Titanium Alloy Tube Research Articles

Design of Contact-Aided Compliant Flexure Hinge Mechanism Using Superelastic Nitinol

Abstract This paper presents a novel miniature contact-aided compliant mechanism (CCM) that includes flexure hinges and contact-aided structures. This continuum mechanism comprises a nickel–titanium alloy (Nitinol) tube with CCM cut via laser micromachining and actuated using wires bending from −80 deg to +80 deg in four directions. The proposed CCM has the following merits: perfect capacity for deflection around the centroid, a self-backbone, and improved torsional as well as tensile strengths. Further, it is pre-assembled. First, kinematic and static models are used to predict the bending behavior of the mechanism. Thereafter, the maximum strain is evaluated using finite element analysis (FEA) then compared with the static models. Finally, the performances of the mechanism are characterized by experiments. The results validate the proposed models and demonstrate that the torsional and tensile strengths of the proposed CCM increased by more than 100% and 30%, respectively, compared with those of conventional non-CCMs with a similar fatigue life. Moreover, with the integrated forceps and probe, the proposed mechanism can achieve object transfer and square trajectory scanning of the targeted location. These experimental results demonstrate the potential clinical value of the proposed mechanism and provide important insights into the design of long and flexible instruments for endoscopic surgery.

Application and Exploration of Early In-Situ Combustion Huff-and-Puff Technology in a Deep Undisturbed Reservoir with Extra Heavy Oil

Summary Achieving effective results using conventional thermal recovery technology is challenging in the deep undisturbed reservoir with extra-heavy oil in the LKQ oil field. Therefore, in this study, a novel approach based on in-situ combustion huff-and-puff technology is proposed. Through physical and numerical simulations of the reservoir, the oil recovery mechanism and key injection and production parameters of early-stage ultraheavy oil were investigated, and a series of key engineering supporting technologies were developed that were confirmed to be feasible via a pilot test. The results revealed that the ultraheavy oil in the LKQ oil field could achieve oxidation combustion under a high ignition temperature of greater than 450°C, where in-situ cracking and upgrading could occur, leading to greatly decreased viscosity of ultraheavy oil and significantly improved mobility. Moreover, it could achieve higher extra-heavy-oil production combined with the energy supplement of flue gas injection. The reasonable cycles of in-situ combustion huff and puff were five cycles, with the first cycle of gas injection of 300 000 m3 and the gas injection volume per cycle increasing in turn. It was predicted that the incremental oil production of a single well would be 500 t in one cycle. In addition, the supporting technologies were developed, such as a coiled-tubing electric ignition system, an integrated temperature and pressure monitoring system in coiled tubing, anticorrosion cementing and completion technology with high-temperature and high-pressure thermal recovery, and anticorrosion injection-production integrated lifting technology. The proposed method was applied to a pilot test in the YS3 well in the LKQ oil field. The high-pressure ignition was achieved in the 2200-m-deep well using the coiled-tubing electric igniter. The maximum temperature tolerance of the integrated monitoring system in coiled tubing reached up to 1200°C, which provided the functions of distributed temperature and multipoint pressure measurement in the entire wellbore. The combination of 13Cr-P110 casing and titanium alloy tubing effectively reduced the high-temperature and high-pressure oxygen corrosion of the wellbore. The successful field test of the comprehensive supporting engineering technologies presents a new approach for effective production in deep extra-heavy-oil reservoirs.

Analysis of anisotropy mechanism in the mechanical property of titanium alloy tube formed through hot flow forming

Anisotropy of mechanical property is an important feature influencing the service performance of titanium (Ti) alloy tube component. In this work, it is found that the hot flow formed Ti alloy tube exhibits higher yield strength along circumferential direction (CD), and larger elongation along rolling direction (RD), presenting significant anisotropy. Subsequently, the quantitative characteristics and underlying mechanism of the property anisotropy were revealed by analyzing the slip, damage and fracture behavior under the combined effects of the spun {0002} basal texture and fibrous microstructure for different loading directions. The results showed that the prismatic slip in primary α grain is the dominant deformation mechanism for both loading directions at the yielding stage. The prismatic slip is harder under CD loading, which makes CD loading present higher yield strength than RD loading. Additionally, the yield anisotropy can be quantified through the inverse ratio of the averaged Schmid Factor of the activated prismatic slip under different loading directions. As for the plasticity anisotropy, the harder and slower slip development under CD loading causes that the CD loading presents larger external force and normal stress on slip plane, thus leading to more significant cleavage fracture than RD loading. Moreover, the micro-crack path under RD loading is more tortuous than CD loading because the fibrous microstructure is elongated along RD, which may suppress the macro fracture under RD loading. These results suggest that weakening the texture and fibrous morphology of microstructure is critical to reduce the differences in slip, damage and fracture behavior along different directions, alleviate the property anisotropy and optimize the service performance of Ti alloy tube formed by hot flow forming.

Effect of Extrusion Temperature and Thermal Treatment on Microstructure and Mechanical Properties of Ti-1300 Alloy Tube

Effects of extrusion temperature and heat treatment process on the microstructure and mechanical properties of Ti-1300 titanium alloy tube billets were studied by tensile testing and microstructure observation, and the relationship among the thermal processing technique and microscopic structure and mechanical properties of the billets were also investigated. The results showed that the transverse structure of Ti-1300 alloy after extrusion in the a+b two-phase region was uniform and fine. And the longitudinal structure could be seen that the extrusion processing streamline was broken uniformly. Ti-1300 alloy extruded at a+b two-phase has a good match of the strength and ductility, and the ductility of two-phase extrusion is obviously better than that of β single-phase extrusion, especially for the reduction of area.

Modelling of the Rolling Process of Titanium Alloy Tube Billets in Laboratory Conditions on a RSP 14-40 Rolling Mill

The development of screw rolling technology for the production of hot-deformed tubes over Ø250 mm on a SVP-500 rolling mill faces a number of challenges that influence the quality of tubes, such as: the screw trace formed on the external surface of tubes and bending of tubes that makes impossible subsequent manufacturing operations. The following experimental and laboratory research was performed to solve these problems: a number of experimental tube billets with and without mandrels were rolled to various strains on a RSP 14-40 laboratory rolling mill to obtain the best ratio of wall thickness to the external diameter. The temperature field distribution and the strain intensity in the deformation area of tube billets rolling were analyzed. A quality assessment of the influence of the section of the calibrating rolls used in industrial technology on the external surface of hot-deformed tubes was also carried out at the modeling stage. The angle changing options of the calibrating rollers section of the screw rolling mill were analyzed for the subsequent tool improvement.

Model establishment of surface roughness and experimental investigation on magnetorheological finishing for polishing the internal surface of titanium alloy tubes

A novel magnetorheological polishing process is devised to polish the internal surface of titanium alloy tubes. Under the magnetic field in polishing area between the internal surface of tube and polishing head, magnetorheological polishing fluid gets stiffened and acts as the polishing tool. In this process, rotation motion of tube and reciprocating linear motion of polishing head are carried out simultaneously resulting in helical motion trajectory of abrasive particles on workpiece surface. The finishing forces during magnetorheological polishing process including normal indentation force and shear force are analyzed and modeled. Based on the proposed model, final surface roughness Ra model is proposed to predict the polishing performance. Experiments are carried out to investigate the effect of polishing time and initial surface roughness Ra on polishing performance. The experimental results are compared with the model results, which are highly consistent. The results show a gradual growth of surface precision with polishing time and an augment of polishing efficiency with increasing initial surface roughness Ra.

Influence of Texture on Mechanical Properties of Titanium Alloy Tubes

Mechanical properties and texture of tube material formed in the process of tube production were studied. Texture in tubes was estimated by contractile strain ratio (CSR) according to requirements of the standard for tubes. Mechanical properties depend on CSR. Optimal values of mechanical properties were determined: ultimate strength, yield strength and relative elongation which provide CSR values within 1.3...3.5. The texture was evaluated in the process of tube manufacture. An increase in radial component of the texture leads to an increase in CSR. At high CSR values up to 3-3.5, tubes often do not withstand process tests for flattening and bending. Correction of CSR values is required. It was shown that an increase in ductility of tubes increases the value of CSR.

Annular Surface Micromachining of Titanium Tubes Using a Magnetorheological Polishing Technique.

In this study, a novel magnetorheological (MR) polishing device under a compound magnetic field is designed to achieve microlevel polishing of the titanium tubes. The polishing process is realized by combining the rotation motion of the tube and the reciprocating linear motion of the polishing head. Two types of excitation equipment for generating an appropriate compound magnetic field are outlined. A series of experiments are conducted to systematically investigate the effect of compound magnetic field strength, rotation speed, and type and concentration of abrasive particles on the polishing performance delivered by the designed device. The experiments were carried out through controlling variables. Before and after the experiment, the surface roughness in the polished area of the workpiece is measured, and the influence of the independent variable on the polishing effect is judged by a changing rule of surface roughness so as to obtain a better parameter about compound magnetic field strength, concentration of abrasive particles, etc. It is shown from experimental results that diamond abrasive particles are appropriate for fine finishing the internal surface of the titanium-alloy tube. It is also identified that the polishing performance is excellent at high magnetic field strength, fast rotation speed, and high abrasive-particle concentration.

Enhancing hoop strength of titanium alloy tube by cross spinning

There is an increasing demand for thin-walled long tubular workpieces of titanium alloys with excellent mechanical properties, which can be produced by power spinning owing to its specific advantages over other forming processes. In this paper, a novel spinning forming process, named cross spinning (CS), was proposed to tune the hoop properties of as-spun tubular workpieces. Traditional unidirectional spinning (UDS) and CS experiments were conducted to form the tubular workpieces of Ti–6Al–4V alloy, and their mechanical properties and microstructure evolution were analyzed and compared. The tensile test indicated that both axial and tangential strengths of the CS specimens were higher than that of the UDS specimens, which was more remarkable for the tangential strength. To clarify this phenomenon, crystal plasticity finite element method (CPFEM) coupled with spinning texture information was used to simulate the tensile test for the CS and UDS specimens. The results indicated that a more homogeneous texture was formed during CS, inducing lower average Schmid factor for prismatic slip system and larger activities of the pyramidal slip systems, was the major cause for enhancing the hoop mechanical properties of the as-spun workpieces compared with that during UDS.

Influence of texture on mechanical properties of titanium alloy tubes

Influence of texture on mechanical properties of titanium alloy tubes

Deformation-based joining for high-strength Ti-3Al-2.5V tubular fittings based on internal roller swaging

Deformation-based joining presents efficient, reliable and environmentally friendly advantages widely applying in the pipeline system. Internal roller swaging (IRS), one of deformation-based joining ways, is an inner expanding spinning process with characteristics of sheet-bulk forming, and it has the potential to fabricate high-strength tubular joining components with better high-pressure resistance and sealing performance. Taking a high-strength Ti-3Al-2.5V titanium alloy (TA) tube as the case material, this study combines explicit and implicit finite element (FE) modeling with experimental validating to explore the deformation mechanisms of the IRS process. By using the digital image correlation method (DICM) based uniaxial tension, the contractile strain ratio (CSR) of the TA tube was obtained to describe its anisotropy. By analyzing the mechanism of IRS, the motion equations of three rollers were deduced in the forming process, and a simplified 3D FE model for the IRS process was developed. Based on the FE simulation and analysis, the inhomogeneous flow deformation behaviors of TA tube in the IRS process were investigated by subdividing the deformation areas of the tube. Then, the material flow features of TA tube in the IRS process were explored by analyzing the axial displacements of the tube and observing its flow localization by means of optical microscope. Finally, the forming quality of the tubular joining components can be accurately designed and controlled by revealing the relationship between the swaging depth and the axial elongation and the relationship between the swaging depth and the contact shear stress. It is concluded that this incremental deformation-based joining process has obvious superiority to fabricate high-strength TA tubular joining components, and their reliability can be effectively enhanced by accurately controlling the swaging depth.

Влияние степени деформации при холодной прокатке труб из сплава титана на формирование текстуры и свойств

Влияние степени деформации при холодной прокатке труб из сплава титана на формирование текстуры и свойств

Texture evolution and controlling of high-strength titanium alloy tube in cold pilgering for properties tailoring

Abstract As one of the preferred fabrication technologies for high-strength titanium alloy tubes, cold pilgering has unique advantages of large deformation, fine surface, and close dimensional tolerance since materials are incrementally experiencing compressive stress states dominated local loading throughout entire rolling process. However, both complex external loading history and low symmetric hexagonal close-packed (HCP) crystal structure induce heavy crystallographic reorientation of polycrystalline significantly influencing formability and performance of titanium tubular products. How to achieve a bespoken tailoring of texture related properties is still a challenge. Accordingly, taking high-strength Ti-3Al-2.5 V tubes as the case material, this study focuses on the tube texture evolution and the texture controlling guidelines for properties tailoring in cold pilgering. By coupling validated and verified three dimensional finite element (3D-FE) model and viscoplastic self-consistent (VPSC) crystal plasticity model, a macro-meso scaled computation platform is established to predict the inhomogeneous deformation flow and texture evolution during pilgering. Then the tube texture evolution characteristics along rolling process with three typical initial textures are investigated, and the correlation between texture evolution and spatial inhomogeneous deformation allocation is explored, in which the deformation history is fully featured by strain vector, viz., strain ratio α and equivalent plastic strain ee as well as ratios of wall thickness thinning to outer diameter reduction (total Q value and transient Q value). Taking the contractile strain ratio (CSR) as the most important indicator for evaluating the texture and properties, the effect of final texture features of the tube on its tensile mechanical properties is revealed, and then the texture controlling guidelines for properties tailoring of the tube are proposed. To obtain the desired near radial texture and the reasonable CSR, the different pass rolling specifications can be considerably designed to coordinate the spatial strain components based on reasonable range of total Q value and ee, then the rolling tools can be designed for further fine tuning of the transient Q value and strain ratio α.

A systematic review of effect of different welding process on mechanical properties of grade 5 titanium alloy

Abstract Welding is widely used in the final stage of the casting production and in fabricating the components for joining. The simplicity of titanium welding and its special effects on mechanical properties is therefore extremely important conditions in the case of engineering workings. The idea of this review is, to sum up the welding capability and its effects on mechanical properties of grade 5 titanium alloy tubes. It has been identified that the titanium welding is used in different fields throughout the world. The GTAW process is the best method to weld the titanium alloys.

Mandrel role in numerical control rotary draw bending process of TA18 high strength titanium alloy tube

In order to improve bent tube forming quality and limit, the reasonable mandrel parameters need to obtain during tube bending process. A three dimensional (3D) elasto-plastic finite element (FE) model of the whole process of TA18 high strength titanium alloy tube during numerical control rotary draw bending (RDB) was developed based on the FE software of ABAQUS, and its reliability was verified. Then, simulation and analysis of the mandrel role in tube numerical control RDB was carried out by using the model. The results show that the wall thinning increases and the cross section distortion decreases with increasing of mandrel extension length or mandrel diameter. The optimal range of the mandrel extension length and mandrel diameter is 0.5mm-1.5mm and 5.2372mm-5.3872mm, respectively.

Tooling design–related spatial deformation behaviors and crystallographic texture evolution of high-strength Ti-3Al-2.5V tube in cold pilgering

Cold pilgering has been considered as the preferred rolling fabrication technology for difficult-to-deform tubular materials such as high-strength titanium alloy tubes. However, the tooling geometry may induce complex deformation and significantly influence crystallographic texture which is closely related to the dimension assuring and properties tailoring of tube products. In this study, taking high-strength Ti-3Al-2.5V tubes as the case material, the tooling design–related spatial deformation behaviors and crystallographic texture evolution of tube in cold pilgering are focused. A macro-meso scaled computation platform is established by combining the three-dimensional finite element (3D-FE) model with the viscoplastic self-consistent (VPSC) crystal plasticity model to predict both the inhomogeneous macrodeformation and microtexture evolution in cold pilgering. Two basic tooling parameters in pilgering, viz., E1 representing exponent of roller groove curve and mandrel curve and E2 representing exponent of groove clearance, are chosen as the design variables. The cold pilgering under different tooling parameters are simulated and analyzed. The results show that (1) The rolling force decreases with the increase of E1 , while the effect of E2 on the rolling force is not significant, and smaller E1 and larger E2 have advantage for preventing surface defects of the tube product; (2) The E1 of 2.8 and E2 of 2.0 are more conducive to the wall thinning–dominated deformation of tube; (3) Taking the contractile strain ratio (CSR) as an indicator for characterizing crystallographic texture–related mechanical properties, the appropriate values of E1 and E2 for desirable radial texture of tube product are obtained.

Carbon films deposition as protective coating of titanium alloy tube using PIII&D system

The purpose of this work is to deposit carbon films inside titanium alloy tube of small diameter, in order to increase the corrosion resistance of its inner surface. The use of carbon films as protective coating can increase the lifetime of the tubes used in propulsion and thermal control systems of satellites. They can also inhibit the permeation of corrosive species, originated from the fuels and the cooling fluids, between the film-metal interface. Titanium alloy tube with 11 mm diameter and 150 mm length, with one side closed configuration was placed inside a vacuum chamber and pulsed to a high energy voltage. Carbon film deposition was performed by using a Plasma Immersion Ion Implantation and Deposition (PIII&D) system. The hollow cathode discharges (HCD) were produced with pulses of 2 kV, 15 A, 20 μs, and 500 Hz of repetition rate, using a RUP-6 pulser. The maximum temperature measured at the surface of tubes was about 1000 °C. The as-deposited carbon films were analyzed in terms of their microstructure, chemical composition, surface morphology and thickness. The surface characterization of the carbon films were carried out by means of Raman Spectroscopy, Field Emission Gun Scanning Electron Microscopy (FEG-SEM), Atomic Force Microscopy (AFM) and Potenciodynamic Polarization tests. The experimental results show an interesting change on the chemical structure of the as-deposited carbon films, when the deposition time varied from 30 min to 240 min, resulting in thicker and quite adhered films on the inner surface of tubes. In addition, the changes on the microstructure, seen by SEM analysis, as well as the ID/IG variation indicate that nanocrystalline graphite (NC-G) films can be deposited on the inner surface of titanium tubes by using this type of PIII&D system.

Use of Magnetic Induction to Activate a “Touchless” Shape Memory Alloy Implantable Penile Prosthesis

IntroductionWe describe a novel physiologic penile prosthesis that uses shape memory alloy properties to mimic the transition between a flaccid and erect penis using magnetic induction instead of hydraulic pressure. AimTo evaluate the parameters of magnetic induction to activate a shape memory alloy implantable penile prosthesis. MethodsWe prototyped an implantable penile prosthesis cylinder using temperature-tuned nickel titanium alloy tubes laser cut to specifications.The device was then tested implanted in an animal tissue model and in cadaveric tissue. Testing consisted of placing the device deactivated in its more malleable and compressed state, then activating it using an external inducer wand while measuring temperature changes that occur on the surface of the device, within the tissue, and at the skin surface. Main Outcome MeasuresOur main outcome measures were the efficiency of activation and thermal safety of this approach. ResultsUsing a handheld magnetic inductor, we were able to successfully activate the SMA penile prosthesis with no direct contact under 45 seconds. This handheld wand produced a magnetic field that penetrated tissue and caused the appropriate phase change within the prosthesis. Tissue temperature (middle and surface probes) in the animal tissue model increased only a few degrees Celsius during the activation process, and never exceeded 28 degrees Celsius from a baseline at room temperature ∼ 25 degrees Celsius. We encountered similar results without a notable change in tissue temperature in the cadaveric tests. The fully activated device resisted buckling forces of 2.66 kgf ± 0.045. Clinical ImplicationsThis non-hydraulic shape memory prosthesis obviates the needs for reservoirs and pumps, and the wand-based interaction with the device may be easier to use. Strength & LimitationsThis technology represents a fundamental departure from the hydraulic-based penile prosthesis and has comparable mechanical properties as current-marked devices. It appears to show thermal safety in controlled environments, however real-world use would need further studies. Further optimization of prototypes needs to be done prior to human clinical trials. ConclusionA shape memory penile prosthesis is a promising alternative to hydraulic-based penile prostheses and can be activated safely and efficiently using magnetic induction in our models of the human penis.Le BV, McVary KT, McKenna K, et al. Use of Magnetic Induction to Activate a “Touchless” Shape Memory Alloy Implantable Penile Prosthesis. J Sex Med 2019;16:596–601.

The experimental determination of cutting forces in a cutting zone during the orthogonal turning of a GRADE 2 titanium alloy tube

The experimental determination of cutting forces in a cutting zone during the orthogonal turning of a GRADE 2 titanium alloy tube

Stress Analysis and Microstructure Evolution of Titanium Alloy Pipe during Flattening Processing

TA24 titanium alloy pipe with 638mm diameter and 19mm wall thickness is carried out continuous load flatten test, and the stress of internal and external pipe wall during flatten process is studied in this paper. The results show that the TA24 titanium alloy tube has good flattening performance, and the flattening process has experienced original stage, flattened oblate stage, flattened straight wall stage, flattened depressed stage, flattened concave contact stage. During the flattening process, the outer layer of the upper and lower wall of the tube is subjected to compressive stress, and the inner layer material is subjected to tensile stress. The tensile and compressive forces cause the vertical part of the upper and lower walls to be concave. The outer layer of the left and right circular arc parts is subjected to tensile stress and the inner layer is subjected to tensile stress. The compressive stress also causes the radius of the arc to decrease due to the combined force of the tensile and compressive forces, that is, the flattening occurs. With the decrease of and pressing distance under continuous loading condition, the metal on the left and right sides of the pipe gathers toward the middle depression, which aggravates the deformation of the upper and lower walls until the upper and lower walls contact, and the arc radius of the left and right walls decreases until the outer surface cracks. The pipe microstructure changes significantly into elongated deformation structure during the flattening process. The most severe part of the deformation is the left and right end arc of the pipe, followed by the upper and lower end depression.