Titanium Composites Research Articles

Efficiency Estimation of Energy Introduction of a Ultrasound Field Into the Zone of Drilling of Complex Packages From Composite Materials and Titanium

The possibility of improving the quality of holes in complex packages made of composite materials and titanium alloys in the drilling operation by using the energy of ultrasonic vibrations introduced into the treatment zone is considered. The construction of complex packages and the problems arising from their processing with an axial tool are described. The rational design of the experimental setup for testing the technology of ultrasonic drilling of small-diameter holes was chosen. The unit is based on the KUKA KR 16 R2100 robotic complex. In addition to the industrial robot, it contains a spindle attached to the robot; Ultrasonic head, dynamometer and table, on which the package made of composite materials and titanium alloys is fixed. Ultrasonic oscillations with a frequency of 22 kHz can be transmitted, depending on the execution of the installation, either to the spindle or to the table with a complex package. The device allows carrying out experiments with the imposition of unmodulated, amplitude-modulated or frequency-modulated ultrasonic vibrations on the drill or on the object table with a package of composite materials.

Experimental installations for processing complex packages made of composite materials and titanium alloys and research of ultrasonic drilling processes

Experimental installations for processing complex packages made of composite materials and titanium alloys and research of ultrasonic drilling processes

Microstructure, microhardness, and wear performance of zirconia reinforced pure titanium composites prepared by selective laser melting

The study took selective laser melting (SLM) and strengthened pure titanium by adding zirconia particles in order to solve the low hardness, insufficient strength, and poor wear performance that pure titanium exhibits. The pure titanium’s properties were improved by the strengthening and toughening properties of zirconia. In this study, the zirconia reinforced pure titanium composites were successfully prepared by SLM, and the weight fraction of zirconia was 3%. The phase, the microstructure, the microhardness, and the wear performance of the SLM-processed samples were studied. The results showed that the zirconia reinforcement phase with the fine structure was evenly distributed in the pure titanium matrix. Due to the fine grain strengthening and dispersion strengthening of zirconia particles, the microhardness of the SLM-processed zirconia reinforced pure titanium composites was significantly improved. When the laser linear energy density was 333.33 Jm−1, the microhardness of the sample with zirconia added was 426.51 ± 15.20 HV, which was almost double the pure titanium sample. In addition, the addition of zirconia powder resulted in a significant improvement in the wear performance of the SLM-processed sample compared to pure titanium.

Superficial Characteristics of Titanium after Treatment of Chorreated Surface, Passive Acid, and Decontamination with Argon Plasma.

(1) Background. Titanium is characterized by its biocompatibility, resistance to maximum stress, and fatigue and non-toxicity. The composition, surface structure, and roughness of titanium have a key and direct influence on the osseointegration processes when it is used in the form of dental implants. The objective of the present study is to characterize, at chemical, superficial, and biological levels, the result of the application of the sandblasted with large-grit and acid-etched (SLA) treatment consisting of coarse-grained and double-passivated acid blasting with subsequent decontamination with argon plasma on the surface of titanium implants type IV. (2) Methods. Four Oxtein® dental implants (Zaragoza, Spain) were investigated with the following coding: Code L63713T (titanium grade IV, 3.75 mm in diameter, and 13 mm in length). The surface of the implants was SLA type obtained from coarse-grained, double passivated acid, and decontaminated with argon plasma. The samples were in their sealed packages and were opened in our laboratory. The X-ray photoelectron spectroscopy (XPS) technique was used to characterize the chemical composition of the surface, and the scanning electronic microscope (SEM) technique was used to perform topographic surface evaluation. Cell cultures were also performed on both surfaces. (3) Results. The superficial chemical analysis of the studied samples presented the following components, approximately, expressed in atomic percentage: O: 39%; Ti: 18%; C: 39%; N: 2%; and Si: 1%. In the same way, the topographic analysis values were obtained in the evaluated roughness parameters: Ra: 1.5 μm ± 0.02%; Rq: 1.31 μm ± 0.33; Rz: 8.98 μm ± 0.73; Rp: 5.12 μm ± 0.48; Rv: 3.76 μm ± 0.51; and Rc: 4.92 μm ± 0.24. At a biological level, the expression of osteocalcin was higher (p < 0.05) on the micro-rough surface compared to that machined at 48 and 96 h of culture. (4) Conclusions. The data obtained in our study indicate that the total carbon content, the relative concentration of titanium, and the roughness of the treatment performed on the implants are in agreement with those found in the literature. Further, the roughness of the treatment performed on the implants throws a spongy, three-dimensional surface suitable for bone growth on it. The biological results found are compatible with the clinical use of the surface tested.

Preparation of Visible Light Responsive Photocatalyst from Titanium Dioxide Nanotubes Modified with Antimony Trisulfide

Titanium dioxide (TiO2) nanotubes with a highly ordered structure were grown by a self-organized anodization process. The photodeposition process was used to improve the visible light response of titanium dioxide (TiO2) nanotubes. The irradiation was carried out with 500 W halogen lamp for 1, 5, 15, 30 and 60 min in the mixed ethanol solution of antimony trisulfide (Sb2S3). The obtained samples were annealed at 250 °C for 30 min. The morphology of the fabricated sample was characterized by a field emission scanning electron microscope (FE-SEM). The phase of samples was determined by X- ray diffractometer (XRD). The weight percentages of a component in the sample were measured by X-ray fluorescence spectrometry (XRF). UV-Vis diffuse reflectance spectra (DRS) of the samples were recorded. All titanium dioxide (TiO2) nanotube samples prepared by anodization process were anatase phase. All composite titanium dioxide (TiO2) nanotube /Sb2S3samples were a crystalline phase. The percentage of Sb and S increase with increasing of photodeposition’s time. The increasing photodeposition of antimony trisulfide (Sb2S3) on titanium (TiO2) nanotubes from 1 to 60 min lead to increasing of photoabsorption property of the material in the visible region.

Development of photocrosslinked salecan composite hydrogel embedding titanium carbide nanoparticles as cell scaffold

Salecan is a water-soluble extracellular β‑glucan and appropriate for preparing hydrogels applicable in biomedical field. Herein, an innovative photocrosslinked composite hydrogel composed of salecan/poly(hydroxypropyl methacrylate (PHPMA) network and titanium carbide (TiC) nanoparticles was successfully prepared. XRD patterns clearly showed the crystal planes of Ti. More importantly, the introduction of TiC nanoparticles into the hydrogel network provided structural reinforcement, and thereby synergistically enhanced the mechanical strength and thermal stability of the hydrogels. The change of salecan content markedly affected the swelling behavior and morphology of the composite hydrogels. Cytotoxicity results revealed that the composite hydrogels were non-toxic to L929 and 3T3L1 cells. Cell proliferation and Live/Dead assay further demonstrated excellent cytocompatibility of the cells within the composite hydrogels, which highlights the value of this system for potential application as soft tissue engineering scaffold.

Microstructural evolution and mechanical properties of in-situ as-cast beta titanium matrix composites

The aim of this research is to investigate the effects of B4C additions on microstructure refinement and mechanical properties, due to in-situ formation of TiB and TiC in a matrix of beta titanium by casting process. Researches have been done on the individual effects of TiC and TiB compounds in titanium composites, however, their hybrid effect has been scarcely explored in beta titanium alloys. The effects on lattice parameter were investigated by Rietveld refinement and EDS analysis. The beta lattice parameters increased due reaction between Ti and B4C. DTA analysis revealed the sequence of phase formation on heating and cooling around the melting point, being confirmed by investigation of orientation relationship between phases by EBSD and pole figure analysis. Orientation relationships are {312}TiB//{112}β, {112}TiC//{112}β for the smallest addition of B4C, {113}TiC//{112}β for the remaining composites, and {010}TiB//{011}TiC between the particles. Grain size reduced by half with 0.5% addition of B4C, while 3% addition made grains 25 times smaller than the alloy. Young's modulus and hardness increased with the addition of boron carbide. An analysis of the hardness of the materials was carried out from a nano to a macro scale. The as-cast composite materials have a refined structure with improved mechanical properties in comparison to the commercial alloy.

Dispersion of TiO2 Nanotubes in a Chitosan Matrix

ABSTRACTThis work presents the synthesis and characterization of TiO2 nanotubes (NTT) with chitosan (CS). In a first stage, electrochemical anodization of titanium foils was used to generate NTT in a membrane-type arrangement. From these experiments, suitable experimental conditions were selected. In a second stage, the synthesized NTT were detached from the titanium foils by sonication. In the third stage, the detached NTT were dispersed in an acid solution containing CS in various concentrations. Finally, the nanotubes-chitosan (NTT/CS) samples were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared Spectrometry (FTIR). Our results showed that the NTT presented very regular tube morphology with -OH and Ti-O- functional groups on the surface. The interaction of NTT and chitosan was enhanced by increasing the time of contact during the synthesis of the titanium composites.

Characterizations of Composite Titanium Nitride Coatings Deposited by Very Low-Pressure Plasma Spraying

In this study, composite titanium nitride coating deposition by reactive spraying was carried under a controlled low-pressure (150 pa) atmosphere with a F4-VB low-power plasma gun. Pure titanium powder is injected into the plasma, and a reactive gas (N2) is added on the substrate surface to generate nitriding reactions. The experiments were carried out at different radial distances of the plasma plume. Morphologies of the coating present quite dense binary structure deposited by molten, vapors particles. As measured by means of x-ray diffraction, the coatings composition is modified with an evolution of TiN0.3, Ti2N and TiN phase crystalline phases along radial distance of the plume. The nitride phases (Ti2N, TiN) contents of the coating show a linear relationship with the micro-hardness of the coating. Micro-hardness of VLPPS-processed composite titanium coatings reaches 1071HV0.03.

Thermodynamic analysis of oxygen refining during electron-beam additive manufacturing of pure titanium products

Chemical composition of pure titanium, particularly oxygen, severely affects mechanical properties of product. Oxygen refining during electron-beam additive manufacturing (EBAM) of pure titanium products was thermodynamically analyzed. The oxygen concentration of the titanium sample fabricated by EBAM was 0.172%, which was lower than that of the initial titanium powders (0.228%). This was mainly because the TiO2 native oxide layer formed on the initial powders reduced during EBAM, thereby decreasing the oxygen concentration. Analysis of temperature and oxygen partial pressure in the EBAM building chamber confirmed the occurrence of reduction and hence the oxygen refining effect.

Super hard carbon microtubes derived from natural cotton for development of high performance titanium composites

Super hard carbon microtubes derived from natural cotton are developed as a cost effective filler for composite applications. Two different carbon materials including synthesized carbon microtubes (CMT) and carbon nanotube (CNT) were used to produce titanium laminate composite via spark plasma sintering process. The sintering process was performed at 1200 °C for both Ti-CMT and Ti-CNT samples which led to the fully densified composites. The proposed mechanism confirmed by cross-sectional XRD investigation revealed formation of Titanium Carbide (TiC) between Ti layers as interfacial bonding phase. A significant improvement in bending strength (1273 ± 11 MPa) and hardness (537 ± 28 Vickers) of Ti-CMT composites was observed compared to titanium laminate and Ti-CNT composite. The results of current study demonstrate the considerable potential of inexpensive yet super hard carbon based material for various composite applications.

On the Interactions and Synergism between Phases of Carbon⁻Phosphorus⁻Titanium Composites Synthetized from Cellulose for the Removal of the Orange-G Dye.

Carbon–phosphorus–titanium composites (CPT) were synthesized by Ti-impregnation and carbonization of cellulose. Microcrystalline cellulose used as carbon precursor was initially dissolved by phosphoric acid (H3PO4) to favor the Ti-dispersion and the simultaneous functionalization of the cellulose chains with phosphorus-containing groups, namely phosphates and polyphosphates. These groups interacted with the Ti-precursor during impregnation and determined the interface transformations during carbonization as a function of the Ti-content and carbonization temperature. Amorphous composites with high surface area and mesoporosity were obtained at low Ti-content (Ti:cellulose ratio = 1) and carbonization temperature (500 °C), while in composites with Ti:cellulose ratio = 12 and 800 °C, Ti-particles reacted with the cellulose groups leading to different Ti-crystalline polyphosphates and a marked loss of the porosity. The efficiency of composites in the removal of the Orange G dye in solution by adsorption and photocatalysis was discussed based on their physicochemical properties. These materials were more active than the benchmark TiO2 material (Degussa P25), showing a clear synergism between phases.

Allergy to Surgical Implants.

Surgical implants are essential elements of repair procedures to correct worn out joints, damaged spinal components, heart and vascular disease, and chronic pain. However, many of the materials that provide stability, flexibility, and durability to the implants are also immunogenic. Fortunately, allergic responses to surgical implants are infrequent. When they do occur, however, the associated pain, swelling, inflammation, and decreased range of motion can significantly impair the implant function. Given the high numbers of joint replacements performed in the developed world, allergic reactions to orthopedic implants form the largest category of allergic responses. The most important allergens in this category include nickel, cobalt, chromium, and bone cement. These allergens are also the most important in reactions to spinal surgeries. Multiple cardiac and neurostimulatory devices are constructed of metals and adhesives that can be sensitizing in some individuals. Implantable pulse generators, important in cardiac pacemakers, gastric stimulators, and neurostimulators, may include components made of stainless steel, titanium alloy, platinum and iridium, epoxy resins, poly methyl methacrylates, and isocyanates, all of which are immunogenic in some patients. Cardiac stents and patches are often made of Nitinol, a composite of nickel and titanium. More surgical procedures are closed using skin glues, which are also capable of triggering a blistering contact dermatitis. Patch testing is the gold standard to determine sensitization, and this review provides a list of standard allergens to test for different implants. The patients most appropriate for testing include (1) pre-operative joint replacement patients with a prior history of skin reactions to metal jewelry, jean snaps, watch bands, metal glass frames, artificial nails, or skin glue; (2) post-operative joint replacement failure patients needing revision without an obvious cause such as infection or mechanical incompatibility; and (3) post-operative cardiac or neurological patients with localized rash, pain, swelling, or inflammation near or over the implant.

Influence of Fe3O4 Addition in TiO2 Catalyst on The Degradation Process of Methylene Blue

Synthesis of composite titanium dioxide with iron oxide magnetic material (Fe3O4/TiO2 composite) has been successfully carried out by precipitation method. Photocatalytic performance test of this composite Fe3O4/TiO2 was performed for degradation process of the methylene blue solution with the experiment parameters consist of the solution pH, lighting time, type of light, amount of catalyst, and the concentration of methylene blue. The experimental results showed that the Fe3O4 addition in TiO2 catalyst can simplify recovery process of the catalyst, and able to broaden the absorption area up to visible light, so that the degradation process can be carried out with UV and visible light. Degradation of methylene blue by Fe3O4/TiO2 composite in under sunlight more effectively compared UV light.

Enhanced (X-band) microwave shielding properties of pure magnesium by addition of diamagnetic titanium micro-particulates

Magnesium based micro-composites are known to have good mechanical integrity and are broadly investigated for different structural applications, however, their electromagnetic interference (EMI) protecting viability has rarely been studied. Thus, with an increasing interest in developing components made of magnesium alloys/composites for EMI SE (shielding effectiveness) applications, this study focusses on the electromagnetic shielding, electrical and magnetic properties of Mg/xTi (x = 5, 10, 15 wt %) micro-composites in correlation to the microstructure. The results indicated that there was grain refinement with progressive addition of Ti particulates in the Mg matrix. It was also found that the electrical conductivity of the composites decreased with increasing Ti amount. The magnetic characterisation performed on the samples verified that the composites are non-magnetic in nature. An interesting observation was made in this study pertaining to the SE values of the micro-composites. The SE values in the X-band microwave range (8.2–12.4 GHz) showed that with an increase in Ti wt%, the SE value remained equal among all the magnesium titanium composites, but improved in comparison to pure magnesium. This was attributed to decreased reflection (SER) (due to decrease in volume of Mg matrix with increase in amount of Ti reinforcements) and simultaneously increased absorption (SEA) (due to increase in amount of Ti which led to multiple internal reflection) coefficients of the shielding effectiveness.

Experimentally determined effects of olivine crystallization and melt titanium content on iron isotopic fractionation in planetary basalts

Olivine is the most abundant mantle mineral at depths relevant to oceanic crust production through melting. It is also a liquidus phase for a wide range of mafic and ultramafic magma compositions. We have experimentally investigated the effects of olivine crystallization and melt composition on the fractionation of Fe isotopes in igneous systems. To test whether there is a melt compositional control on Fe isotopic fractionation, we have conducted nuclear resonant inelastic X-ray scattering (NRIXS) measurements on a suite of synthetic glasses ranging from 0.4 to 16.3 wt.% TiO2. The resulting force constants are similar to those of the reduced (fO2 = IW) terrestrial basalt, andesite, and dacite glasses reported by Dauphas et al. (2014), indicating that there is no measurable effect of titanium composition on Fe isotopic fractionation in the investigated compositional range. We have also conducted olivine crystallization experiments and analyzed the Fe isotopic composition of the experimental olivines and glasses using solution MC-ICPMS. Olivine and glass separates from a given experimental charge have the same iron isotopic composition within error. This result is robust in both the high-Ti glass (Apollo 14 black) and low-Ti glass (Apollo 14 VLT) compositions, and at the two oxygen fugacities investigated (IW−1, IW+2). Additionally, we have determined that Fe loss in reducing one-atmosphere gas-mixing experiments occurs not only as loss to the Re wire container, but also as evaporative loss, and each mechanism of experimental Fe loss has an associated Fe isotopic fractionation.We apply our results to interpreting Fe isotopic variations in the lunar mare basalts and lunar dunite 72415-8. Our experimental results indicate that neither melt TiO2 composition nor equilibrium olivine crystallization can explain the observed difference in the iron isotopic composition of the lunar mare basalts. Additionally, equilibrium iron isotopic fractionation between olivine and melt cannot account for the “light” iron isotopic composition of lunar dunite 72415-8, unless the melt from which it is crystallizing was already enriched in light iron isotopes. Our results support models of diffusive fractionation to explain the light iron isotopic compositions measured in olivine from a variety of rock types and reduced (fO2 = IW−1 to IW+2) igneous environments (e.g., lunar dunite and basalts, terrestrial peridotites and basalts, martian shergottites).

Thermal Stability of the Structure and Phase Composition of Titanium Treated with Compression Plasma Flows

The results of studying the structure and phase composition of the surface layer of commercial pure VT1-0 titanium treated with compression plasma flows in nitrogen atmosphere and annealed in the temperature range of 400–900°C for 1 h are presented. Using the X-ray diffraction method, the α-Ti(O) solid solution is found to form in the titanium surface layer at 500°C, without pretreatment with plasma, and to transform into the titanium oxide TiO2 (rutile) phase at 600°C. Pretreatment of titanium with compression plasma flows promotes the formation of α-Ti(N) solid solution decreasing the rate of surface oxidation and increasing the initial temperature of rutile formation to 700°C, which indicates enhancement of the thermal stability of this structure.

Preparation and mechanical performance of graphene platelet reinforced titanium nanocomposites for high temperature applications

In this paper graphene platelet (GPL)-reinforced titanium (Ti) composites (GPL/Ti) were prepared using spark plasma sintering to evaluate a new type of structural material. The microstructure, mechanical properties and high temperature compressive properties of the GPL/Ti composites were studied. It was found that GPLs are well dispersed in the Ti matrix and the introduction of GPL results in the refinement of the Ti microstructure. Although x-ray diffraction results imply no traceable reaction products are produced in GPL/Ti composites, scanning electron and element analyses indicate titanium carbide particles are found along the interface between the GPL and Ti matrix. Compressive tests show that GPL/Ti composites exhibit higher yield strength and better compressive performance than the pure Ti samples. A maximum increase of approximately 43% and 37% in yield strength and compressive strength are achieved, respectively. Raman analysis suggests the reaction between GPLs and Ti results in the reduction in the number of the layers in graphene structure. The presented work suggests that GPL/Ti might be of great potential to be used as a structural material in various engineering fields.

Metal matrix to ceramic matrix transition via feedstock processing of SPS titanium composites alloyed with high silicone content

Titanium silicides are promising candidates for use as a reinforcement in advanced light-weight composites due to their excellent mechanical properties and oxidation resistance at high temperatures, sufficient wear resistance, and high chemical stability in various corrosion environments. Direct in-situ synthesis of such composites from titanium-silicon (Ti-Si) powder feedstock by spark plasma sintering (SPS) was used in this study with a particular attention on the effect of the powder processing parameters (blending, co-milling, milling + blending) on the microstructure formation and mechanical properties of the sintered composites. As opposed to the previous silicide-reinforced Ti studies, this was done for high silicone content (20 wt%). It was found that, despite the powders initial identical composition, the microstructure and phase content of the compacts varied significantly with the used powder fabrication route. Taking advantage of this, composites ranging from relatively soft metal-matrix (52 vol% metallic Ti; using non-milled Ti and coarse or fine-milled Si) to hard ceramic-matrix (11 vol% metallic Ti, using fine-dispersed joint-milled mixture of Ti and Si) were obtained. Due to in-situ formation of various TiSi2, TiSi, Ti5Si4 and Ti5Si3 silicide reinforcement phases contents with high hardness and stiffness, all the sintered composites showed superior hardness and wear resistance (an increase as much as 44×) in comparison to pure Ti. Importantly, hardness and elastic modulus of intermediate compounds TiSi2, TiSi, Ti5Si4 and Ti5Si3 were measured using instrumented indentation technique for the first time and are presented in the paper.

Carbon nanotube reinforced titanium composites: An experimental and molecular dynamics study

In this study, the mechanical properties of carbon nanotube reinforced titanium (CNT–Ti) composites have been predicted using molecular dynamics approach. An experimental study was also conducted in which spark plasma sintering was used for preparing the composites. The effect of variation in carbon nanotube volume fraction ( V f), temperature, and strain on the elastic moduli ( E11, E22, and E33) and the shear modulus ( G Reuss) of CNT–Ti composites was studied. The elastic and shear moduli were all found to increase significantly because of the increasing carbon nanotube V f. Even at temperatures approaching 1 K, the CNT–Ti composites show high values of elastic and shear moduli. The elastic moduli tend to attain a constant value at high levels of strain. The results obtained from experiments corroborated the molecular dynamics results.