Mechanical Properties Of Titanium Research Articles

Effect of microalloying with rare-earth lanthanum on dynamic recrystallization behavior and mechanical properties of Ti sheets

This study examines the influence of microalloying with rare earth lanthanum (La) on the dynamic recrystallization behavior and mechanical properties of Titanium (Ti) sheets. A distinctive wedge-shaped specimen was employed for experimental efficiency, enabling continuous gradient strains to be applied to the Ti-La alloy during hot-rolling, facilitating the assessment of changing microstructural, textural, and hardness features as strain increased from low to high levels. The hot-rolled plates were performed using analytical methods such as optical microscopy (OM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and hardness testing. The results show that the hardening process can be divided into four stages under continuous gradient strain (0 ∼ 0.5, 0.5 ∼ 0.7, 0.7 ∼ 1.2 and 1.2 ∼ 1.6). During these stages, grain refinement and dislocation strengthening emerge as critical contributors to changes in hardness. Furthermore, it was determined that dynamic recrystallisation (DRX) of Ti-La alloys during hot rolling occurs at the fourth stage. Analysis of the orientation distribution function (ODF) reveals that the dominant textures during this process include {1̅21̅0}, {011̅0}, and {0001} textures. When compared with commercially pure titanium (CP-Ti), the Ti-La alloy shows significantly delayed DRX under identical conditions. The DRX grain growth appears suppressed, attributable to the presence of La-rich particles on the grain boundaries. Moreover, the texture associated with rolling deformation seems subdued, providing a desirable base for future cold rolling and heat treatment.

Heterogeneous precipitate microstructure design in β-Ti alloys by regulating the cooling rate

Cooling after solutionizing or aging plays a crucial role in heat treatment and can greatly influence the final precipitate microstructure and mechanical properties of titanium (Ti) alloys. In this study, we employ phase field simulations to strategically engineer heterogeneous precipitate microstructures in near β-Ti alloys by manipulating the cooling rate, which leads to different phase transition mechanisms. By varying the cooling rate within the temperature range of 900 ∘C to 500∘C, we identify four distinct microstructures: uniformly distributed fine congruent αc plates and fine α precipitates, heterogeneous and hierarchical α precipitates, and uniformly distributed coarse α precipitates. Further analysis reveals that these diverse precipitate microstructures originate from three distinct phase transition mechanisms, i.e., congruent transition, pseudospinodal decomposition, and classical nucleation and growth, each activated at different temperatures during continuous cooling. Utilizing the insights from the simulations, we successfully produce microstructures in Ti-5Al-5Mo-5V-3Cr-1Zr (Ti55531) with heterogeneous α precipitates by applying intermediate cooling rates (∼0.01∘C/s), which activate classical nucleation and growth as well as pseudospinodal decomposition. These samples exhibit exceptional comprehensive mechanical properties, including an ultimate strength of approximately 1260 MPa and a total elongation of around 14 %. This investigation provides valuable guidance for designing novel heterogeneous precipitate microstructures by simply controlling the cooling rate, leading to significant enhancements in the mechanical properties of β-Ti alloys.

Study of the Physical and Mechanical Properties of Titanium in Volume by the MEAM Method

Study of the Physical and Mechanical Properties of Titanium in Volume by the MEAM Method

Diffusion of hydrogen in the Volterra elastic fields around dislocations in α-Ti: Coupling DFT calculations and elasticity method

Hydrogen around dislocation has a great influence on the mechanical properties of Titanium (Ti) alloys. In this study, the diffusion of hydrogen around dislocations in α-Ti alloys is investigated by coupling density functional theory (DFT) calculations and the elasticity method. Initially, the attempt frequency and hopping activation energy of hydrogen atom in the α-Ti lattice are calculated using the DFT method under various simple strain fields, including volume strain, biaxial strain, and shear strains, within a strain range of −2%–2 %. It is observed that both volume strain and biaxial strain have the most pronounced effects on the hopping activation energy of hydrogen atom, while the attempt frequency remains relatively unaffected across different strain conditions. Subsequently, the hopping activation energy in the elastic strain field has been parameterized using an elasticity method based on elastic dipole and diaelastic polarizability. Using the elasticity method, an analysis is conducted on the effective activation energy of hydrogen atoms and their hopping tendencies in the Volterra elastic strain fields around the perfect edge and screw dislocations. The elastic strain field around screw dislocation enhances the diffusion of hydrogen atoms and simultaneously promotes their migration toward the dislocation core. In the vicinity of edge dislocation, the tensile elastic strain field enhances the diffusion of hydrogen atoms and facilitates their migration toward the dislocation core. Conversely, the compressive strain field retards the diffusion of hydrogen atoms and promotes their migration away from the dislocation core or towards regions with tensile strain.

Tribological characterization of TiVN trilayer coatings synthesized by sputtering for biomedical applications

The behavior of TiVN on the tribological and mechanical properties of titanium, as well as its biocompatibility for use as a biomaterial, is studied. The coatings are deposited using direct current magnetron sputtering on titanium substrates, with varying deposited power of titanium and vanadium on the surface layer. During the process of obtaining the TiVN coating, TiN and VN are deposited as interlayers to enhance the adhesion between the coatings and the substrates. The average thickness of the obtained coatings is 1.2 μm. The chemical characterization, nanohardness tests, and tribocorrosive behavior are evaluated using potentiodynamic polarization tests., A pin-on-disk wear test was used to study the tribocorrosion behavior of the coating systems and determine their synergistic behavior. The coupling with potentiodynamic polarization tests improved the corrosion resistance of the system from 2.76 μ to 1.86 μA. Notably, there was a significant enhancement in corrosion resistance, with average corrosion current values of 2.54 μA/cm2 and a coefficient of friction of 0.35. Additionally, hardness values of 15.6 GPa were observed, compared to 4.51 GPa for the substrate., As the working power for each element was increased. As well as exhibiting good behavior in the relationship between wear and corrosion for TiVN1 to TiVN4 coatings, there was an antagonistic-synergistic behavior observed for the TiVN5 to TiVN8 coatings. Additionally, the biocompatibility of the ternary systems was evaluated, and the samples incubated in the TiVN coatings showed good cell viability.

The effect of adding Sn on the mechanical properties and microstructure of the titanium

Ti-XSn (X = 0, 5, 10, 15) (wt. %) alloys were prepared by blending TiH2 and Sn powder compact extrusion. The effect of adding tin (Sn) on the microstructure and mechanical properties of titanium has been investigated by optical microscopy and tensile tests. The lamellar thickness (10 to 6.6 µm) of the Ti reduced after adding Sn and according to the Hall-Petch equation the yield strength (548.2 to 801.3 MPa) and microhardness (233.2 to 310 HV) of the Ti is increased with increasing the tin (Sn) content.

Structure and mobility of -type screw dislocation in presence of H in α-Ti from first-principles

Hydrogen has both negative and positive effects on the mechanical properties of titanium and titanium alloys. It has been reported that the plastic deformation of titanium is controlled by the <a>-type screw dislocation and the principal slip plane is the prismatic plane. Herein, we employ first-principles calculations to investigate the modification of the <a>-type screw dislocation core structures caused by addition of H and the interactions between them. It reveals that H is attracted to the pyramidal dislocation partial and tends to segregate to the dislocation region. Then, the slip paths of the <a> screw dislocations along different slip planes in the H inserted Ti system are studied. Furthermore, the mechanism on how H affects the strength and plasticity of Ti under different H concentrations through the change of dislocation mobility is discussed.

Mechanical changes of sandblasted Ti-6al-4v using 100 μm Al2O3 after dynamic pressure treatment: In vitro study

Background: Implant materials have been developed in such a way to fulfill various requirements of mechanical properties, one of the methods to change mechanical properties of implant is the sandblasting method. Purpose: This study aimed to determine the changes in mechanical properties of Titanium 6 Alloy 4 Vanadium (Ti-6Al-4V) sandblasted using 100μm Al2O3 after dynamic stress treatment. Method: 32 Ti-6Al-4V implant samples divided into two groups, 16 samples of treatment group (PI) and 16 samples of control group (PII). The PI group is Ti-6Al-4V sandblasted by Al2O3 100 and the PII group is Ti-6Al-4V machined surface. Both groups of samples were given dynamic treatment as much as 2 million times and then performed a compression test. Results: The results of data analysis showed PII&gt; PI and there was a significant difference (p&lt;0.05) between the PI and PII groups. Conclusion: In conclusion, there's difference in mechanical properties of sandblasted Ti-6Al-4V using 100μm Al2O3 after dynamic pressure treatment.

Characterization of microstructure and mechanical properties of titanium -based bioactive ceramics laser-deposited on titanium alloy

Titanium-Based Bioactive Ceramics (TBBC), obtained by laser deposition of Ti and hydroxyapatite (HAp) powders, are the preferred materials for the clinical application of mandibular implants which are beneficial for bone tissue regeneration. So far, the bonding strength of TBBC fabricated by traditional additive manufacturing techniques reported in literature is no more than 35 MPa. Therefore, the main problem that restricts the application of this material on the mandible is the low bonding strength with the matrix. Unfortunately, the effective method to improve the bonding strength of TBBC is rarely mentioned. Under this circumstance, TBBC fabricated on artificial mandible are prone to peeling off during the bite and chew. In order to improve the mechanical properties of materials without losing the biological activity, this paper firstly studied the interaction mechanism between laser beam and Ti-HAp mixed powders. Afterward, two major crack avoidance factors, dilution rate and overlap rate, were analyzed to determine the optimal laser deposition parameters for TBBC. Finally, the mechanical performances were comprehensively studied. Of course, the biological activity of the TBBC was also preliminarily evaluated in Simulated Body Fluid (SBF). The results show that the fabricated TBBC have a bonding strength of 177.3–338.6 MPa, at least 5 times higher than the traditional process of 35 MPa. Furthermore, the increase of the maximum mass ratio of HAp powders to 15% will generate the bio-phase of Ca3(PO4)2, which provides a better Ca/P environment with PO43− needed for bone tissue regeneration.

A state-of-the-art review of the fabrication and characteristics of titanium and its alloys for biomedical applications.

Commercially pure titanium and titanium alloys have been among the most commonly used materials for biomedical applications since the 1950s. Due to the excellent mechanical tribological properties, corrosion resistance, biocompatibility, and antibacterial properties of titanium, it is getting much attention as a biomaterial for implants. Furthermore, titanium promotes osseointegration without any additional adhesives by physically bonding with the living bone at the implant site. These properties are crucial for producing high-strength metallic alloys for biomedical applications. Titanium alloys are manufactured into the three types of α, β, and α + β. The scientific and clinical understanding of titanium and its potential applications, especially in the biomedical field, are still in the early stages. This review aims to establish a credible platform for the current and future roles of titanium in biomedicine. We first explore the developmental history of titanium. Then, we review the recent advancement of the utility of titanium in diverse biomedical areas, its functional properties, mechanisms of biocompatibility, host tissue responses, and various relevant antimicrobial strategies. Future research will be directed toward advanced manufacturing technologies, such as powder-based additive manufacturing, electron beam melting and laser melting deposition, as well as analyzing the effects of alloying elements on the biocompatibility, corrosion resistance, and mechanical properties of titanium. Moreover, the role of titania nanotubes in regenerative medicine and nanomedicine applications, such as localized drug delivery system, immunomodulatory agents, antibacterial agents, and hemocompatibility, is investigated, and the paper concludes with the future outlook of titanium alloys as biomaterials.Graphic abstract

Influence of Oxidation Temperature on Structure and Mechanical Properties of Titanium

Surface oxidation of pure titanium was performed in the atmosphere to increase the mechanical properties. The effect of oxidation temperature (650-900°C) for 2 h on the microstructure, composition, and mechanical properties of the treated samples was investigated using X-ray diffraction, hardness tester and indentation modulus tester, respectively. The diffusion rate of oxygen in grade-2 pure Ti with different processing temperatures discussed in present research. Based on a result of the examination, the surface hardness was increased first and then decreased as the processing temperature increased. And when the processing temperature at 850°C, the surface hardness reached the maximum value. In addition, the Young's modulus of the treated samples also showed a maximum value of 198.9 GPa for a processing temperature of 850°C. An oxidation condition of 850°C is considered optimal as it provides sufficiently high hardness during practical use.

Прочность и механизм разрушения при кручении технически чистого титана с ультрамелкозернистой структурой

The mechanical behavior and the mechanism of torsional fracture of medical grade titanium Grade4 with an ultrafine-grained (UFG) structure in comparison with a coarse-grained (CG) structure were investigated. CG titanium (dav = 25 μm) was investigated in the hot-rolled state. To obtain the UFG structure, two processing regimes were used. In the first regime, homogenization annealing was carried out at a temperature of 680°C for 1 hour, then equal-channel angular pressing (6 passes) according to the “Conform” scheme (ECAP-С) at a workpiece and tool temperature of 250°C (route Bc, φ =120°). The average grain size is equal to 0.4 μm. In the second regime, after homogenization annealing and six ECAP-C passes, the workpieces were drawn at a temperature of 200°C (ECAP-C+D). The average grain size is equal to 0.2 μm. The torsion test of samples with a diameter of 3 mm (close to the diameter of screws for fixing plates in traumatology) was carried out on a KTS 403‑20‑0.5 installation in accordance with GOST 3565-80. The torque, number of revolutions and angle of twisting of the samples made from CG and UFG titanium, as well as the mechanical properties of titanium during torsion were evaluated. Torsion tests have shown that the torsional strength and the torsional yield strength of UFG titanium increase, and the relative shear decreases in comparison with similar properties of CG titanium. In addition, the mode of nanostructuring (ECAP-C+D) provides higher values of the torsional strength properties of titanium compared to ECAP-C, which is favorable from the standpoint of resistance to fracture of titanium screws by torsion. On the surface of the fractures, there are three regions differing in microrelief: the central part of the fracture, the middle (transitional) and the peripheral parts. In the central part of the fractures, the microrelief consists of equiaxed dimples and structureless areas. In the middle part, shear dimples dominate, and in the peripheral part of fractures, areas of shear dimples alternate with areas of the rubbed surface.

Effect of carbon on microstructure and mechanical properties of titanium

The microstructure and mechanical properties of cold rolled titanium with 0.0, 0.1 and 0.2 wt.% of carbon were studied after annealing in a temperature range of 500-800 °C. The addition of carbon resulted in slower grain growth kinetics and less intensive softening during annealing of the cold rolled alloys in the temperature range 500-800 °C. Besides, the alloys with carbon are considerably stronger in comparison with pure titanium; cold rolling resulted in an increase in the yield stress from 540 MPa for titanium to 630 and 605 MPa for Ti-0.1C and Ti-0.2C, respectively. However, ductility of the carbon doped titanium was also found to be decreased to ∼32% in comparison with 40% for pure titanium.

Effects of Reinforcement Ratios and Sintering Temperatures on the Mechanical Properties of Titanium Nitride/Nickel Composites.

In this study, powder metallurgy was used to fabricate titanium nitride/nickel metal-matrix composites. First, titanium and nickel powders with weight ratios of 20:80, 50:50 and 80:20 were dry mixed for 24 h. After cold isostatic pressing, the green compacts were soaked in a water-based hot forging lubricant and sintered at 850, 950 and 1050 °C for 1.5 h in an air atmosphere. The effects of the amounts of titanium powder and the sintering temperatures on the mechanical properties (hardness, wear resistance and compressive strength) of the composites were investigated. The results indicated that titanium gradually transformed into titanium nitride near the surface after sintering due to the carbothermal reduction reaction; this transformation was observed to significantly increase the hardness. In addition, an oxygen-rich film was observed to form between the titanium nitride particles and the nickel matrix. An optimum sintering temperature of 950 °C provides the composites (titanium–nickel weight ratios of 20:80) the best mechanical properties (wear resistance and compressive strength) among other groups. Furthermore, increasing the titanium content to 80% in the composite increased the hardness; however, the wear resistance and compressive strength decreased.

Structures and energetics of semicoherent interfaces of precipitates in hcp/bcc systems: A molecular dynamics study

α/β (hcp/bcc) interfaces are of great importance in the microstructure development and the mechanical properties of titanium and zirconium alloys. This work contributes to the study of interface energetics and interfacial structures of the precipitate in the hcp/bcc system based on a simulation study using molecular statics (MS) and molecular dynamics (MD). The input orientation relationship (OR) was calculated based on the O-line criterion. Based on the energy of the interfaces containing the invariant line (IL), two preferred facets were determined by the Wulff construction, which explained the observed orientations of the habit plane (HP) and the side facet (SF). The deviation of the observed precipitate morphology from the equilibrium shape was discussed in terms of interface kinetics. The structures of the interfaces surrounding a three-dimensional (3D) precipitate, including the preferred facets and the end face, were obtained at the atomic level. The simulated dislocation structures and atomic structures in these interfaces are in good agreement with those of the experimental observations for Ti-Cr alloys. A method was suggested for modifying the O-cell structure with the guidance of the relaxed structure, yielding consistency between the calculated dislocation structure based on the generalized O-element approach and the simulation results.

Electrochemical and in vitro bioactivity behavior of poly (ε-caprolactone) (PCL)-gelatin-forsterite nano coating on titanium for biomedical application

In this study, in order to improve the biological, chemical, and mechanical properties of titanium, poly (ε-caprolactone) (PCL) - Gelatin (Gel) - forsterite nano composite coating is performed on the titanium substrates. First, a uniform suspension of PCL-Gel-forsterite nano composite was prepared and then, titanium substrates were dip coated in it and then an individual nanofiber coating was employed on the first layer coating via electrospinning method. The characterization of PCL-Gel-forsterite nano composite coated samples was determined through scanning electron microscopy (SEM), X-ray diffraction (XRD). The outcome indicates a uniform nanofibrous coating containing 2 wt % forsterite nanoparticles and various amounts of the PCL were produced. The corrosion resistance of the ceramic-polymer nano fibrous coating was investigated in phosphate buffered saline solution (PBS) using electrochemical impedance spectroscopy (EIS) and it is proved that the nanofibrous coating significantly improve the corrosion resistance of the titanium substrate. At the end the cellular responses of produced nanofibers to MG63 cells were evaluated and cell viability results showed that bioactivity improved with decreasing GEL content confirming the potential application of PCL-Gel-forsterite nanofibrous composite coating for biomedical applications.

Effect of α-lath size on the mechanical properties of Ti–6Al–4V using core time hydrogen heat treatment

ABSTRACTWhen hydrogen is dissolved, brittleness occurs in the material. However, in the case of titanium and titanium alloy, hydrogen can be temporarily dissolved and removed, thereby improving the mechanical properties of titanium and titanium alloy. In this study, Core time Hydrogen Heat treatment (CHH) applies to Ti–6Al–4V alloy to improve mechanical properties. CHH was performed at 800°C and 1000°C for 2 h. Thereafter, dehydrogenation was performed for 2 h at 700°C in vacuum atmosphere to remove residual hydrogen. After the CHH at 800°C, it was found that the α-lath size in the Ti–6Al–4V was narrowed; thereby increasing the Vickers hardness and tensile strength without decreasing in elongation.

Fatigue of Narrow Dental Implants: Influence of the Hardening Method.

The use of narrow titanium dental implants (NDI) for small ridges, reduced interdental space, or missing lateral incisors can be a viable option when compared to the conventional wider dental implants. Furthermore, in many cases, standard diameter implant placement may not be possible without grafting procedures, which increases the healing time, cost, and morbidity. The aim of this study was to analyze the mechanical viability of the current narrow implants and how narrow implants can be improved. Different commercially available implants (n = 150) were tested to determine maximum strength, strain to fracture, microhardness, residual stress, and fatigue obtaining the stress–number of cycles to fracture (SN) curve. Fractography was studied by scanning electron microscopy. The results showed that when the titanium was hardened by the addition of 15% of Zr or 12% cold worked, the fatigue limit was higher than the commercially pure grade 4 Ti without hardening treatment. Grade 4 titanium without hardening treatment in narrow dental implants can present fractures by fatigue. These narrow implants are subjected to high mechanical stresses and the mechanical properties of titanium do not meet the minimal requirements, which lead to frequent fractures. New hardening treatments allow for the mechanical limitations of conventional narrow implants to be overcome in dynamic conditions. These hardening treatments allow for the design of narrow dental implants with enhanced fatigue life and long-term behavior.

Zirconia versus titanium in dentistry: A review.

This review scientifically compares the properties of zirconia and titanium, but does not identify the best among them as an implant material. Surface treatment and modification to improve tissue bonding and inhibit bacterial adhesion are not considered in this review. The mechanical properties of titanium are superior to those of zirconia; some studies have shown that zirconia can be used as a dental implant, especially as an abutment. Extensive surface treatment research is ongoing to inhibit bacterial adhesion and improve osseointegration and soft tissue adhesion phenomena which make it difficult to evaluate properties of the materials themselves without surface treatment. Osseointegration of titanium is superior to that of zirconia itself without surface treatment; after surface treatment, both materials show comparable osseointegration. The surface morphology is more important for osseointegration than the surface composition. To inhibit bacterial adhesion, zirconia is superior to titanium, and hence, more suitable for abutments. Both materials show similar capability for soft tissue adhesion.

Влияние мегапластической деформации в камере Бриджмена на фазовые превращения, коррозионное поведение и микротвердость титана марок ВТ1-00 и ВТ1-0

Due to the combination of lightness, high specific strength and corrosion resistance, titanium and its alloys are highly interesting for applying in many areas of industry (mechanical engineering, shipbuilding, and aircraft manufacturing). Technically pure titanium is the first choice to be used in medicine because of its high biocompatibility and lack of toxic elements. Pure titanium has high ductility and corrosion resistance but it is inferior to titanium alloys in other mechanical characteristics, such as tensile strength, yield strength, and hardness. Megaplastic deformation (MPD) is a promising method for increasing the strength of titanium to the level of highly alloyed alloys. The paper deals with the study of the influence of MPD in the Bridgman chamber on the structure (phase transformations occurring in technically pure VT1-00 and VT1-0 titanium), corrosion resistance, and microhardness. Using the high-pressure torsion (HPT), the authors obtained samples with different degrees of deformation: from 0.25 to 4 revolutions of the movable anvil. The authors carried out the X-ray diffraction analysis and electrochemical tests of samples and studied the phase composition of titanium samples of two grades containing 0.1 and 0.3 % of impurities before and after MPD. The study identified that the HPT led to the formation of a two-phase mixture a+ɷ. The results showed the positive effect of MPD on the mechanical properties of titanium. The microhardness of the deformed material increases in comparison with the initial state, while there is no deterioration in the corrosion resistance in the studied environment. Under all deformation modes, titanium stays in a passive state. For the VT1-0 alloy, the stationary corrosion potentials of samples after HPT have a more positive value compared to the original undeformed material.