Use Of Titanium Alloys Research Articles

Laser Cutting of Titanium Alloy Plates: A Review of Processing, Microstructure, and Mechanical Properties

The growing use of titanium alloys has led to the gradual replacement of traditional processing methods by laser cutting technology, making it the preferred method for processing titanium alloy plates due to its high efficiency, precision, and adaptability. In this review, the characteristics of laser cutting technology and its application in titanium alloy plate processing are summarized, outlining several aspects of the cutting process, microstructure, and mechanical properties of the material after cutting, along with simulation predictions. Previous research categorized laser-cutting input parameters into beam parameters and process parameters, with the commonly used parameters being the laser power, cutting speed, and gas pressure. Various parameter combinations can achieve different cutting qualities, and seven indices can be used to evaluate the cutting process, with the surface roughness and slit width serving as the most common indices. Different auxiliary gases have shown a significant impact on the laser cutting quality, with commonly used gases consisting of nitrogen, argon, and air. Argon-assisted cutting generally results in better surface quality. Due to the rapid temperature change, the titanium alloy microstructure will undergo a non-diffusive martensitic phase transformation during laser cutting, producing a heat-affected zone. Experimental studies and simulations of the mechanical properties have shown that the occurrence of a martensitic phase transformation increases the hardness and residual tensile stress of the material, which reduces the fatigue strength and static tensile properties. In addition, studies have found that the more streaks appear on the cut surface, the lower the fatigue strength is, with fatigue cracks arising from the stripes. Hence, the established analytical solution model and three-dimensional finite element model can effectively predict the temperature distribution and residual stress during the cutting process. This can provide a better understanding of the high residual stress characteristics of the cutting edge and the stripe formation mechanism, allowing researchers to better explore the mechanism of laser cutting.

Wear and corrosion resistance behavior of hydrophobic surface on Ti-6Al-4V prepared by nitrogen gas-assisted EDM

Despite the widespread use of titanium alloys in various fields, surface defects that arise during the processing of Ti-6Al-4V can significantly reduce their service life. Therefore, developing a new approach to enhance the performance of TC4 alloys, particularly in challenging environments such as high-wear and wet conditions is crucial. This study proposes a novel method to create a hardened surface enriched with TiN using nitrogen gas-assisted electrical discharge machining (NA-EDM). The aim was to assess the impact of surface modification via NA-EDM on anti-wear and anti-corrosion performance across different peak currents and to explore the mechanism behind the surface's hydrophobic properties. The findings show that the NA-EDM process produces fewer surface defects compared to traditional EDM. Moreover, NA-EDM treatment significantly improves surface hydrophobicity, as evidenced by a 21.25 % increase in the contact angle (CA). Furthermore, the NA-EDM-treated surface exhibits enhanced resistance to wear and corrosion, with a notable 14.9 % reduction in wear rate and average friction coefficient.

Study of different cutting fluids effect on the coupling characteristics of milling noise-vibration and surface roughness of TA2 pure titanium

With the increasing use of titanium alloys, it is essential to improve cutting efficiency. However, there are various problems such as high noise, strong vibration and difficulty to control the surface finish quality in actual cutting process, which can be more serious with the increase of machining parameters. In order to obtain better machining quality and higher efficiency, the influence of cutting parameters and cutting fluid on the milling process of TA2 pure titanium under two cutting conditions that use different cutting fluid is firstly studied in this paper. The correlation between the surface roughness (SR) of the workpiece and multiple metrics which milling noise (MN) and milling vibration (MV) is further studied on the basis of experimental data. In this paper, a series of parameters that have a strong correlation with SR are selected. Then, prediction models based on Least Squares Method (LSM) and Response Surface Methodology (RSM) are established. Finally, established models are compared to find ways to improve prediction accuracy. The experimental results indicate that compared with water-based cutting fluid, oil-based cutting fluid can make TA2 workpiece obtain better and more stable cutting performance most of the time; MV has a more significant correlation with SR and is therefore more suitable for establishing prediction model; The accuracy of the prediction model that takes the multi-factor coupling effect into consideration has been generally improved and the average optimization degree of the Improved Particle Swarm Optimization (IPSO) algorithm for LSM is 2.91 %, which has good optimization performance.

Revealing High-Temperature Oxidation and Tensile Behaviors along with Underlying Mechanisms of a Titanium Alloy with Precipitated Titanium Silicide

Titanium alloys, with their impressive strength relative to their weight, resistance to corrosion, and compatibility with biological systems, have found extensive applications in various industries. In high-temperature environments, especially within the aerospace sector, it is essential to advance titanium alloys that boast enhanced resistance to oxidation and superior mechanical characteristics. This work investigates the oxidation characteristics and mechanical performances at high temperatures of a titanium alloy with titanium silicide particles. Oxidation at temperatures of 600–700 °C over a span of 8–32 h led to the formation of protective oxide layers and moderate oxidation rates. However, accelerated oxidation and oxide spallation occurred after exposed at 800 °C for a period of 16 h, indicating inadequate oxidation resistance over 800 °C. Subsequent tensile tests at 650 °C revealed intricate dislocation patterns in the α-Ti matrix and their strong interaction with interfaces of α-Ti/Ti5Si3, which is indicative of an efficient load transfer between the precipitates and the matrix. Overall, this study offers fresh perspectives on the oxidation kinetics and the deformation processes of titanium alloys with in-situ Ti5Si3 particles at high temperatures. These insights will guide subsequent alloy development endeavors aiming to broaden the use of titanium alloys in increasingly challenging high-temperature settings.

To the selection of shock absorber elements of the artificial foot

Introduction. Walking on a prosthesis of the lower limb is accompanied by a shock load on the artificial foot, which provokes discomfort when using the product and pain in the stump, increases the risk of trauma to the skin and the formation of arthrosis of the joints of the lower limb. These negative consequences can be reduced by the use of prosthetic modules with shock-absorbing properties. Usually, the artificial foot plays the role of a shock absorber in the prosthesis.Aim – substantiation of the choice of material for the shock-absorbing module of the artificial foot.Materials and methods. Bench tests of leaf springs made of steel, carbon and titanium alloy of different thicknesses were carried out by registering changes in their geometric characteristics under a dosed load, as well as full-scale tests of experimental artificial feet with such springs used as a load absorber. The functionality of the feet was determined by the subjective assessment of the comfort of the prosthesis by the patient and the result of the analysis of pressure dynamics under the feet. Results. The results of bench tests showed that leaf springs made of steel 2 mm thick, titanium alloy 3 mm and carbon fiber (carbon) 5.7 mm are unsuitable for use as a shock absorber in the foot of the prosthesis in terms of deflection in the longitudinal and transverse directions under load, in contrast to springs made of 3 mm steel and 4 mm titanium alloy. Field tests of experimental feet with shock-absorbing modules made of steel 3 mm thick and titanium alloy 4 mm showed their suitability for use as part of a prosthesis, which was confirmed by a positive assessment of their comfort by patients, as well as an increase in the symmetry coefficient of the duration of the roll over the artificial and intact feet when walking with experimental foot design compared to industrially manufactured.Discussion. The 4mm titanium alloy leaf spring outperforms the 3mm steel spring in terms of buckling under load, but biomechanical studies have not shown a clear preference for the experimental foot with one of these materials over the other. At the same time, each of them turned out to be more functional than the commercially manufactured foot chosen for the study. But the high corrosion resistance and low specific gravity of the titanium alloy, higher mechanical strength per unit mass compared to steel, give advantages to this material for the manufacture of shock-absorbing modules in atypical prostheses. The choice of the thickness of the elastic element can and should be calculated taking into account the weight of the disabled person.Conclusion. The manufacture of elastic elements from titanium alloys is promising when used in artificial feet for atypical prostheses that require high corrosion resistance and mechanical strength with a small mass of the product. A positive factor in the use of titanium alloys for the manufacture of foot shock absorbers in the form of leaf springs is the simplicity and low cost of the design.

Defect microstructure of a Ti64 alloy under TI2+ ion irradiation. Influence of dose and temperature

The present paper focuses on the microstructural changes in Ti64 alloy after irradiation. The titanium alloys allow a significant decrease in activation and mass with a similar mechanical strength and a similar corrosion resistance than 304 stainless steels, widely used for core internal structures of Pressurized Water Reactors. The use of titanium alloys could be therefore a significant improvement for reactor exploitation and decommissioning. The nature, size and density of the radiation-induced defects are likely to be important parameters governing the in-reactor behavior of the material. The aim of the study was to devise new achievements in thin foil preparation and Transmission Electron Microscopy (TEM) imaging in order to accurately identify and quantify the Ti64 irradiation defects, at temperatures representative of irradiation temperatures in a reactor. The method to image and count the precipitates was developed with samples irradiated by ions at the temperature of 600 °C. Indeed, the microstructure of the sample irradiated at 600 °C was characterized by a low density of tangled dislocations, and big precipitates, that were easily evidenced. Then the process was applied in samples irradiated with ions at 430 °C and 300 °C characterized by a microstructure of tangled dislocations, loops and small precipitates. In 430 °C irradiation condition, the measurement in dark field with a B∼[11–23]α orientation and with a high magnification micrograph provided similar results than Atom Probe Tomography (APT) analyses. In irradiation condition at 300 °C, the precipitates were imaged by TEM as soon as the dose of 1 dpa. However they were not observed at the dose of 0.4 dpa. The precipitates were so small and their density was so high that the measurement by TEM was very imprecise and APT analyses were needed. The results of this microstructural analysis allowed a discussion on the nucleation mechanism of the irradiation defects in Ti64 alloy.

The tribological properties of two-phase hard and soft composite wear-resistant coatings on titanium alloys

There are still problems associated with the use of conventional modified coatings on titanium alloys despite their attempts to improve wear resistance. These problems include incompatibility of mechanical properties, a poor interface bond, and an abundance of debris. The development of wear-resistant coatings with high reliability and long life is a vital component of expanding the use of titanium alloy in medical implants. The purpose of this study was to produce a composite coating with antifriction and wear-resistant properties by combining the high hardness TiN layer with the soft phase lubricated Cu layer produced by ion implantation and electroless plating. The implantation of Cu ions provided the nucleation sites for electroless copper plating and improving interfacial bonding. There was a reduction in adhesive wear due to the composite coating. By comparing the tribological test results of the composite coating and substrate, the volume loss of coatings decreased by 95 % for the same sliding length, the wear rate decreased from 2.55 × 10−13 m3/N·m to 1.28 × 10−14 m3/N·m, the friction coefficient reduced by 10 % and smoother. As a result of the synergistic effects between the soft and hard phases in the composite coating, titanium alloy exhibited an enhanced wear resistance as the wear process progressed.

Atomisation of Ti-6Ta-1.5Zr-0.2Ru-5Cu (wt%) for additive manufacturing for biomedical applications

The use of titanium alloys is growing fast as people have longer life expectancies and small, customised, biomedical implants, especially in dental applications, encourage the use of additive manufacturing (AM) to shape them. The Ti-6Ta-1.5Zr-0.2Ru-5Cu (wt%) alloy has been identified as a potential alloy for biomedical applications. Since laser powder bed fusion (L-PBF) requires starting powders to be spherical and within a 10-100 μm size range, the Ti-6Ta-1.5Zr-0.2Ru-5Cu (wt%) powder was ultrasonically atomised and then analysed by a Malvern Mastersizer, XRD and SEM-EDX to ascertain that it met the requirements of L-PBF.

Мікроструктура поверхневого шару титанового сплаву модифікованого вакуумним іонним азотуванням в імпульсному режимі

The mechanical strength and durability of structural elements is ensured by the correct selection of the materials from which they are made and the special functional properties of the surface layer, which are provided by applying coatings or by changing the structural state of the surface layers of the material by means of their modification. The use of titanium alloys provides unique properties, including high specific strength, corrosion resistance and a fairly high melting point. However, the use of these materials is limited by their low hardness, extremely low wear resistance, high tendency to sticking, high coefficient of friction in pairs with almost all materials, high chemical activity during heating above 500ᵒС and sensitivity to stress concentrators. To reduce the disadvantages of titanium alloys, various technological processes of strengthening are used by modifying the surface layers: by implantation of ions of various metals; surface treatment with concentrated energy flows; plasma flows; surface plastic deformation; ultrasonic treatment; laser processing; diffusion saturation and chemical-thermal treatment. Of all the modification methods, such a method of HTO as nitriding has become the most widespread, however, it involves long-term high-temperature heating, which causes fragility of the obtained nitrided layers, leads to a change in the metal structure and a decrease in strength characteristics. Task statement: conduct metallographic studies of the microstructure of modified surfaces with determination of the structure and depth of saturation of the diffusion layer with nitrogen Microsands for metallographic studies were produced on the "Alpha & Beta" installation (manufacturer of TM BUEHLER) according to the standard method (preventing tempering and overheating) with subsequent detection of the microstructure by chemical etching in a herbarium: НNO3 : HF : H2O (7 ml. : 2 ml. : 50 ml.). Metalohrafichni doslidzhennya zrazkiv provodyly v pozdovzhnʹomu peretyni po tovshchyni na optychnomu invertovanomu mikroskopi «AXIOVERT 40 MAT» z fiksatsiyeyu mikrostruktur tsyfrovoyu fotokameroyu AXIOCAM 305 v prohrami «ZEN core v3.1» Yak pokazaly doslidzhennya, tovshchyna nitrydnoho sharu pry vakuumnomu ionnomu azotuvanni v impulʹsnomu rezhymi tytanovoho splavu VT1-0 skladaye ne bilʹshe 1520 mkm, pid yakym znakhodytʹsya zona vnutrishnʹoho azotuvannya menshoyi tverdosti, yaka postupovo zmenshuyetʹsya po eksponentsiyniy zalezhnosti do tverdosti osnovy. Metallographic studies of the samples were carried out in a longitudinal cross-section by thickness on an optical inverted microscope "AXIOVERT 40 MAT" with fixation of microstructures by a digital camera АXIOCAM 305 in the program "ZEN core v3.1". As the studies showed, the thickness of the nitride layer during vacuum ion nitriding in the pulse mode of titanium alloy VT1-0 is no more than 1520 μm, under which there is a zone of internal nitriding of lower hardness, which gradually decreases exponentially depending on the hardness of the base. The structure of the base material does not change during low-temperature nitriding. A nitrided layer is formed on the surface with a nitride zone of varying thickness, which depends on the mode of nitriding and is weakly etched by the herbarium. The microstructure of the samples is an equiaxed polyhedral structure of the α-phase with a liquation band in the axial zone. Microhardness was determined under a load of 50, 100, and 200 g. The holding time under the load was 10 seconds. Microhardness was measured on the sandpapers in the radial direction of the segment with a step of 0.05 mm. The load depended on the dispersion and thickness of the reinforced layer. Conclusions. Nitriding (up to 900ᵒС) in the glow discharge of titanium VT1-0 and VT1-00 allows to significantly increase the microhardness due to the properties of nitrogen and its compounds with titanium, while preserving the original mechanical properties of the base material. A change in the parameters of the nitriding process (temperature, pressure, composition of the saturating medium and nitriding time) causes a change in the physical and mechanical characteristics, structure, thickness, phase and chemical composition of the surface nitriding layer: microhardness of the surface up to 10500 MPa; the thickness of the nitrided layer is up to 500 microns; the thickness of the nitride layer is up to 25 microns; phase shift difference TiN, Ti2N, Ti(N); different gradient of hardness in depth, which allows to optimize the power of the surface of the ball in specific conditions of operation.

A Review of the Use of Titanium for Reinforcement of Masonry Structures.

Titanium has exceptional durability, very high specific strength, a thermal expansion coefficient similar to construction materials, low weight density, and its cost has drastically decreased over the last decades. One of the main requirements in conservation engineering is the durability of the retrofit materials and the reversibility of interventions, and a possible interesting solution is the use of titanium alloys coupled with inorganic matrices made of low-cement or lime mortars. Titanium has recently been used to reinforce important masonry and archeological monuments, but little is known about this. Its use is increasing in conservation engineering without adequate knowledge of its characteristics, grades, and properties. This paper summarizes the main features of titanium alloys, its recent applications, and discusses its drawbacks and advantages compared to other retrofit materials and methods. It is demonstrated that titanium alloys can be effectively used in many applications to reinforce masonry structures while complying with requirements in terms of durability, compatibility, and reversibility. Given its mechanical properties, its use in the repair and reinforcement of masonry structures could be particularly interesting in seismically prone areas.

Design of Low-Cost and High-Strength Titanium Alloys Using Pseudo-Spinodal Mechanism through Diffusion Couple Technology and CALPHAD.

The high cost of development and raw materials have been obstacles to the widespread use of titanium alloys. In the present study, the high-throughput experimental method of diffusion couple combined with CALPHAD calculation was used to design and prepare the low-cost and high-strength Ti-Al-Cr system titanium alloy. The results showed that ultra-fine α phase was obtained in Ti-6Al-10.9Cr alloy designed through the pseudo-spinodal mechanism, and it has a high yield strength of 1437 ± 7 MPa. Furthermore, application of the 3D strength model of Ti-6Al-xCr alloy showed that the strength of the alloy depended on the volume fraction and thickness of the α phase. The large number of α/β interfaces produced by ultra-fine α phase greatly improved the strength of the alloy but limited its ductility. Thus, we have demonstrated that the pseudo-spinodal mechanism combined with high-throughput diffusion couple technology and CALPHAD was an efficient method to design low-cost and high-strength titanium alloys.

Formation Ti6Al4V alloy by hydride cycle mode and its (Ti6Al4V)H1.606 hydride in self-propagating high-temperature synthesis mode

The wide use of titanium alloys is limited by high costs of both their producing technology and processing. The expansion of area of their application depends on development of more efficient, resource-saving, economical methods providing reduction in the cost of titanium alloys and titanium made products. The hydride cycle (HC) method for synthesis of binary and multicomponent refractory alloys and hydrides can be suitable alternative to traditional metallurgy for production of the alloy in small quantities (small-sized products for technical/medical purposes). This work presents the results of study on the mechanism of Ti–6Al–4V alloy formation in HC. The synthesis parameters are evaluated and optimized. The physicochemical, structural and hydrogen-sorption characteristics of the alloy samples are described. Actually, a resource-saving, efficient technology for synthesis of Ti–6Al–4V alloy by HC is developed and proposed. The synthesized alloy interaction with hydrogen in Self-Propagating High-Temperature Synthesis mode was investigated.

Application of sodium chloride as space holder for powder injection molding of alloy Titanium–Hydroxyapatite composites

The development of porous metal structures, especially for the use of titanium alloys in bone implant applications, has attracted the attention of researchers. However, forming porous structures in titanium composites via powder injection molding (PIM) remains in the early stages of analysis, allowing the determination of processing parameters to be studied in greater detail. In this study, the critical PIM parameters for processing porous alloy titanium–hydroxyapatite composites were identified via the space holder method. Titanium alloy (Ti6Al4V) was mixed with hydroxyapatite (HA) at a weight percentage ratio of 9:1 with 20 wt.% sodium chloride (NaCl) as the space holder. Feedstock was prepared by combining the powder with a binder system. Pseudoplastic flow activity, which was the desired rheological property needed for PIM, in the feedstock was determined. A tensile bar specimen was successfully injected with a green strength of 2.92 MPa. The space holder was then removed via water leaching, whereas the binders were removed by a debinding step before being sintered in a high-vacuum condition for 3 h at 1350 °C. The sintered parts were interconnected and had a porosity level of 37.03%. Energy dispersive X-ray mapping revealed that the porous titanium–hydroxyapatite composite contained titanium (Ti), calcium (Ca), phosphorus (P), and oxygen (O) components. This study indicated that the combination of PIM and the space holder method is a promising technique for manufacturing near net-shaped porous titanium–hydroxyapatite composites.

Application of Titanium Alloy and Titanium-Based Coatings in a Gate Valve during Oil Production

In the Caspian region, the Tengiz oil field has a high content of sulfur, salts and mechanical impurities, which contribute to the rapid deterioration of equipment. The use of titanium alloy allows reducing corrosion wear 2-3 times. Based on the analysis of the design of the slide gate valve, the most exposed parts were identified, which were replaced by Grade 5 titanium alloy. Bench tests of the slide gate valve were put into operation. Laboratory work was carried out to apply titanium-based coatings to steel samples. The result was a structure with a microhardness of 730-810 HV sufficient to protect it against corrosion wear.

ДОСЛІДЖЕННЯ ПИТАННЯ ВПРОВАДЖЕННЯ АДИТИВ-НИХ ТЕХНОЛОГІЙ В АВІАБУДІВНУ ГАЛУЗЬ

The article deals the issues of improving the quality, reducing time, cost of manufacturing domestic aircraft and reducing their weight by modernizing technological processes taking into account a wide range of functionalities for the use of additive technologies for the production of structural elements of aircraft from titanium alloys. The article provides is determined that titanium and its alloys, due to their unique chemical and mechanical characteristics, continue to be relevant and in demand metal used in the construction of modern aircraft. But traditional methods of manufacturing parts made of titanium are high cost and do not allow the use of this metal in large quantities. The solution proposed to this problem is the use of additive manufacturing technologies for the manufacture of aircraft structural elements from titanium. Data are given about of the use of titanium alloys in the aerospace, automotive, biomedical and chemical industries due to the excellent combination of strength, low density, as well as very high corrosion resistance and fatigue strength are given. The efficiency of using titanium alloys for the manufacture of structural elements of aircraft in terms of reducing the total weight of the aircraft and high reliability of the structure as a whole. The article provides descriptive information about additive technologies in mechanical engineering. The review of works of foreign scientists concerning research of differences in mechanical characteristics, microstructure and macrostructure of samples made by means of additive technologies is resulted, their advantages and lacks are noted. The list of advantages of additive technologies in mechanical engineering which cause economic efficiency from their use is resulted. Attention is drawn to the most common methods of additive production: substrate synthesis (PBF), direct energy and material supply (DED). It is given the tasks of research are defined and the decision of optimization of technology of manufacturing of elements of a design of aircraft. Research will further improve the technology of aircraft production.

Drastic improvement in elongation and impact toughness of Ti–Al–V–Mo–Zr alloy tube via three-step heat treatment

The limited ductility and impact toughness of titanium alloys is a critical issue that limits the use of titanium alloys in the oil and gas industry. In this study, we obtained the highest impact toughness (55.7 J/cm2) for an extruded Ti–Al–V–Mo–Zr alloy tube using a three-step heat treatment. The microstructure and corresponding mechanical properties of the Ti–Al–V–Mo–Zr alloy tube were studied. We achieved significantly improved elongation (69%) and impact toughness (51%) of the Ti–Al–V–Mo–Zr alloy, contribute to the mixing coarse equiaxed and lamellar microstructure. The special heat treatment and bending lamellar microstructures play an important role in this significant phenomenon.

Experimental and numerical investigations of the heating influence on the Ti5553 titanium alloy machinability

The use of titanium alloys has become more widespread in recent years. Regardless, although research work is enhancing, productivity levels remain low. Several alternatives have been considered and one of the techniques is envisaged is heating assistance. The objective is then to increase the temperature locally in order to benefit from thermal softening. However, the research is based on power-controlled laser assistance where the temperature levels are not considered. For this purpose, this article suggests a study based on a new experimental device which allows to control the temperature of the machined part. After presenting the device and the material used (Ti5553), the study first shows the effect of temperature on cutting forces. Three temperature ranges and three trends are shown. A first where temperature has no effect, a second when there is a substantial gain and a third where temperature has a real impact. In order to understand the existing links, two methods were used. A finite element model integrating a new law of behaviour was developed and shows the very high temperature levels reached in the cutting areas. Then, to better understand the phenomena governing cutting, we looked at chip formation and the link between chip formation, temperature and its effect on the microstructure. After all, an economic analysis completes this article and highlights the small gains of this assistance.

Influence of welding process on the properties of dissimilar titanium alloy weldments: a review

The extensive use of titanium alloys in a variety of complex industrial applications may be attributed to their properties of high strength-to-weight ratio, corrosion resistance and high temperature strength. Recently, the use of dissimilar titanium alloys has become popular to achieve contrasting characteristics in a single unit. In the fabrication of the structures, joining methods such as welding hold the key in the attainment of the desired characteristics. The present study is aimed at reviewing various state-of-the-art processes used for welding of dissimilar titanium alloys. In particular, the influence of different welding methods such as gas tungsten arc welding (GTAW), laser and electron beam welding on the microstructure, mechanical properties and other characteristics of dissimilar weldments of α, α + β and β titanium alloys has been emphasized. The underlying phenomena that govern the effect of weld processing parameters on the mechanical strength, microstructure and weld joint quality of the alloys were exploited. Moreover, detailed investigations on the fusion zone porosities and evolution of intermetallic concept at the interfacial regions have been examined. Furthermore, different remedial approaches to enhance the joint quality such as beam offsetting, process hybridization, aging and post-weld heat treatments are investigated thoroughly. The latest trends in dissimilar welding of titanium alloys to upheave further research in this area have been reported in the context of their application in industrial applications.

High temperature rise dominated cracking mechanisms in ultra-ductile and tough titanium alloy

Extensive use of titanium alloys is partly hindered by a lack of ductility, strain hardening, and fracture toughness. Recently, several β-metastable titanium alloys were designed to simultaneously activate both transformation-induced plasticity and twinning-induced plasticity effects, resulting in significant improvements to their strain hardening capacity and resistance to plastic localization. Here, we report an ultra-large fracture resistance in a Ti-12Mo alloy (wt.%), that results from a high resistance to damage nucleation, with an unexpected fracture phenomenology under quasi-static loading. Necking develops at a large uniform true strain of 0.3 while fracture initiates at a true fracture strain of 1.0 by intense through-thickness shear within a thin localized shear band. Transmission electron microscopy reveals that dynamic recrystallization occurs in this band, while local partial melting is observed on the fracture surface. Shear band temperatures of 1250–2450 °C are estimated by the fusible coating method. The reported high ductility combined to the unconventional fracture process opens alternative avenues toward Ti alloys toughening.

The use of titanium alloy (F136) in surgical implants

Titanium has been widely used in the area of biomaterials, the segment of manufacture of products for rehabilitation goes through a constant evolution, because each year new techniques appear, new technologies that help in the development of biomaterials, these evolutions are mostly aimed at cost reduction, osseointegration, biocompatibility among other factors. The objective of this article is to carry out the analysis of the fixation screws of the femur prosthesis and hip prostheses, manufactured in titanium alloy ASTM 136. The use of titanium alloys in orthopedic, dental and aeronautical applications has increased in recent decades. The use of titanium in biomaterials is due to its singularities in the physiological environment and its favorable chemical and mechanical properties such as good resistance to corrosion, high degree of biocompatibility and low modulus of elasticity. For the fixation screws, analyzes of their resistance to torsion and the fracture surfaces of the tested samples were performed, for the analyzes were used Scanning Electron Microscopy (SEM) and semiquantitative analysis of the chemical elements by X-ray spectroscopy by dispersion in (EDS) and for the hip prosthesis, the fatigue test will be carried out according to ABNT NBR 7206-6. These tests aim to verify if both are able to be sold on the national market. With the tests completed, the results were compared with the standards in force. The results of the torsion tests are presented, where all samples met the quality requirements and the hip prostheses showed a stable behavior during the 10.000.000 million cycles, without failures during or after the tests.