Titanium Powder Research Articles

Somethings About Biological Prostheses

Finite element models of the female biofidel were developed using a specific combination of segmentation with computed tomography and solid modeling tools capable of representing bone physiology and structural behavior. This biofidel finite element (FEM) model is used to evaluate the change in the physiological distribution of stress in the femoral prosthesis and to evaluate the new design criteria for biopsy. Biomimetics, biomechanics, and tissue engineering are three multidisciplinary fields that have been considered in this research to achieve the goal of improving the reliability of prosthetic implants. The authors took these studies to gather the untapped potential of such advanced materials and design technologies by developing finite models of Biofidel elements capable of correctly mimicking the biomechanical behavior of the femur. The new remodeling of the tetrahedral elements was performed in 3Matic looking for the congruence of the node at the bone-implant interfaces, where the material was defined for the new configuration of the finite elements. The evaluation of the mechanical properties was made taking into account the mechanical characteristics of the cortical and trabecular bone. For biomechanical integration of the implant, a custom material with an improved combination of strength and rigidity that matches the bone should be used. This greater biomechanical compatibility will avoid weakening the implant and increase lifespan, avoiding additional surgery for revision and allowing good biological integration (bone growth). Innovative biomimetic materials for tissue engineering based on hydrophilic polymers were developed by our research group and presented attractive physical, biological, and mechanical properties for biomedical applications. For use with metal prostheses, the authors have developed a hybrid biocompatible material, extremely biocompatible, based on hydrophilic chemicals and hydroxy-ethyl-methacrylate type. The structural metal composition of the new prostheses will be made of titanium alloys using additive technology based on melting thin layers of titanium powder (about 50 microns) on each other until the desired component is obtained (sandwich method). Then, the biomaterial and osteoconductive nanostructured material developed in our previous studies can cover the titanium structural prosthetic skeleton. These hybrid biological prostheses, which are made using synthetic materials capable of inducing the growth of biological networks and structural steel scaffolding, may favor the emergence of new classes of orthopedic hybrids in the medical field. The new hybrid bio-prosthesis could drastically reduce protection against stress while providing an advantageous improvement in the life of the prosthesis compared to traditional solutions. Recovering optimal joint functionality will improve the patient's quality of life, which perceives a significant reduction in the risk of the new surgery. The requirement to predict potential structural changes that could be induced by improper use of biologically compatible prostheses in bone structure and morphology has forced our studies to evaluate fictitious models that could be considered for efficient bone distribution and orthotropic behavior.

Effect of Heat Losses on the Propagation of Cellular Waves in the Filtration Combustion of a Layer of Titanium Powder

Effect of Heat Losses on the Propagation of Cellular Waves in the Filtration Combustion of a Layer of Titanium Powder

A Study on Photocatalytic Efficiency of Hybrid Titanium Dioxide Nanowires/Reduced Graphene Oxide (TiO2NWs/RGO) for Degradation of Methyl Orange Dye

The major concern of this research is to improve photocatalytic efficiency by implementation of hybrid TiO2NWs/RGO for dye degradation. The TiO2NWs/RGO was prepared using fabrication method. Titanium (IV) oxide powder and graphite were used as precursors to synthesis of TiO2NWs and RGO, respectively. Physical and chemical properties of the photocatalyst was investigated by Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Adsorption-desorption nitrogen analysis and their photocatalytic efficiency was studied for methyl orange (MO) degradation. The hybrid almost achieved 100% of MO degradation within 210 minutes and shows the highest photocatalytic activity. Furthermore, It was fixed to the Langmuir–Hinshelwood model and the degradation of MO dye by each sample obeys first-order reaction kinetics that it shows a good performance of photodegradation rate of dyes by heterogenous catalyst. This is due the 1D/2D heterostructures of TiO2NWs/RGO hybrid that has a large surface area, unique optical properties, flexible structure and excellent mobility of charge carriers.

Materials based on the MAX phases of the Ti-Al-C system obtained under combustion and high-temperature shear deformation

Materials based on MAX phases with Ti2AlC and Ti3AlC2 stoichiometry have been obtained from initial titanium, aluminum, and carbon black powders under conditions combining combustion processes in the mode of self-propagating high-temperature synthesis and high-temperature shear deformation. It is shown that by controlling the green sample composition and synthesis conditions, it is possible to obtain a material with a given stoichiometry and with a controlled size of MAX phase lamellar grains, additionally hardened in situ by TiC and TiAl3. It has been established that the obtained materials have three main zones in cross section: (i) ceramic material consisting of MAX phases and hardening particles; (ii) transition region formed as a result of mutual diffusion of synthesis products and titanium; (iii) consolidated titanium. It has been established that the maximum microhardness (up to 800 HV) is achieved on the surface of the obtained materials, which decreases to 180 HV as it deepens towards titanium.

Preparation of bio-ceramic composite coatings on Ti6Al4V titanium alloy by gas-detonation spraying

The paper presents study of a new approach to manufacturing carrier implants with a combination of bioactivity, biocompatibility, and mechanical properties, composite powders of hydroxyapatite and titanium with a mass content of 50:50 % when sprayed by gas detonation spraying. Experimental studies of the surface morphology and cross-section microstructure, phase composition and mechanical properties of HATi composite coatings are obtained. The experimental results showed that the cross-section microstructures of HATi composite coatings are typical plate structures comprising curved strips formed by well-deformed and oxidized Ti plates and limited deformed HA plates. Composite coatings’ morphology and phase states were studied using scanning electron microscopy and X-ray diffractometry. It was found that the deprived coatings mainly consist of the phases HA, Ti and TiO. The elemental composition study results designated that the atomic ratio of calcium and phosphorus in the obtained coatings is Ca/P ~ 1.64, which is close to the value of the initial powder — Ca/P ~ 1.67. This indicates a limited change in the chemical composition during the coating formation.

Effect of magnesium in breaking the correlation between reaction speed and intensity in the fabrication of TiAl3 intermetallics

When TiAl3 intermetallics were fabricated by the reactive synthesis of titanium and aluminum powder, the correlation between the speed and intensity of the reaction was stable. The magnesium-addition method with the addition of trace magnesium broke this correlation for the first time. Magnesium controlled the reaction in three stages in different ways: the initial melting and reaction area, the dynamic equilibrium formed by the diffusion rate consistent with the liquidus, and the high flowability eutectic liquid phase. The diffusion state of magnesium in each stage and the eutectic liquid phase formed with aluminum were the critical factors.

Production of finely dispersed titanium powder by volumetric reduction of its ions with sodium dissolved in the BaCl2–CaCl2–NaCl melt

The research is intended to develop a technology for the production of finely dispersed (10 to 100 μm) powders of titanium and its alloys suitable for use in additive technologies after classification and spheroidization. A eutectic mixture was used as electrolyte, mole fractions: BaCl2 – 0.16, CaCl2 – 0.47, NaCl – 0.37, melting point of 452 °C. Electrolytes with a similar composition are used in industry for the electrolytic production of sodium with high current efficiency. No titanium salts were added to electrolyte. Sodium losses due to evaporation, corrosion, and ion recharge were replenished by a periodic increase in electrolysis current. A VT1-0 titanium plate was used as an anode. The walls of a steel crucible served as a cathode. Sodium was released on these walls and dissolved in electrolyte. Titanium ions were reduced in the bulk of electrolyte and in the anode layer. It is the first time that the results obtained were interpreted using the data on the electrode potentials of Ti3+/Ti, Ti2+/Ti, Ti3+/Ti2+ systems. It was shown that the concentration of slowly moving complex Ti3+ ions increases in the anode layer, and sodium dissolved in electrolyte reduces mainly Ti2+ ions in the electrolyte volume in the first 12 min of electrolysis. Starting from the 20th min, the concentration of Ti2+ ions in the anode layer begins to increase rapidly according to the reaction: 2Ti3+ + Ti = 3Ti2+ as titanium powder accumulates in the electrolyte volume. At the same time, the proportion of sodium consumed for the reduction of Ti3+ ions to Ti2+ decreases, which contributes to an increase in current efficiency and cathode potential stabilization for 30 minutes at –2.963 V. After the 50th min, the reactivity of the salt melt begins to decrease, the concentration of Ti3+ ions increases steadily until it levels off with the concentration of Ti2+ ions at the 85th min. This sharply increased the current consumption for ion recharge and made it necessary to stop electrolysis after switching on a current of 12 A for a short time (for 40 s). After 10 s, judging by the change in the cathode potential, sodium dissolved in electrolyte was almost completely consumed for titanium ion reduction. After 6 min, the potentials of electrodes returned to the initial anode potential value indicating that the system returned to its original state with the near-zero content of titanium salts and dissolved sodium. 95 % of powder was obtained in the electrolyte volume. Current efficiency was 84.0 % and turned out to be close to the value calculated from the average valence of titanium ions and the loss of anode weight (87.0 %). After ultrasonic dispersion, more than 80 % of powder was in the 10–100 μm range with a maximum at 36 μm. X-ray phase analysis showed that this is practically pure α-titanium (93.06 %) and oxygenated α-titanium (5.45 %). The originality of the research consists in the use of a volumetric, intensive, electrolytic method for producing finely dispersed titanium powders with no dissolved sodium and titanium chlorides in the initial and final electrolytes, in a stepwise increase in the current and potentiometric process control. The uniqueness of the research consists in the titanium powder obtained where the major part is in the melt volume in the form of intergrowths that are easily crushed by ultrasonic dispersion into individual crystals. Over 80 % of these crystals were in the range of 10–100 μm required for additive technologies with an average size of 36 μm.

Characterization of Porous Titanium-Hydroxyapatite Composite Biological Coating on Polyetheretherketone (PEEK) by Vacuum Plasma Spraying

Titanium powders and hydroxyapatite powders were used to fabricate the titanium and hydroxyapatite composite coating (Ti/Ti/HA) on the Polyetheretherketone (PEEK) by vacuum plasma spraying (VPS). The phase composition and morphology of the Ti/Ti/HA coating were analyzed by XRD, SEM, industrial CT, and three-dimensional contour profiler (DEKTAK XT). The results showed that the phase composition of the Ti/Ti/HA coating was dominated by the HA phase and a small amount of the Ti phase. The Ti/Ti/HA composite coating presented an obvious three-layer structure with different roughness and porosity. The bottom was Ti coating with a porosity less than 10%; the middle was porous Ti coating with a porosity of 35% ± 10%; the surface coating was HA coating with the crystallinity near 95%, a porosity of 32% ± 10%, a roughness Ra = 30 ± 10 μm. Moreover, the TG-DSC and ATR-FTIR results showed that VPS coating has no effect on thermochemical properties of PEEK material. The average bond strength of the composite coating was achieved 32 MPa.

Mechanical and Biocompatibility Properties of Sintered Titanium Powder for Mimetic 3D-Printed Bone Scaffolds.

A composite comprising Ti and NaCl powders was sintered similar to a three-dimensional (3D)-printed patient-customized artificial bone scaffold. Additionally, a proper microstructure of the mimetic scaffold and the optimum processing parameters for its development were analyzed. The mechanical properties of the metal-based porous-structured framework used as an artificial bone scaffold were an optimum replacement for the human bone. Thus, it was confirmed that patient-customized scaffolds could be manufactured via 3D printing. The 3D-printed mimetic specimens were fabricated by a powder-sintering method using Ti for the metal parts, NaCl as the pore former, and polylactic acid as the biodegradable binder. Scanning electron microscopy (SEM) images showed that pores were formed homogeneously, while X-ray computed tomography confirmed that open pores were generated. The porosity and pore size distribution were measured using a mercury porosimeter, while the flexural strength and flexural elastic modulus were calculated using the three-point bending test. Based on these measurements, a pore-former content of 15 vol % optimized the density and flexural strength to 2.52 g cm–2 and 283 MPa, respectively, similar to those of the actual iliac bone. According to the 3D-printing production method, a selective laser-sintering process was applied for the fabrication of the mimetic specimen, and it was determined that the microstructure and properties similar to those of previous metal specimens could be achieved in the as-prepared specimen. Additionally, a decellularized extracellular matrix (dECM) was used to coat the surfaces and interiors of the specimens for evaluating their biocompatibilities. SEM image analysis indicated that the adipose-derived stem cells grew evenly inside the pores of the coated specimens, as compared with the bulky Ti specimens without the dECM coating. The doubling time at 65% was measured at 72, 75, and 83 h for specimens with pore-former contents of 5, 10, and 15 vol %, respectively. The doubling time without the pore former was 116 h. As compared with the specimens without the pore former (73 h), 15% of the dECM-coated specimens showed a doubling time of 64%, measured at 47 h.

Structural Phase Transformations in Titanium Powders during Mechanosynthesis in Liquid Hydrocarbons

Structural Phase Transformations in Titanium Powders during Mechanosynthesis in Liquid Hydrocarbons

Influence of Titanium Powder on Detonation Characteristics and Thermal Stability of RDX‐Based Composite Explosive

AbstractTitanium, reserved abundantly in the earth, is a kind of metal with high energy density. In this study, RDX‐based titanium powder composite explosive is advocated by adding titanium powder into the RDX explosive as a dual additive. There are several stages in the energy release of composite explosives, and the initial chemical energy used for the detonation velocity tends to decline with the growth of the content of titanium powder. In the experiments, the maximum energy density Eρ of composite explosives is obtained with 20 % titanium powder through underwater explosion experiments, and it is increased by 15.33 % at 0.8 m and 19.31 % at 1.2 m compared with the RDX explosive, respectively, where more power would be obtained in limited space. At the same time, the thermodynamic parameters and kinetic parameters of TG‐DSC curves of composite explosives are studied, and it is determined that titanium powder is an insensitive agent to endow the composite explosives with good thermal stability. What's more, the results of this study may also support the mechanics of the safety performance of high energy explosives. Thus, titanium powder can be used as a potential energetic additive that plays a dual role in improving detonation characteristics and thermal stability of RDX‐based composite explosive.

Effect of Radiofrequency Plasma Spheroidization Treatment on the Laser Directed Energy Deposited Properties of Low-Cost Hydrogenated-Dehydrogenated Titanium Powder.

Titanium for additive manufacturing presents a challenge in the control of costs in the fabrication of products with expanding applications compared with cast titanium. In this study, hydrogenated–dehydrogenated (HDH) titanium powder with a low cost was employed to produce spherical Ti powder using the radiofrequency plasma (RF) technique. The spherical Ti powder was used as the raw material for laser directed energy deposition (LDED) to produce commercially pure titanium (CP-Ti). Microstructural analyses of the powder revealed that RF treatment, not only optimized the shape of the titanium powder, but also benefited in the removal of the residual hydride phase of the powder. Furthermore, the LDED-HDH-RF-produced samples showed an excellent combination of tensile strength and tensile ductility compared to the cast and the LDED-HDH-produced samples. Such an enhancement in the mechanical properties was attributed to the refinement of the α grain size and the dense microstructure. The present work provides an approach for LDED-produced CP-Ti to address the economic and mechanical properties of the materials, while also providing insights into the expanding application of HDH titanium powder.

Influence of ultrasonic vibrations on the properties of press-and-sintered titanium

In this study, longitudinal ultrasonic vibration was superimposed during the compaction of titanium powders. Then, specimens were vacuum sintered at 1273 K for 120 min. In order to investigate vibration influence on physical/mechanical properties, density, shrinkage, and compression strength of sintered samples were measured. The influence of powder size, compaction pressure, and aspect ratio also were studied on mentioned physical properties. Improvement of fine powder sintered samples density due to applied ultrasonic is greater than coarse powders, although their compacted density is lower than coarse powders samples. Dimensional stability (in the opposite of shrinkage) in coarse powder is greater than fine powders so that shrinkage in fine powders decreases up to 12%. Compression strength is improved due to the application of ultrasonic vibration up to 64%.

The Laser Alloying Process of Ductile Cast Iron Surface with Titanium Powder in Nitrogen Atmosphere

The article presents the results of the laser alloying process of a ductile cast iron EN-GJS 350-22 surface with titanium powder in nitrogen atmosphere. The aim of this research was to test the influence of nitrogen atmosphere on the structure and properties of the ductile cast iron surface layer produced by a laser alloying process with titanium. The laser alloying process was conducted using a Rofin Sinar DL020 2 kW high-power diode laser (HPDDL) with rectangular focus and uniform power density distribution in the focus axis. The tests of the produced surface layers included macrostructure and microstructure observations, X-ray diffraction (XRD) analysis, energy-dispersive spectroscopy (EDS) on scanning electron microscope (SEM) and transmission electron microscope (TEM), Vickers hardness and solid particle erosion according to ASTM G76-04 standard. As a result of the laser alloying process in nitrogen atmosphere with titanium powder, the in situ metal matrix composite structure reinforced by TiCN particles was formed. The laser alloying process of ductile cast iron caused the increased hardness and erosion resistance of the surface.

Evaluation of Mechanical Properties and Antibacterial Activity of Nano Titania-Enriched Alkasite Restorative Material: An In Vitro Study

Background: A biocompatible additive with the ability to establish antibacterial action for restorative materials without sacrificing their physical properties is always in demand. Nano titania (TiO2 nanoparticles) was shown to have antimicrobial action against a wide range of microorganisms. Alkasite is a modern esthetic restorative material that has outstanding properties; however, it is deficient in antibacterial activity. Objective: TiO2 nanoparticles (NPs) were included in alkasite, and both mechanical properties and antibacterial activity of the new formulations were assessed. Materials and Methods: Nano titania powder was coupled to alkasite powder in proportions of 3 and 5% (w/w). There were 105 specimens made in total. Evaluation parameters were compressive strength, surface microhardness, surface roughness, water sorption and solubility, and antibacterial activity. One and two-way ANOVA were used for the statistical analysis, followed by Tukey′s test (p<0.05). Results: Both ratios of nano titania, 3 and 5% (w/w), significantly increased compressive strength, antibacterial activity against different pathogens, and decreased water solubility of alkasite (p<0.05). Only 5% (w/w) nano titania-modified alkasite exhibited significant decrease in water sorption (p<0.05). Conversely, an insignificant increase in microhardness and surface roughness was observed with both ratios, 3 and 5% (w/w) of nano titania (p˃0.05). Conclusion: Nano titania seems to be a very promising complementary additive to the alkasite restorative material, capable of generating considerable antibacterial effectiveness while also enhancing certain mechanical properties.

Synthesis of a Composite Material via Combustion of Titanium and Boron Powders and a Mechanically Activated Aluminum + Nickel Mixture

Synthesis of a Composite Material via Combustion of Titanium and Boron Powders and a Mechanically Activated Aluminum + Nickel Mixture

Influence of powder properties and processing gas on the microstructural evolution of Armstrong CP-titanium and Ti6Al4V powders processed by cold spray

This paper studies the microstructural evolution of commercially pure titanium (CP-Ti) and Ti6Al4V powders manufactured by the Armstrong process deposited by cold spray with nitrogen and helium. The unique, coral-like morphology of the powders resulted in high density deposits sprayed with both nitrogen and helium carrier gasses. The plastic deformation of the CP-Ti and Ti6Al4V particles upon impact leads to refinement of the equiaxed grains present in the starting powder. CP-Ti deposits sprayed with nitrogen result in a grain size of 1 ± 0.6 μm while deposit processed with helium results in a grain size of 0.7 ± 0.2 μm with no clear difference between the grain size at particle interiors and at prior particles boundaries. The low levels of intragranular misorientation in the CP-Ti helium deposit indicated the presence of recrystallized grains. The higher grain refinement when using helium as carrier gas resulted in a weak basal plane (0001) fiber texture. Regions of ultrafine grains are also identified in the microstructure of Ti6Al4V analyzed by SEM. Microhardness values of the deposits made with these coral-like morphology powders were similar to CP-Ti and Ti6Al4V cold sprayed deposits produced with spherical powders. • The microstructure was refined in both the cold sprayed CP-Ti and Ti6Al4V deposits. • Recrystallized grains were identified in the cold sprayed CP-Ti deposit sprayed with helium gas. • EBSD of CP-Ti sprayed with helium gas revealed a weak texture in the basal <0001> direction. • The vanadium-rich regions presented in the Ti6Al4V powder are retained in the cold spray deposit.

Formation of the Ti2Alc Max-Phase in a Hydride Cycle From a Mixture of Titanium and Aluminum Carbohydride Powders

Formation of the Ti2Alc Max-Phase in a Hydride Cycle From a Mixture of Titanium and Aluminum Carbohydride Powders

Achieving high strength and toughness by engineering 3D artificial nacre-like structures inTi6Al4V-Ti metallic composite

Bio-inspired mimicking natural structures generally duplicate the three dimensional “hard brick-and-soft mortar” structure that may overcome the intrinsic brittleness of the brick, resulting in an improved mechanical performance. Here for the first time, we proposed an anti-bioinspired strategy of designing metallic composite with soft bricks (pure Ti) confined by hard mortars (Ti6Al4V alloy). The three-dimensional minority of hard mortar (with a volume fraction of ∼14%) is fabricated by using selective laser melting (SLM), while the bricks are introduced by filling the pure titanium powders followed by the hot isostatic pressing. The resulting nacre-like structured composite reveals a distinct periodic distribution of “soft-brick” and “hard-mortar” domains by a well-bonded interface with a well-bonded interface between them. This unique composite structure exhibits a combination of high strength and high fracture toughness that both exceed the respective value calculated using the rule of mixtures (ROM). Three dimensional heterogenous plastic deformations between the two domains induce the mechanical incompatibility, which has been confirmed by the presence of higher density of geometrically necessary dislocations (GNDs) in front of the interface. The large amount of GNDs was believed primarily responsible for the extraordinary strengthening and toughening beyond the ROM. This novel strategy of designing artificial three dimensional “soft brick-and-hard mortar” structure could be further applied to other metals and alloys, shedding lights on the development of innovative heterogeneous materials relevant to industry.

In Situ Ti6Al4V/TiB Composites Prepared by Hydrogen-Assisted Sintering of Blends Containing TiH2 and Ball-Milled Ti+TiB2 Powders.

In the present study, 98.6–99.5% dense in situ reinforced Ti6Al4V/TiB composites were manufactured with a newly developed approach based on hydrogen-assisted blended elemental powder metallurgy (BEPM). The approach includes the activation milling of titanium powder produced with hydrogenation-dehydrogenation (HDH-Ti powder) with finer TiB2 additives, following blending with TiH2 and master alloy (MA) powders, and final press-and-sinter operations. Scanning electron microscope (SEM) observations prove the formation of microstructures with improved density and homogeneous distribution of TiB reinforcements in a sintered Ti6Al4V matrix. Hardness and compressive tests validated the high mechanical characteristics of produced composites. The effect of preliminary milling time over 2–6 h and the ratio of hydrogenated and non-hydrogenated titanium powders used (TiH2 vs. HDH Ti) on microstructure and mechanical properties were studied to further optimize the processing parameters. Test results indicate the above approach can be regarded as a promising route for the cost-effective manufacturing of Ti6Al4V/TiB composite with reduced porosity, tailored microstructure uniformity, acceptable impurity level and, hence, mechanical characteristics sufficient for practice applications.