Titanium Powder Research Articles

Continuous flow photocatalytic reactor for degradation of selected pollutants: modeling, kinetics, mineralization rate, and toxicity assessment

This study focused on developing and evaluating a continuous flow photoreactor with an immobilized photocatalyst. The titanium dioxide powder was deposited on glass beads and packed into sequentially connected columns surrounded by LED lamps. The volume of the reactor without beads is 2.4 L, and with beads, 0.8 L. The photocatalytic efficiency of the reactor was evaluated by observing the degradation of Plasmocorinth B pollutant and selected pharmaceuticals (ibuprofen, sulfamethoxazole and diclofenac) at different flow rates under illumination of varying number of lights in deionized water and ISO medium. CFD simulations were performed to analyze the velocity and radiation field. The relationship between mass transfer and reaction kinetics was quantitatively evaluated by calculating the Peclet number, Damköhler number, and mass transfer coefficients. Total organic carbon (TOC) was also measured in the resulting solutions to determine the rate of mineralization. The toxicity tests were performed by exposing the solutions to the planktonic crustacean Daphnia magna for 48 hours. The results showed that the number of lights directly and the flow rate inversely affected the degradation of the parent compound. At lower flow rates, total degradation of 87-97% of the contaminants was observed in one flow and halving the light intensity resulted in a 10-15% decrease in overall degradation. The toxicity tests showed that toxic transformation products were formed and were present until the complete degradation of the parent compound, after which they were also degraded. This study shows that the continuous flow photoreactor presents a potential solution for large-scale wastewater treatment.

Zinc phytate@chitosan bio-powder renders explosion suppression of titanium powder involved in industrial processes

Zinc phytate@chitosan bio-powder renders explosion suppression of titanium powder involved in industrial processes

Recovery of Barium, Nickel, and Titanium Powders from Waste MLCC

The development of the electronics industry has led to an increased demand for the manufacture of MLCC (Multilayer Ceramic Capacitors), which in turn is expected to result in a rise in MLCC waste. The MLCC contains various metals, notably barium, titanium, and nickel, whose disposal is anticipated to increase correspondingly. Recently, recycling technologies for electronic waste have garnered attention as they address waste management and raw material supply challenges. This paper investigates the recovery of barium, nickel, and titanium from the MLCC by a hydrometallurgical process. Using citric acid, which is an organic acid, the metal inside the MLCC was leached. Additionally, metal materials were recovered through precipitation and complexing processes. As a result, barium and titanium were recovered from the leachate of the waste MLCC, and 93% of the nickel-based powder was recovered. Furthermore, the optimal recovery process conditions for recycling these metal elements were investigated.

A Novel Approach to Produce Metal–Metal Composites by Leveraging Immiscibility: Laser Powder Bed Fusion of Nanosilver‐Dispersed Titanium

The antimicrobial properties of silver ions are well known and effectively utilized in various biomedical applications. The efficacy of silver‐containing materials, particularly in terms of antimicrobial activity, heavily relies on the oxidizing surface, favoring nanosized silver features. However, producing such structures is challenging due to the high probability of miscibility in the liquid phase. Developing Ti–Ag composite alloys using the laser powder bed fusion technique with supported titanium powders and silver nanoparticles (AgNPs) represents a novel research pursuit, with no prior investigations reported. Incorporating AgNPs into titanium forms nanoislands, directly enhancing the antimicrobial efficacy of biomedical components. In this study, it is aimed to explore the solubility limit of silver in titanium and the feasibility of achieving finely dispersed silver islands. Experimental findings reveal that incorporating AgNPs into Ti‐based alloys results in discrete silver islands (0.01–0.02 μm2) within the microstructure, governed by the solubility limit of silver in titanium. In this study, valuable insights into producing components with augmented biocompatibility and proven antibacterial properties against Staphylococci infections are offered. The successful development of Ti–Ag composite alloys, featuring finely dispersed silver islands, opens promising avenues for biomedical applications, enhancing their antibacterial characteristics and improving patient outcomes.

Influence of highly dispersed phase of titanium carbide on physical and mechanical properties of alloys AM4.5Kd and AK10M2N

Dispersion-strengthened composite materials belong to the group of promising structural materials characterized by a diverse combination of properties. The work presents examples of the creation and heat treatment of composite materials based on aluminum alloys, strengthened by a dispersed phase of titanium carbide, and characterized by high hardness, elastic modulus and good wettability by the melt. The most accessible, inexpensive and effective way to obtain them is self-propagating high-temperature synthesis (SHS).The work shows the possibility of obtaining new aluminum matrix composite materials based on industrial aluminum alloys AM4.5Kd and AK10M2N by reinforcing them with 10 wt.% highly dispersed titanium carbide or AM4.5Kd–5.95 vol.% TiC and AK10M2N–5.78 vol.% TiC. The reinforcing phase is formed in alloy melts using the technology of SHS from the initial elemental components—titanium powder and carbon black. Using the obtained samples, an assessment was made of the uniformity of the ceramic phase distribution over the volume of the matrix alloys, which amounted to 0.15 and 0.12 for the samples AM4.5Kd–10%TiC and AK10M2N–10%TiC, respectively, which constitutes a high degree of uniformity.An assessment was made of physical properties such as porosity, density, electrical conductivity, as well as the coefficient of thermal linear expansion. Analysis of the data allows us to say that the final composite materials AM4.5Kd–10%TiC and AK10M2N–10%TiC have a slightly higher density (↑~4%) than the matrix alloys, due to the presence of a ceramic phase, low porosity values (~1%), lower TCLE (↓~6%) than matrix alloys and low electrical conductivity (~25% IACS). This article also presents data on the values of the mechanical properties of composite materials AM4.5Kd–10%TiC and AK10M2N–10%TiC. It has been shown that reinforcement with a ceramic phase contributes to a significant increase in hardness by 15 and 42 HB, as well as higher values of the compressive yield strength by 31 and 17 MPa, respectively, while maintaining a high level of relative deformation. The results obtained allow us to conclude that the developed composite materials can be recommended for products used under conditions of elevated temperatures and significant wear.

Comparative analysis of technological properties and microstructure of titanium powders of different classes of alloys

The results of a study of the technological properties of titanium powders of pseudo-α and pseudo-β alloys are presented. A comparative analysis of the characteristics of powder materials obtained by centrifugal spraying has been carried out. The results of the granulometric composition of the powders were obtained, and the calculation of the spatial packing of particles was applied within the framework of the hard sphere model for various fractional compositions. To compare the microstructure and mechanical properties, test samples from pseudo-α and pseudo-β titanium alloys were obtained using the hot isostatic pressing method according to selected modes.

Investigation of the Effect of Milling Time on Elemental Powders of Oxi‐Reduction Nickel and Hydrogenation–Dehydrogenation Titanium

Mechanical alloying (MA) is widely applied in the synthesis of blended elemental or prealloyed powders. This work evaluates the effect of milling time on elemental nickel and titanium powders produced by oxi‐reduction and the hydrogenation–dehydrogenation process, respectively. The powders are characterized by scanning electron microscopy, X‐ray diffraction, particle size, powder yield, and differential scanning calorimetry. It is observed that increasing the milling time promotes the formation of a structure composed of thin lamellae of nickel and titanium, which results in the beneficial effect of lowering the temperature for the formation of the intermetallic of the Ni–Ti system and in the powder yield achieved. The reduction of milling time in the MA process of NiTi alloys enhances technological efficiency by decreasing their overall processing time.

Highly Efficient Titanium Powder Production via Electro-Reduction of TiO2 in Commercial CaCl2 Molten Salt: Mechanism and Optimization Investigation

Highly Efficient Titanium Powder Production via Electro-Reduction of TiO2 in Commercial CaCl2 Molten Salt: Mechanism and Optimization Investigation

Study on the deep deoxidation mechanism of titanium powder using Y/YOCl/YCl3 and Y/Y2O3 systems

Low-oxygen high-purity titanium (oxygen concentration ≤ 500 ppm) is a critical material for advanced semiconductor and biomedical applications. Current deoxidation methods limit oxygen concentration in titanium to approximately 1000–2000 ppm, failing to meet the demand for ultra-low oxygen levels in high-performance materials. This study investigated the preparation mechanism and conditions for low-oxygen high-purity titanium utilizing a molten salt thermochemical method, employing Y as the deoxidant with a theoretical deoxidation limit below 10 ppm. We experimentally explored the deoxidation mechanisms of titanium using Y/YOCl/YCl3 and Y/Y2O3 systems, successfully reducing the oxygen concentration in titanium to 200 ppm, and proving that the Y/YOCl/YCl3 system is more efficient than the Y/Y2O3 system. Additionally, the titanium samples were analyzed using SEM-EDS, XRD, XPS, and 3D surface profilometry before and after deoxidation. These analyses examined the impact of the deoxidation process using Y on the crystal structure, oxide film, and surface roughness of titanium specimens, which are useful for understanding the deoxidation mechanism. During the sintering process of titanium powder attached to Y, the deoxidation process will produce YOCl or Y2O3. The formation of these deoxidation products leads to local oxygen diffusion, and the crystals of YOCl or Y2O3 are gathered at grain boundaries, which will resolve during the subsequent acid etching process, thus reducing the oxidation concentration of the titanium. The above results provide further theoretical guidance and technical support for the production of ultra-high-purity titanium powder.

Morphology and elemental composition of titanium powders for additive machines obtained by electrospark dispersion of OT4 alloy metal waste in propyl alcohol

Morphology and elemental composition of titanium powders for additive machines obtained by electrospark dispersion of OT4 alloy metal waste in propyl alcohol

Enhancement of corrosion, biocompatibility and drug delivery properties of nitinol implants surface by Al-Zn-LDH nanohybrids

This study investigates the enhancement of drug delivery and corrosion resistance by incorporating dexamethasone sodium phosphate into aluminum-zinc layered double hydroxide (LDH) coated nickel-titanium alloys. The nickel-titanium samples were fabricated from titanium and nickel powders using spark plasma sintering (SPS) and cold press sintering (CPS), followed by electrophoretic deposition of LDH nanoparticles. This composite construction aims to utilize the biocompatibility and mechanical properties of nickel-titanium, combined with the controlled drug release and corrosion resistance properties of LDH coatings. Structural and microstructural characterizations were performed using X-ray diffraction and scanning electron microscopy. The results indicated that SPS samples exhibited superior microstructural homogeneity and corrosion resistance compared to CPS samples. Dexamethasone sodium phosphate was successfully intercalated into the LDH layers, as evidenced by an increase in layer spacing from 7.14 Å to 20.130 Å. The LDH-coated nickel-titanium with intercalated dexamethasone sodium phosphate demonstrated a 5 % lower drug release rate and significantly improved corrosion resistance compared to uncoated samples. Cell adhesion studies confirmed good biocompatibility between cells and the coated surface. This composite material shows promise for enhanced performance in biomedical applications, particularly in drug delivery and corrosion resistance.

Synthesis and Characterization of Ti-13Ta-6Sn Foams Produced Using Mechanical Alloying, the Space Holder Method and Plasma-Assisted Sintering

Highly porous titanium foams are great candidates for replacing bone structures with a low elastic modulus owing to their ability to avoid the stress shielding effect. However, the production of highly porous foams (>70 vol.%) with well-distributed, stable, and predictable porous architectures using powder compaction and space holders is challenging. In this study, pure titanium powder and mechanically alloyed Ti-13Ta-6Sn were mixed with 50, 70, and 80 vol.% KCl powders as a space holder, cold-compacted, and sintered in a plasma-assisted sintering reactor to produce highly porous foams. The space holder was completely removed using heat and plasma species collisions prior to sintering. A Ti-13Ta-6Sn alloy powder with α, β, and metastable FCC-γ phases was synthesized. The characteristics of the alloyed powder, mixing step, and the resulting sintered samples were compared to those of CP-Ti. After sintering, the alloy exhibited α and β phases and a reduced elastic modulus. Foams with an elastic modulus in the range of the cortical and trabecular bones were obtained. The results showed the effects of the space holder volume fractions on the volume fraction, size, distribution, interconnectivity, and shape of the pores. The Ti-13Ta-6Sn foams exhibited a uniform open-celled porous architecture, lower elastic modulus, higher yield strength, and higher passivation resistance than CP-Ti. Ti-13Ta-6Sn exhibited a nontoxic effect for the mouse fibroblast cell line.

Interaction of liquid titanium with zirconates and titanates of some alkaline earth metals

Abstract The article presents the results of a study of the interaction of titanium melt with of zirconates BaZrO3 and SrZrO3, as well as titanate SrTiO3 under vacuum conditions and in an inert atmosphere at normal pressure. An original titanium heating method was used during the experiments. It eliminated the melt circulation at the interface between the solid and liquid phases. The method was based on resistive electrical heating of a Grade 2 titanium alloy rod or strip pressed into BaZrO3, SrZrO3 and SrTiO3 powders. Studied the structure, elemental, and phase composition of the products formed during various (up to 300 s) contact of titanium melt with surface zirconates and titaniums. The phase composition was compared with the products obtained by heating compacts from a mixture of titanium powders with BaZrO3, SrZrO3 and SrTiO3 powders. It was shown based on the results obtained that titanium, upon contact with these ceramic materials dissolves zirconium and oxygen and reduces barium and strontium to a metallic state. Barium and strontium evaporated due to the high vapor pressure at the experimental temperature, and caused the melt to splash or form a vapor layer that reduced the interaction rate of the melt with the ceramic. When a titanium melt interacted with BaZrO3 and SrZrO3 intermediate phases were not formed in quantities sufficient for their identification. The Sr3Zr2O7 phase was formed in small quantities during heating a mixture of Ti+SrZrO3 powders. When a titanium melt interacted with SrTiO3, a layer of an intermediate phase was formed, similar in composition to TiO2. Equations for the chemical reaction of the interaction of titanium with the indicated zirconates and titanate were compiled based on the experimental data obtained. It has been shown that titanium melt weted the surface of BaZrO3, SrZrO3 powders well and poorly weted the surface of SrTiO3 powder.

Elimination of cracks in Al–Zn–Mg–Cu alloy by addition of TiO2 in selective laser melting

7050 aluminium alloy is widely used in aerospace industry due to its excellent mechanical properties. 7050 aluminium alloy belongs to Al–Zn–Mg–Cu alloy. Due to the formation of cracks in selective laser melting (SLM) forming of Al–Zn–Mg–Cu alloys, 7050 aluminium alloy is difficult to be applied to forming and manufacturing in this technological field. In order to solve this critical problem, in this paper, titanium dioxide (TiO2) powder was mixed with 7050 aluminium alloy using ball milling method to achieve the effect of eliminating cracks. The cracks in the specimens completely disappeared when the TiO2 additions were 1.5 wt% and 2 wt%. With the addition of TiO2, the grains gradually changed from coarse columnar crystals to fine equiaxed crystals. Combined with the temperature field simulation, the grain refinement and crack elimination mechanism of TiO2 in SLM forming were analysed. The grain refinement is attributed to the formation of Al3Ti. The crack elimination was attributed to the reduction of the intergranular solid-liquid channel length. The maximum values of tensile strength and elongation of 7050 aluminium alloy formed by SLM are achieved at 2 wt% of TiO2. The values are 389 MPa and 8.8 %. The better mechanical properties were attributed to the synergistic effect of crack elimination, Hall-Petch, and Orowan strengthening. This study provides experimental guidance for the preparation of crack-free 7050 aluminium alloy.

Study of the Sintering Process Behavior on Some Structural and Physical Properties of (Ni-47Ti-3Cu) Alloy Prepared by Powder Metallurgy

This research aims to prepare the alloy (Ni-47Ti-3Cu) using powder metallurgy techniques and study the sintering behavior of this alloy at different temperatures. Powders of nickel, titanium, and copper, were mixed to ensure homogeneity, then compacted under a pressure of (5ton) for (2 min) to obtain cohesive samples. The sintering process was carried out at temperatures of (1050, 950, 850, 750, 650) °C for 1 hour. The structural properties were studied using X-ray diffraction (XRD), and the physical properties (apparent density, bulk density, porosity, and water absorption) were examined using Archimedes' principle-based tests. The XRD results indicated the emergence of a new phase with a different crystalline structure from the elements used in the preparation of the models, identified as (TiCuNi2) with a rhombohedral crystal system, while the constituent elements of the alloy exhibited face-centered cubic (F.C.C) structures for nickel and copper and a hexagonal close-packed (H.C.P) structure for titanium. The physical examination results showed that both apparent and bulk densities increased with increasing sintering temperature, while porosity and water absorption decreased with increasing sintering temperature.

Bioactive surface modification of Ti–Nb alloy by alkaline treatment in potassium hydroxide solution

Abstract The aim of this work is to compare the responsive behaviour of titanium, niobium and titanium–niobium alloy during alkaline treatment in forming alkaline titanate layer and their resultant bioactive properties. Titanium and niobium powder mixture with composition in the beta region was pressed at 550 MPa and sintered at 1,200 °C for 2 h. The alloy was soaked in potassium hydroxide aqueous solution at 60 °C for 24 h with different concentrations of 0.5 M and 5 M. The effect of post sintering-heat treatment was investigated by annealing the treated alloy at 600 °C for 2 h. X-ray diffraction analysis and Fourier transform infrared spectroscopy analysis were used to evaluate the chemical composition and the functional group of material on the treated alloy surface respectively. Immersion in Hanks solution for 1 day resulted in traces of calcium and phosphate on alloy surfaces treated in different concentrations of alkali as well as post-heat treatment. The cell viability evaluation using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay on the new beta-Ti alloy with potassium-based titanate layer demonstrated potassium hydroxide treatment with a 5 M concentration after post-heat treatment significantly improved cell proliferation, which is a prerequisite for bone mineral apatite deposition.

Possibility of using industrial by-product combinations to remediate cadmium and arsenic contaminated soil

It is inevitable to produce by-products in industrial and mining production, and how to deal with these by-products has become a major environmental issue. Meanwhile, many studies have shown that applying soil amendments is a feasible measure for effectively controlling soil pollution. Finding low-cost and efficient soil passivators is an effective way to safely utilize polluted soil. This article provides a method of “treating contamination with waste”. Through spinach pot experiments, different proportions and doses of granite powder (A, quarry waste), market purchased conditioner (B), “granite powder+iron sulfate mineral (titanium powder industrial waste)” (C), and “granite powder+iron sulfate mineral+market purchased conditioner” (CB) were used to treat soil co-contaminated with cadmium (Cd) and arsenic (As). The results indicate that amendments affect the available Cd and As in soil by changing soil pH and cation exchange capacity. The amendment of A, B, C, and CB all has remarkable reduction rates of soil available Cd at 65.48 %, 57.02 %, 61.37 %, and 43.15 %, respectively, compared to the control. Both A and B increase the available As content in the soil and the As content in spinach. However, both C and CB reduced the available As content in the soil by 60.32 % and 12.48 %. CB treatment could simultaneously reduce the accumulation of Cd and As in spinach, increase chlorophyll content, and promote spinach growth. It was worth noting that the 3 % CB treatment has the best effect, with Cd and As content in spinach stems and leaves decreasing by 51.13 % - 69.62 % and 35.46 % - 59.53 %, respectively, and the repair cost being as low as 76.5 $ ton−1. Therefore, the combined application of granite powder, market purchased conditioner, and iron sulfate minerals for the remediation of Cd and As co-polluted soil was a cost-effective and environmentally friendly technology. However, applying these soil composite amendments also requires attention to adjusting with the soil type and with pollution type, which we are currently studying.

Effects of doping of Sm, Y, Ce and La on crystal structure, phase and photocatalytic performance of TiO2 powders prepared by sol-gel method

In the present work, pure and 1 mol% samarium (Sm), yttrium(Y), lanthanum (La), cerium (Ce)-doped titanium dioxide (TiO2) powders were prepared by sol-gel method. Taking Methylene blue (MB) dye as degradation targets the photodegradation performance of the photocatalysts was studied. XRD spectra confirmed that the doping of rare earth elements (RE) could inhibit the transformation of TiO2 from anatase to rutile crystal at high temperature of 800 °C. XPS analyzed the chemical state of the elements in the powder. Characterization such as SEM and TEM found that the doping of the RE elements made the severely agglomerated particles become dispersed and refined, increased the specific surface area, and reduced the optical bandgap. Simulated visible light degradation results of MB showed that the degradation efficiency was significantly improved by doping of the RE elements, and the best efficiency is 88 % for Sm-doped TiO2 powder samples.

Investigation into the Fuel Characteristics of Biodiesel Synthesized through the Transesterification of Palm Oil Using a TiO2/CH3ONa Nanocatalyst

Biodiesel is a renewable and sustainable alternative fuel to petrol-derived diesel. Decreasing the operating costs by improving the catalyst’s characteristics is an effective way to increase the competitiveness of biodiesel in the fuel market. An aqueous solution of sodium methoxide (CH3ONa), which is a traditional alkaline catalyst, was immersed in nanometer-sized particles of titanium dioxide (TiO2) powder to prepare the strong alkaline catalyst TiO2/CH3ONa. The immersion method was used to enhance the transesterification reaction. The mixture of TiO2 and CH3ONa was calcined in a high-temperature furnace in a range between 150 and 450 °C continuously for 4 h. The heterogeneous alkaline catalyst TiO2/CH3ONa was then used to catalyze the strong alkaline transesterification reaction of palm oil with methanol. The highest content of fatty acid methyl esters (FAMEs), which amounted to 95.9%, was produced when the molar ratio of methanol to palm oil was equal to 6, and 3 wt.% TiO2/CH3ONa was used, based on the weight of the palm oil. The FAMEs produced from the above conditions were also found to have the lowest kinematic viscosity of 4.17 mm2/s, an acid value of 0.32 mg KOH/g oil, and a water content of 0.031 wt.%, as well as the highest heating value of 40.02 MJ/kg and cetane index of 50.05. The lower catalyst amount of 1 wt.%, in contrast, resulted in the lowest cetane index of 49.31. The highest distillation temperature of 355 °C was found when 3 wt.% of the catalyst was added to the reactant mixture with a methanol/palm oil molar ratio of 6. The prepared catalyst is considered effective for improving the fuel characteristics of biodiesel.

Interfacial characteristics and thermal stability of polymer-derived SiCf/Ti composite fabricated by powder hot isostatic pressing

The novel SiCf/Ti composite is prepared by hot isostatic pressing (HIP) with polymer-derived (PD) SiC fiber and powder titanium alloy as raw materials in this work. The interfacial characteristics and thermal stability of the PD SiCf/Ti composite have been systematically investigated. The interfacial properties of the PD SiCf/Ti composites are quantified to discuss the interfacial reaction mechanisms and kinetics. The results show that with the proposed HIP process, the powder matrix can be near-fully dense, and the matrix and SiC fiber are well bonded with a uniform interfacial layer. The major interfacial products are C-Ti compounds and Si-Ti compounds, which are formed by atomic diffusion reaction. During subsequent thermal exposure conditions, the interfacial layer growth is temperature-dependent and diffusion-controlled, following the parabolic relation and Arrhenius law. The frequency factor k0 is 102–103 times lower than that in the chemical vapor deposition (CVD) SiCf/Ti composites, showing better interfacial thermal stability. After thermal exposure, the element diffusion becomes significant, and the microhardness of the near-interface zone is noticeably greater than the matrix microhardness because of the atomic diffusion of C. The microhardness of both the matrix and near-interface zone reaches the highest value after 900 °C/9 h thermal exposure. It is concluded that the PD SiCf/Ti composites with good thermal stability can be successfully fabricated by powder HIP.