloading modes. Features like ductile fracture, linear unloading, and the creation of electrical conduction paths were analyzed. These high-precision features are influenced by the thickness and crystalline nature of the films and are significant for device fabrication.

The production of anatase titanium dioxide particles plays a crucial role in the sulfate process used for manufacturing white pigment. A key factor in improving the quality of white pigments is enhancing the thermal mixing process within the precipitation tank. This improvement ensures the uniform dispersion of seed particles instead of their agglomeration, leading to the formation of particles with uniform sizes. The objective of this study was to enhance three-phase CFD simulations involving the mixing process of H₂SO₄ solution, steam as a gas phase, and solid seed particles. By analyzing the trajectories of the seed particles using CFD, the optimal injection position for the seed particles within the mixing process was determined. Subsequently, lab scale test and real field test were conducted based on the insights gained from the CFD simulations. The particle size distribution of two different types of seed inlets was analyzed and compared using Transmission Electron Microscopy (TEM). The findings of this study demonstrate that the developed multi-phase CFD simulation can be effectively utilized to enhance the precipitation process for the production of anatase titanium dioxide particles.

The effect of defects and microstructure on mechanical properties of Ti-6Al-4V welds produced by tungsten inert gas welding, plasma arc welding, electron beam welding and laser beam welding was studied in the present work. The mechanical properties of the different weld types have been evaluated with respect to micro hardness, yield strength, ultimate tensile strength, ductility and fatigue at room temperature and at elevated temperature. Metallographic investigation was carried out to characterize the microstructures of different weld types and fractographic investigation to relate the effect of defects on fatigue performance. Electron and laser beam welding produced welds with finer microstructure, higher tensile ductility and better fatigue performance than tungsten inert gas welding and plasma arc welding. Large pores and pores located close to the specimen surface were found to be most detrimental to fatigue life.

Titanium alloys are difficult to machine and have poor tribological properties. This paper investigates the lubricating performance of γ-Al2O3/ZnO hybrid nanofluids for Ti-6Al-4V. The pure and hybrid nanofluid are compared, and the effects of γ-Al2O3/ZnO ratios are studied. The results show that γ-Al2O3/ZnO hybrid nanofluids outperform pure nanofluid in terms of lower friction coefficients and better surface quality. Moreover, the hybrid nanofluid with a mass ratio of Al2O3 to ZnO of 2:1 demonstrates the best lubrication performance with a reduced friction coefficient of up to 22.1% compared to the base solution, resulting in improved surface quality. Al2O3 nanoparticles can adhere to the surface of ZnO nanoparticles and work as a coating, which further enhances the lubrication performance of the water-based nanofluid.

Effects of plastic deformation on the indentation feature of hot-rolled commercial pure titanium alloy were detected using microindentation. It was found that the most deformed sample experienced the largest indentation resistance and had the maximum dislocation density and the indentation size influenced the CP-Ti indentation feature. The Vicker hardness and energy dissipated demonstrated the significant influence of the dislocation motion and size effects on the indentation in the indentation deformation. The linear relation of the energy ratio which is related to the microstructures and the indentation depth ratio was obtained for hcp materials Titanium alloys.

Titanium alloys belong to the metal biomaterials that are one of the most widely used in medicine. In recent years, in order to reduce the use of vanadium, Ti6Al4V alloy is increasingly replaced by Ti6Al7Nb alloy. In addition, to ensure the best possible biocompatibility, its surface is subjected to appropriate modifications, for example, anodic oxidation. Despite the extensive use of anodic oxidation of titanium implants in orthopedics, there are few works focused on a detailed analysis of the chemical composition of the surface layers. In addition, the effect of treatments before anodic oxidation on the properties of the produced layer has not been analyzed. Thus, the purpose of this study was to analyze in detail the chemical composition of the passive layer of Ti6Al7Nb alloy obtained by anodic oxidation preceded by sandblasting. Moreover, the physicochemical properties of the analyzed surface affecting biocompatibility were determined. For this purpose, surface observation, wettability and roughness tests, microhardness tests, electrochemical tests and phase composition analysis were carried out. In addition, the preclinical suitability, of the surface modified in this way, was evaluated by cytotoxicity tests.

Biomaterials are the basis for the development of medicine because they allow safe contact with a living organism. The aim of this work was to produce innovative oxide layers with a porous microstructure on the surface of commercially pure titanium Grade 4 (CpTi G4), and to characterize their properties as drug carriers. Anodization of the CpTi G4 subjected to mechanical grinding and electrochemical polishing was carried out in a solution of 1M ethylene glycol with the addition of 40 g of ammonium fluoride at a voltage of 20 V for 2, 18, 24 and 48 hours at room temperature. It was found that the longer anodization time, the greater the number of pores formed on the CpTi G4 surface as revealed by FE-SEM method, and the greater the surface roughness determined in profilometric tests. As the anodizing time increases, the amount of the drug in the form of gentamicin sulfate incorporated into the resulting pores decreases. The most favorable drug release kinetics profile determined by UV-VIS absorption spectroscopy was found for the CpTi G4 anodized for 2 h making them the best choice when it comes to the drug carrier allowing full use of the therapeutic dose of the drug.

The goal of this research is to determine the optimal microwave-assisted sol-gel synthesis pa-rameters of TiO2 nanoparticles with the achievement of the crystalline TiO2 nanoparticles with the highest specific surface area and the lowest energy band gap. Titanium isopropoxide was used as a precursor to prepare the sol (colloidal solution) of TiO2, isopropanol as a solvent, acetylacetone for complexation, and nitric acid as a catalyst. Four samples of titanium dioxide were synthesized from the prepared colloidal solution in a microwave reactor at a temperature of 150 °C for 30 minutes and at a temperature of 200 °C for 10, 20, and 30 minutes. The phase composition of the prepared samples was determined by X-ray diffraction analysis (XRD) and Fourier-transform infrared spectroscopy (FTIR). Nitrogen adsorption/desorption isotherms were used to determine the spe-cific surface area and pore size distributions by Brunauer-Emmett-Teller (BET) method. The band gap energy values of the TiO2 samples were determined by diffuse reflectance spectroscopy (DRS). CrystallineTiO2 nanoparticles with the highest specific surface area and the lowest energy band gap were obtained for the TiO2 sample synthesized at 200 °C for 10 minutes.