Ti Particle Size Research Articles

Quantity and Size of Titanium Particles Released from Different Mechanical Decontamination Procedures on Titanium Discs: An In Vitro Study.

Complications such as peri-implantitis could ultimately affect the survival of a dental implant. The prevention and treatment of peri-implant diseases require managing bacterial biofilm and controlling environmental risks, including the presence of pro-inflammatory titanium (Ti) particles in the peri-implant niche. Objectives included the evaluation of the size and quantity of Ti particles released from moderately roughened Ti surfaces during common mechanical surface decontamination methods. One hundred and forty moderately roughened Ti discs were divided into seven groups (n = 20 per group); six groups received mechanical decontamination procedures (ultrasonic scaling (US) with a metal tip and poly-ether-ketone (PEEK) under low and medium power settings, air-polishing with erythritol powder, and Ti brush), and the control group underwent air-water spray using a dental triplex. The rinsing solution was collected for Ti mass analysis using inductively coupled plasma mass spectrometry (ICPMS), as well as for Ti particle size and count analysis under scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). US metal tip instrumentation generated 34.00 ± 12.54 μg and 34.44 ± 6.08 μg of Ti under low and medium power settings, respectively. This amount of Ti generation was significantly higher than other instrumentation methods. The mean Ti particle size of the US groups ranged from 0.89 ± 0.27 μm to 1.25 ± 0.24 μm. No statistically significant difference was found in the particle size among US groups and Ti brush group (1.05 ± 0.11 μm), except for US with the PEEK tip, where a significantly smaller mean particle diameter was found at the low power setting (0.89 ± 0.27 μm). Mechanical instrumentation can produce Ti particulates and modify the implant surfaces. US using a metal tip generated the highest amount of Ti with smaller Ti size particles compared to all other commonly used mechanical surface instrumentations. The EDS analysis confirmed Ti in PEEK US tips. It can be suggested that deterioration from the PEEK US tip and Ti brush, as observed under SEM, is an additional source of Ti release during Ti surface decontamination.

Influence of Ti particle sizes on microstructure and mechanical behaviors of AZ91-Ti composites under different loading paths

Magnesium (Mg) matrix composites are recognized as the most promising light structural materials and have been extensively investigated, but they still suffer from a relatively low ductile nature which seriously affects their further development. Herein, the Mg–9Al–1Zn (AZ91) Mg matrix composites with different sizes of Ti particles reinforcement can be obtained via hot pressed sintering followed by hot extrusion. The microstructure demonstrated that the interfacial region is consisted of Mg17Al12 and Al-rich phase. Uniaxial tensile experiments revealed that the AZ91-Ti (particle size of 15 μm) composite achieves the optimal comprehensive mechanical properties, and the corresponding yield strength (YS), ultimate tensile strength (UTS), elongation (EL) of the composite can reach the high values of 210 MPa, 310 MPa, 15.5%, respectively. Moreover, with the decrease of Ti particle size, grain refinement and the strong interfacial bonding between Ti particles and Mg matrix render as-prepared the composites exhibited outstanding mechanical properties. Ti reinforcement particles of appropriate size can alleviate the plastic strain accumulation during the tensile and compressive cyclic loading, so that the excellent ductility of the composite is obtained. Constitutive relation of AZ91-Ti composites in this experiment can be derived from the nonlinear elastic relation. The simulated stress-strain curves of the composites reinforced by Ti particles with different sizes are consistent with the experiment.

Microstructural Analysis and Corrosion Behavior of a Titanium Cenosphere Composite Foam Fabricated by Powder Metallurgy Route

AbstractThis study examines the influence of cenosphere particle size and sintering parameters on the microstructure and electrochemical behavior of Ti‐cenosphere composite foam fabricated by powder metallurgy route. Cenosphere has been added as a space holder material to develop Ti composite foam because of its abundant availability and low cost. Ti (particle size between 250 μm and 350 μm) and cenosphere (with a varying particle size of <150 μm, 150 μm–200 μm and >200 μm) in the ratio of 75 : 25 (wt %) were compacted using 100 MPa of applied pressure and sintering temperatures of 1000 and 1200 °C with sintering time ranging from 2 to 6 h at a heating rate of 25 °C/min. A defect‐free microstructure with the uniform dispersion of cenosphere particles in the Ti matrix was observed with the cenosphere particles in the size range of 150–212 μm at a sintering temperature of 1000 °C for 4 h. The porosity content in the syntactic foam varied from 34 to 50 % and decreased with increasing sintering time and temperature. Based on a detailed study of corrosion behavior in Hank's solution, the composite foam with cenosphere particles in the size range of 150–212 μm and sintered at 1000 °C for 4 h showed the highest corrosion resistance.

Effect of Ti particles size on the microstructure and mechanical properties of TiP/VW94 composites

In the field of magnesium matrix composites (MMCs), it is vital to improve the strength of MMCs without sacrificing plasticity. In this work, TiP/VW94 composites with different Ti particle sizes were prepared by semi-solid stirring assisted ultrasonic vibration method and then subjected to homogenizing treatment. The microstructure results show that the Ti particles are conducive to forming the RE-rich phase. The Mn atoms diffused to the edge of Ti particles, and a submicron layer of MnTi formed at Mg/Ti interface. The atomic spacing misfit at the Mg/MnTi interface is 2.8%, indicating that a strong interfacial bonding was formed at the Mg/Ti interface. The tensile test results show that the strength and elongation all improved after adding Ti particles and improved first and then declined with the decrease of fine Ti particles and the increase of coarse Ti particles. The YS of D3 sample with 2.5% fine Ti particles and 1% coarse Ti particles increased by 12%, the UTS increased by 21%, and the elongation increased by 48% compared with the VW94 matrix alloy.

Combustion of 5Ti + 3Si Blends: Impact of Granule Diameter and Ti Particle Size

Combustion of 5Ti + 3Si Blends: Impact of Granule Diameter and Ti Particle Size

Combustion of Ti–C Powders and Granules: Impact of Carbon Allotropy and Ti Particle Size

Combustion of Ti–C Powders and Granules: Impact of Carbon Allotropy and Ti Particle Size

Study of the influence of titanium and niobium particle size on the Ti35Nb alloy production with controlled porosity

The present work is a continuation of the research carried out in a previous work, with the aim of improving the production of Ti35Nb alloy by reducing the particle size of Ti (from 50–149 Μm to < 53 Μm) and Nb (from 31–500 Μm to < 62 Μm) powders. Micro (MI) and Macroporous (MA) Ti35Nb alloy samples were processed by powder metallurgy. Ammonium bicarbonate (AB) was utilized as pore former additive for processing MA samples. The powders were mixed, uniaxially pressed and then sintered at 1300 ºC for 2 hours under argon atmosphere. The samples were characterized by SEM/EDS, XRD, profilometry, and Vickers hardness test. The porosity levels were determined by geometric method, Archimedes’ principle and quantitative metallographic analysis. The results showed that the processing parameters used in this work successfully produced porous Ti35Nb alloys with completely stabilized β-Ti phase, indicating an enhancement in the methodology when compared with those reported in previous work. Smaller particle sizes influenced positively on the chemical-physical properties of MI and MA samples, since they demonstrated an improvement in the their characteristics, such as: more homogeneous microstructure; better particle consolidation; homogeneous elemental distribution with no relevant chemical contamination; porosity values in accordance with literature; presence of low amounts of titanium oxides on the surfaces which can improve the biocompatibility features; suitable surface roughness parameters for bone implant applications and favouring adhesion of bioceramic coatings; more uniform microhardness values for both samples which make the material with a further predictable mechanical behavior.

Enhanced stability of Ti-containing silica catalysts for biodiesel epoxidation with hydrogen peroxide: Presence of strong metal–support interactions for alleviating permanent deactivation

The deactivation of titanium catalysts supported by well-ordered silica (SBA-15) and amorphous fumed silica synthesized by incipient wetness impregnation (IWI) and wet impregnation (WI) was comparatively investigated during epoxidation of methyl oleate with H2O2 at 50 °C. The formation of oxygen vacancies during epoxidation resulted in the loss of active species, leading to permanent catalyst deactivation. The WI-based catalysts exhibited superior stability to that of the IWI-based equivalents. Moreover, the use of SBA-15 as a support enabled higher stability than that of SiO2. The permanent deactivation rates for the 4Ti/SiO2-IWI, 4Ti/SBA-15-IWI, 4Ti/SiO2-WI, and 4Ti/SBA-15-WI catalysts were approximately 44.0%, 32.6%, 8.1%, and 0%, respectively. Various catalyst characterization data revealed that the configuration featuring stable surface Ti was present in the 4Ti/SBA-15-WI catalyst with strong metal–support interactions. This was attributed to the strong Ti4+ tetrahedral coordination achieved through Si–O–Ti bonds, the low degree of reducibility of the Ti catalyst, and the high dispersion and small particle size of Ti. Consequently, this modified surface can mitigate permanent catalyst deactivation caused by the surface oxygen vacancies.

Reaction Behavior of Porous TiAl3 Intermetallics Fabricated by Thermal Explosion with Different Particle Sizes.

Porous TiAl3 intermetallics were prepared by the thermal explosion (TE) and space holder method with different particle sizes of Ti and Al powders, and their reaction behaviors were investigated. The results showed that with the increase in the particle size of the Ti and Al powders, the interfacial contact between the particles decreased, resulting in low interfacial energy and reaction activity, making the process difficult to initiate. Meanwhile, the heat flow rose from 358.37 J/g to 730.17 J/g and 566.74 J/g due to the extension of the solid–liquid diffusion time. The TiAl3 structures obviously expanded, and the formation of connected pore channels promoted the porosity. Only when the Ti and Al particle sizes were both small did the solid–solid diffusion significantly appear. At the same time, the TE reaction weakened, so the product particles had no time to fully grow. This indicates that the particle size of the raw materials controlled the TE reaction process by changing the solid–liquid diffusion reaction time and the degree of solid-phase diffusion.

The effects of sintering temperature on mechanical and electrical properties of Al2O3/Ti composites

Al2O3-based composites containing 20 vol% Ti were fabricated at various sintering temperatures and the effects of Al2O3 grain size (RAl2O3) and Ti particle size (RTi) on mechanical and electrical properties were studied. Results indicated that toughening effects caused by Ti were enhanced with the growth of Ti particles while the large Al2O3 matrix grains showed a reverse effect on toughening. Composite containing adequate RAl2O3 and RTi (both below 2 μm) exhibited the highest flexural strength and fracture toughness when sintered at 1500 °C. For RAl2O3 below 2 μm, electrical resistivity dropped as RTi increased. But for RAl2O3 over 2 μm, electrical resistivity relied on the size of both matrix grains and metal particles. Percolation threshold volume of Ti varied with size ratio RAl2O3/RTi. It is speculated that when RAl2O3/RTi is close to 1, percolation threshold in Al2O3-Ti system might reach the lowest value. By controlling RAl2O3/RTi ∼ 1 and RAl2O3 < 2 μm, it is possible to fabricate conductive ceramic-metal composites with excellent mechanical properties containing metal phase with relatively low content. For the composites prepared from starting materials with various sizes, this study has important guiding significance.

3D ink-extrusion printing and sintering of Ti, Ti-TiB and Ti-TiC microlattices

Titanium metal matrix composite microlattices are fabricated using 3D ink extrusion printing and sintering. The inks consist of TiH2+TiB2 or TiH2+TiC powder blends to form (i) Ti-TiB composites by dehydrogenation and in situ reaction of Ti + TiB2 to form Ti + TiB and (ii) Ti-TiC composites, where TiC remains stable during the sintering process. Rapid densification of the printed powder blend is achieved during pressureless sintering in vacuum at 1200 °C between 1 and 4 h, due to the small Ti particle size available from dehydrogenation of micron-sized TiH2. Near-full density Ti-TiB and Ti-TiC is achieved within individual lattice struts, despite high TiB and TiC volume fractions up to 25 vol.%. The added TiB2 particles are fully dissolved and re-precipitated to TiB whiskers and whisker clusters in <0.5 h. The compressive properties of sintered cross-ply microlattices are measured for the three types of composites (Ti-TiB, Ti-TiC and Ti-TiC(W), with W originating from powder contamination) and pure Ti controls as a function of lattice orientation with respect to load. The compressive strength of the Ti-TiB/TiC composites increases from 55 to 1019 MPa as the designed lattice macroporosity is reduced from 71 to 24 %, and scales with the third power of relative density, indicating a high sensitivity of strength with relative density.

Morphology-Tuned TiO2 Photoelectrodes and Their Charge Transfer Behaviour: From 0- to 2-Dimensional Nanostructure

Anatase TiO2 photoelectrodes, consist of the different nanoparticle (sphere, sheet, rod) were synthesized using hydrothermal and spray coating method. The surface characterizations of TiO2 films were demonstrated by various analysis tool (TEM, XPS, XRD, DRS), and their photoelectrochemical activities were evaluated by controlling the film parameters (mass loading, surface area, thickness) under sulfite and sulfate solution. The particle size and oxidation state of Ti is nearly identical despite of shape difference; however, the band position estimation from the optical bandgap and valence band maximum (VBM) expects that TiO2 nanorod (TiO2 NR) leads to facilitate the separation of photogenerated electron-hole pair due to the lowest VBM position and narrow bandgap (Eg = 3.22 eV). TiO2 NR film exhibits superiority in the photocurrent generation, achieving ~4 mA cm-2 at 0.2 V vs. Ag/AgCl in all film parameter conditions. The IPCE of TiO2 NR achieved the highest values at 350 nm, and high APCE values indicate that restricted the charge recombination or charge carrier trapping on the surface. The fast charge transfer leads to the improvement of the photoelectrochemical performance of TiO2 NR film, which is demonstrated by Intensity-modulated photocurrent spectroscopy (IMPS) and charge injection efficiency. This study provides a significant insight between the morphology change and the charge transfer phenomena on the surface.

Effect of particle size and sintering time on the mechanical properties of porous Ti–6Al–4V implant

Titanium alloys have been extensively used in biomedical applications owing to its low density, excellent biocompatibility (i.e., biological and chemical inertness), and unique mechanical properties. However, there is a high disparity between Young's moduli of the implant and the natural bone. This disparity causes stress shielding in the body. This paper presents the effect of particle size and sintering time of Ti–6Al–4V powder used in the formation of a porous implant, sintered at 980 °C. Morphological characteristics of the sintered samples were obtained with a scanning electron microscope. The effect of surface hydrophilicity of the samples was elucidated via surface wettability testing using contact angle measurement with bio-fluid. Mechanical characterization was also evaluated with nanoindentation and a universal testing machine. The relation between Young’s modulus and sintering time was presented. It was observed that the wettability decreases with sintering time and the Ti alloy powder with particle size < 150 µm had the Young’s modulus that is closer to the modulus of the bone; the optimum sintering time was 5 h.

Pore structure of reactively synthesized nanolaminate Ti3SiC2 alloyed with Al

Ti3SiC2 has the unique properties integrating the advantages of metals and ceramics, and good open pore structure when alloyed with Al. In this work, porous Ti3SiC2 compounds with different Al/Si atom ratios were prepared through the reactive synthesis of elemental powders at 1300 °C. The results indicate that the phase compositions are determined by Al element mole number, and that the pore structure can be controlled through varying Ti particle size. The MAX phase transits from Ti3SiC2 with Al element mole number no more than 0.6 to Ti3AlC2 with Al element mole number in the range of 0.8–1.2. When Al element mole number is 0.6, the porous compound has a single MAX phase of Ti3SiC2 with uniform microporous structure and high bending strength. Porous Ti3SiC2 alloyed with 0.6Al has a slow linear increase rate of 0.0083%/μm in open porosity with increasing Ti particle size, and a strict linear relationship between the maximum aperture and Ti particle size with the increase rate of 0.0342 μm/μm. The pore structure formed by the phase transition mechanism for porous MAX phase has the smallest tortuosity factor compared with that formed by the clearance mechanism and the Kirkendall effect.

Synthesis and structural control of Fe-based porous layer on Fe substrate for joining with resin parts using combustion reaction

A porous Fe/TiB2 composite layer was synthesized on an Fe substrate by a powder metallurgy process using combustion reactions among Fe, Ti, and B to achieve Fe/resin joints through interpenetrating phase layers. The effects of Fe particle size and the blending ratio of the raw powder mixture on the porous structure, roughness of the top surface of the porous layer, and adhesiveness between the porous layer and Fe substrate were investigated. The peak temperature measured with a thermocouple increased with increasing Fe particle size and blending ratio of Ti and B. An increase in the peak temperature does not affect the porosity of the porous layer. Higher peak temperatures increase the pore size and change the pore morphology from open to semi-closed (although pores are not completely isolated). The change in pore morphology prevents the exposure of pores on the top surface of the porous layer, resulting in decreasing surface roughness. Moreover, an increase in the maximum temperature promotes bonding between the Fe substrate and porous layer. These results are discussed in view of the thermodynamic assessment using the calculated equilibrium phase diagram.

Microstructural and phase evolution of spark plasma sintering of graphitized Ti (C0.9N0.1) composites

Graphite addition on the particle grain sizes, multiple phases and the ultrafine Ti (C0.9, N0.1) composite produced by means of spark plasma sintering (SPS) was examined by means of X-ray diffractometer (XRD), and scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS). From the results analysed, the presence of graphite increased the porosity of sintered Ti (C0.9, N0.1) cermet and thereby crippled the sinterability of Ti (C0.9, N0.1). Significantly, graphite additions had an influence on particle size, morphology, microstructure and phases of ultrafine Ti (C0.9, N0.1) by inhibiting the dissolution of titanium carbonitride, outer rims phases and the inner rim formation, thereby causing grain growth reduction. Because of depressed dissolution and solution precipitate, graphite phase evolution in the composite has reduced. Furthermore, the presence of graphite improved the micro indentation hardness of Ti (C0.9, N0.1) composite and sintered relative density of the cermets.

Precipitation Behavior and Microstructural Evolution of Ferritic Ti–V–Mo Complex Microalloyed Steel

Precipitation behavior of (Ti, V, Mo)C and microstructural evolution of the ferritic Ti–V–Mo complex microalloyed steel were investigated through changing coiling temperature (CT). It is demonstrated that the strength of the Ti–V–Mo microalloyed steel can be ascribed to the combination of grain refinement hardening and precipitation hardening. The variation of hardness (from 318 to 415 HV, then to 327 HV) with CT (from 500 to 600–625 °C, then to 700 °C) was attributed to the changes of volume fraction and particle size of (Ti, V, Mo)C precipitates. The optimum CT was considered as 600–625 °C, at which the maximum hardness value (415 HV) can be obtained. It was found that the atomic ratios of Ti, V and Mo in (Ti, V, Mo)C carbides were changed as the CT increased. The precipitates with the size of < 10 nm were the V-rich particles at higher CT of 600 and 650 °C, while the Ti-rich particles were observed at lower CT of 500 and 550 °C. Theoretical calculations indicated that the maximum nucleation rate of (Ti, V, Mo)C in ferrite matrix occurred around 630 °C, which was consistent with the 625 °C obtained from experiment results.

Study on titanium-magnesium composites with bicontinuous structure fabricated by powder metallurgy and ultrasonic infiltration.

Titanium-magnesium (Ti-Mg) composites with bicontinuous structure have been successfully fabricated by powder metallurgy and ultrasonic infiltration for biomaterial potential. In the composites, Ti phase is distributed continuously by sintering necks, while Mg phase is also continuous, distributing at the interconnected pores surrounding the Ti phase. The results showed that the fabricated Ti-Mg composites exhibited low modulus and high strength, which are very suitable for load bearing biomedical materials. The composites with 100 µm and 230 µm particle sizes exhibited Young's modulus of 37.6 GPa and 23.4 GPa, 500.7 MPa and 340 MPa of compressive strength and 631.5 MPa and 375.2 MPa of bending strength, respectively. Moreover, both of the modulus and strength of the composites increase with decreasing of Ti particle sizes. In vitro study has been done for the preliminary evaluation of the Ti-Mg composites.

Fine Ti‐dispersed Al2O3 composites and their mechanical and electrical properties

AbstractAl2O3/Ti composites containing 0‐30 vol% dispersed fine Ti particles were fabricated using a hot‐press sintering method at 1500°C from mixtures of Al2O3 and TiH2 powders. During sintering, TiH2 decomposed to form metallic Ti. The effects of the Ti content on the mechanical and electrical properties of the composites were then investigated. No Ti‐Al intermetallic compounds were detected by X‐ray diffraction, and energy‐dispersive X‐ray spectroscopy indicated the presence of Al‐Ti‐O solid solution and Ti‐O phases. The composites showed enhanced densification; the measured densities were higher than the calculated theoretical values. Microstructural observation revealed homogeneously distributed fine Ti particles dispersed in the Al2O3 matrix. The Ti particle size ranged from submicrometer to a few micrometers depending on the Ti content. The fracture mode of the composites was primarily transgranular, in contrast to the intergranular fracture mode of monolithic Al2O3. Although the flexural strength was decreased with increase in Ti content, the composite containing 20 vol% Ti displayed the maximum fracture toughness of 4.3 MPa·cm1/2, which was 37% greater than that of monolithic Al2O3. The composites containing more than 15 vol% Ti exhibited drastic decreases in resistivity (~10−1 Ωcm), which were attributed to the formation of interconnected Ti networks at these Ti contents. The percolation threshold volume for electrical conduction in the present system was calculated to be 13.8 vol%. The results indicate that dispersing fine Ti particles into Al2O3 increased the fracture toughness and improved the conductivity of Al2O3.

Ti Reactive Sintering of Electrically Conductive Al2O3–TiN Composite: Influence of Ti Particle Size and Morphology on Electrical and Mechanical Properties

In the current study, Al2O3–TiN composites were successfully fabricated with various particle sizes (10, 20, 30, and 50 μm) and concentrations (5, 10, 15, and 20 vol %) via a novel ball milling + Ti reactive sintering process. By applying the reactive sintering, Ti powders will transform into TiN particles, which act as mechanical reinforcements and electrical conductors in the Al2O3 matrix. The ball milling process alters the Ti powder morphology from a low-aspect-ratio sphere into a high-aspect-ratio disc, which reduces the electrical percolation threshold value from 29% to 15% in the current setup. However, such a threshold value is insensitive to the particle size. Meanwhile, the Ti particle size has a significant influence on the material’s mechanical properties. A small particle size results in less porosity and hence higher flexural strength of the composite.