Titanium Alloy Plates Research Articles

Study of coatings of the Ni–Ti–(SiC, WC, B4C) system applied to the surface of titanium alloy plates using cold gas dynamic spraying and laser processing

The technology of applying composite intermetallic coatings of the Ni–Ti system reinforced with carbides based on powders (SiC, WC, B4C) on the surface of titanium alloy plates with the sequential use of the CGDN method and laser processing is considered. The technological parameters of the laser-thermal processing, ensuring the production of composite coatings of the Ni–Ti–(SiC, WC, B4C) system of high hardness, are determined.

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.

Finite element analysis of anatomic plate fixation for proximal clavicular fractures

To explore establishment and finite element analysis of personalized proximal clavicular anatomical plate screw fixation model. A 40-year-old male healthy volunteer was selected and the finite element analysis modules of 3D reconstruction software Mimics 15.01, Hypermesh 2019 and Abaqus 2020 were used. The finite element model of anatomic plate at the proximal clavicle was established, and a vertical load of 250 N was applied to the distal end of long axis of clavicle about 15 mm, then the overall structure, plate and screw displacement cloud image, Mises stress distribution were observed. The displacement distribution of the overall structure shows the maximum displacement was distributed on the distal clavicle. Under the four conditions of normal upper limb weight, longitudinal clavicle fracture, oblique fracture and shoulder impact violence during fall, longitudinal clavicle fracture and oblique fracture, the maximum displacement were 1.04 mm, 1.03 mm, 1.35 mm and 1.33 mm, respectively. The displacement cloud map of titanium alloy steel plate showed the largest displacement was distributed near the distal clavicular bone, and the maximum displacement were 0.89 mm, 0.88 mm, 1.10 mm and 1.09 mm, respectively. The displacement cloud map of titanium alloy screw showed the largest displacement was distributed at the root of the distal screw, and the maximum displacement were 0.88 mm, 0.87 mm, 1.08 mm and 1.06 mm, respectively. Mises stress distribution showed the maximum stress was mainly distributed on titanium alloy plates and screws, and the stress on the clavicle was very small. Mises stress distribution cloud showed the maximum Mises stress was distributed at the second row of screw holes near the clavicle, and the maximum Mises stress were 673.1, 678.1, 648.5, 654.4 MPa, respectively. The maximum stresses of titanium alloy screws were 414.5, 417.4, 415.8 and 419.7 MPa, respectively. The biomechanical changes of personalized proximal clavicular anatomical plates are demonstrated by using 3D finite element method to provide biomechanical data for personalized proximal clavicular anatomical plates.

Effect of Ta/Ni dual-interlayer on the microstructure and properties of high strength titanium alloy and steel composite plate

The combination of ultra-high-strength Ti-6Al-4V (TC4) titanium alloy and 30CrNiMoNb (6211) steel was achieved by adding Ta/Ni dual-interlayer and rolling at 950 °C through welding a symmetrical blank sleeve with a vacuum electron beam. In order to unveil the metallurgical bonding mechanism and the interfacial structure, SEM, XRD, and compression-shear performance tests were used. The results revealed the presence of thin-film brittle TiC, TiFe, and TiFe2 compounds at the TC4/6211 interface, resulting in an increased risk of interface mismatch and brittle fracture along the matrix phase interface, and the average interfacial bonding strength was tested at 323 MPa.In contrast, the TC4-Ta interface and the 6211-Ni interface in the TC4/Ta/Ni/6211 composite plate displayed good solid solution formation. The strengthening mechanism of the Ta/Ni dual-interlayer interfacial bonding was analyzed using selected area electron diffraction (SAED), revealing that the Ta-Ni diffusion region consisted of Ni3Ta and Ni2Ta. The addition of the Ta/Ni dual-interlayer prevented the aggregation of Ti and Fe atoms to form Ti-Fe compounds. The malleable intermetallic compounds of Ni3Ta and Ni2Ta effectively coordinated deformation, leading to an average interfacial bonding strength of 469 MPa, which was 45.2 % higher than the composite plate without Ta/Ni dual-interlayer.

Anisotropy in Chip Formation in Orthogonal Cutting of Rolled Ti-6Al-4V

Abstract The increasing demand for titanium alloys in aerospace and medical device industries stems from their lightweight and high strength properties. Enhancing machining technologies for titanium alloys is critical for reducing production time and costs. This study investigates the anisotropy in machining of rolled titanium alloy plates with orthogonal cutting tests. The mechanical properties of these plates exhibit anisotropy due to the rolled texture of hexagonal close-packed (HCP) structure. Observations of chip morphologies and cutting forces are conducted with changing cutting direction angles relative to the rolling direction. The result shows that the chip morphology is influenced by the cutting direction angle. When cutting parallel to the rolling direction with an orthogonal cutting tool with 30° rake angle, serration free chips are produced, while perpendicular cutting results in serrated chips. The chip thickness, the serration pitch, and the serration length vary with the cutting direction angle. The serration length is associated with an anisotropic deformation index, which characterizes anisotropic behavior in chip formation. Lower index values suppress the formation of undesirable serrated chips.

Microstructure and mechanical characterization of weldments of titanium alloy plates joined using different welding techniques

Microstructure and mechanical characterization of weldments of titanium alloy plates joined using different welding techniques

Synthesis and characterization of Fe3O4@SiO2 core-shell nanoparticles for mirror and efficient magnetic compound fluid polishing of TC4 titanium alloy

To fully investigate the polishing performance of the Fe3O4@SiO2 core–shell abrasive for TC4 titanium alloy plate and solve the problem of uneven distribution of abrasive particles in magnetic compound fluid polishing (MCFP) and obtain ultra-smooth titanium alloy surface. In this paper, the functional Fe3O4@SiO2 core–shell abrasives were prepared and characterized by XRD, FTIR, VSM and TEM to demonstrate the successful encapsulation of SiO2 in Fe3O4 first. Second, a new polishing device was built to perform polishing experiments. Four different fractions of Magnetic compound fluid (MCF) were configured and utilized in polishing experiments for MCFP of TC4 titanium alloy to verify the polishing properties. Finally, the contact model between abrasive particles and workpiece is established and the material removal mechanism is discussed. The results show that SiO2 was successfully coated on Fe3O4. The polishing results show that the MCF containing the core–shell structure had the best polishing effect. The surface roughness Ra decreased from 0.201 μm to 0.025 μm after 20 min of polishing. The surface roughness of TC4 titanium alloy with an initial roughness Sa of 0.248 μm is reduced to 0.023 μm after polishing by Fe3O4@SiO2 core–shell abrasive. It is shown that the application of core–shell abrasive to process titanium alloys can obtain smooth and defect-free surfaces with good polishing performance. The surface quality of titanium alloy can be improved effectively by using core–shell abrasive, and a new idea for polishing titanium alloy is proposed. This study plays an important role in solving the problem of uneven particle distribution in MCFP. These results pave the way for further research into the application of core–shell abrasives in precision machining and expand the application scope of particles with core–shell structure.

Study on crack initiation mechanism of notched TC4 titanium alloy plate based on acoustic emission information entropy

ABSTRACT Titanium alloys are widely used in high-end manufacturing fields such as aerospace and nuclear energy due to their excellent mechanical properties and corrosion resistance, but it is prone to cracking under load, seriously affecting its performance and safety. Therefore, studying the crack initiation process of titanium alloys is of great significance for improving their service life and safety. In this study, TC4 titanium alloy material is taken as the research object, and the crack emergence mechanism during its tensile fracture process is investigated by combining tensile test and AE test. The experiments were carried out under displacement-controlled conditions, and crack emergence detection was carried out by two methods: AE characterisation parameters and AE information entropy, and SEM was used to observe and analyse the specimen fracture. The results indicate that the AE characteristic parameters of different notched specimens have the same evolution pattern, and this method can be used to predict crack initiation, but there is a certain degree of uncertainty. Compared with the former, the information entropy theory can more accurately predict crack initiation. Therefore, the analysis of the entropy of AE information can be used as a highly practical real-time condition detection method to provide effective detection means for engineering applications.

Microstructure and mechanical properties in electron beam scanning welded joints of super thick titanium alloy plates

It is generally difficult to obtain good weld formation and excellent properties in super thick titanium alloy joints via conventional electron beam welding (EBW) methods due to the fact that the melt pool flow becomes more unstable as the plate thickness increases. In this study, electron beam scanning welding (EBSW) was utilized to weld 100 mm Ti–6Al–3Nb–3Zr–1Mo titanium alloy plates to improve the weld formation and impact toughness through the scanning effect. The results revealed that there were spatter and cutting defects on the surface and inner pore defect in the normal EBW joint, which could be effectively eliminated via EBSW. The decrease of the amplitude of the fluid flow rate and the change of the velocity direction were mainly responsible for this. A large amount of lamellar α phase with similar orientation was formed in the fusion zone (FZ) due to the fast cooling rate. The joint coefficient for both EBSW and EBW reached 100%, with the joint tensile strength of ∼840 MPa. The impact energy of the FZ in the EBSW joint was 70.5 J, reaching 210.4% of that of the BM (33.5 J). The impact toughness increase ratio in this study was far larger than those for Ti alloy welds ever reported, which was mainly attributed to that the high angle α colony boundaries with high preferred orientation in the FZ deflected the crack propagation direction. This study provides a reference for the strength-toughness design of EBWed joints of super thick Ti6331 titanium alloy.

A Super-Adhesive 2D Diamond Smart Nanofluid with Self-Healing Properties and Multifunctional Applications.

Smart responsive materials are capable of responding to external stimuli and, compared to traditional materials, can be effectively reused and reduce usage costs in applications. However, smart responsive materials often face challenges such as the inability to repair extensive damage, instability in long-term performance, and inapplicability in extreme environments. This study combines 2D diamond nanosheets with organic fluorinated molecules to prepare a smart nanofluid (fluorinated diamond nanosheets, F-DN) with self-healing and self-adhesion properties. This smart nanofluid can be used to design various coatings for different applications. For example, coatings prepared on textured steel plates using the drop-casting method have excellent superhydrophobic and high oleophobic properties; coatings on titanium alloy plates achieve low friction and wear in the presence of lubricating additives of F-DN in perfluoropolyether (PFPE). Most impressively, coatings on steel plates not only provide effective corrosion resistance but also have the ability to self-heal significant damage (approximately 2 mm in width), withstand extremely low temperatures (-64 °C), and resist long-term corrosion factors (immersion in 3.5 wt % NaCl solution for 35 days). Additionally, it can act as a "coating glue" to repair extensive damage to other corrosion-resistant organic coatings and recover their original protective properties. Therefore, the smart nanofluid developed in this study offers diverse applications and presents new materials system for the future development of smart responsive materials.

A biomechanical study of a polymer material bundled rib fracture fixator.

Rib fractures are one of the most common blunt injuries, accounting for approximately 10% of all trauma patients and 60% of thoracic injuries. Multiple rib fractures, especially flail chest, can cause local chest wall softening due to the loss of rib support, leading to paradoxical breathing, severe pain, and a high likelihood of accompanying lung contusions. This study investigates the mechanical properties of a new polymer material rib internal fixator to provide theoretical data for its clinical use. We conducted in vitro mechanical tests on 20 fresh caudal fin sheep ribs, using different fracture models across four randomly assigned groups (five ribs per group). The fixators were assessed using non-destructive three-point bending, torsion, and unilateral compression tests, with results averaged. Additionally, finite element analysis compared stress and strain in the polymer fixators and titanium alloy rib plates during bending and torsion tests. In vitro tests showed that the polymer fixators handled loads effectively up to a maximum without increase beyond a certain displacement. Bending and torsion tests via finite element analysis showed the polymer material sustained lower maximum equivalent stresses (84.455MPa and 14.426MPa) compared to titanium alloy plates (219.88MPa and 46.47MPa). The polymer rib fixator demonstrated sufficient strength for rib fracture fixation and was superior in stress management compared to titanium alloy plates in both bending and torsion tests, supporting its potential clinical application.

Three-Dimensional-Printed Modular Titanium Alloy Plates for Osteosynthesis of the Jawbone.

The titanium-aluminum-vanadium alloy (Ti-6Al-4V) is frequently used in implantology due to its biocompatibility. The use of 3D printing enables the mechanical modification of implant structures and the adaptation of their shape to the specific needs of individual patients. The titanium alloy plates were designed using the 3D CAD method and printed using a 3D SLM printer. Qualitative tests were performed on the material surface using a microcomputed tomography scanner. The cytotoxicity of the modular titanium plates was investigated using the MTT assay on the L929 cell line and in direct contact with Balb/3T3 cells. Cell adhesion to the material surface was evaluated with hFOB1.19 human osteoblasts. Microbial biofilm formation was investigated on strains of Lactobacillus rhamnosus, Staphylococcus epidermidis, Streptococcus mutans and Candida albicans using the TTC test and scanning electron microscopy (SEM). The surface analysis showed the hydrophobic nature of the implant. The study showed that the titanium plates had no cytotoxic properties. In addition, the material surface showed favorable properties for osteoblast adhesion. Among the microorganisms tested, the strains of S. mutans and S. epidermidis showed the highest adhesion capacity to the plate surface, while the fungus C. albicans showed the lowest adhesion capacity. The manufactured modular plates have properties that are advantageous for the implantation and reduction in selected forms of microbial biofilm. Three-dimensional-printed modular titanium plates were investigated in this study and revealed the potential clinical application of this type of materials, regarding lack of cytotoxicity, high adhesion properties for osteoblasts and reduction in biofilm formation. The 3D CAD method allows us to personalise the shape of implants for individual patients.

Structural design and evaluation of bone remodeling effect of fracture internal fixation implants with time-varying stiffness

The stiffness of an ideal fracture internal fixation implant should have a time-varying performance, so that the fracture can generate reasonable mechanical stimulation at different healing stages, and biodegradable materials meet this performance. A topology optimization design method for composite structures of fracture internal fixation implants with time-varying stiffness is proposed, considering the time-dependent degradation process of materials. Using relative density and degradation residual rate to describe the distribution and degradation state of two materials with different degradation rates and elastic modulus, a coupled mathematical model of degradation simulation mechanical analysis was established. Biomaterial composite structures were designed based on variable density method to exhibit time-varying stiffness characteristics. Taking the bone plate used for the treatment of tibial fractures as an example, a composite structure bone plate with time-varying stiffness characteristics was designed using the proposed method. The optimization results showed that material 1 with high stiffness formed a columnar support structure, while material 2 with low stiffness was distributed at the degradation boundary and inside. Using a bone remodeling simulation model, the optimized bone plates were evaluated. After 11 months of remodeling, the average elastic modulus of callus using degradable time-varying stiffness plates, titanium alloy plates, and stainless steel plates were 8 634 MPa, 8 521 MPa, and 8 412 MPa, respectively, indicating that the use of degradable time-varying stiffness plates would result in better remodeling effects on the callus.

Microstructural examination and ballistic testing of field-assisted sintering technology produced Ti-TiB2 functionally graded material composite armour plates

High hardness ceramics are potent in their use for armour applications globally, but intrinsically brittle. This can result in fragmentation damage, as well as low multi hit capacity. In this work, alternative 250 mm diameter Ti-6Al-4 V discs were produced using field-assisted sintering technology (FAST) with and without stepped functional grading using low wt.% TiB2 concentrations, respectively, to investigate their microstructure and ballistic performance. The in situ generation of a significant quantity of high strength, ceramic TiB needles was confirmed for the samples, and the plates were ballistically tested to attain V50 values. In addition to a microstructural examination. The ballistic results indicated a superior behavior to the monolithic titanium alloy plates without TiB2 additions.

Ductile Fracture of Titanium Alloys in the Dynamic Punch Test

Estimates of physical and mechanical characteristics of materials at high strain rates play a key role in enhancing the accuracy of prediction of the stress–strain state of structures operating in extreme conditions. This article presents the results of a combined experimental–numerical study on the mechanical response of a thin-sheet rolled Ti-5Al-2.5Sn alloy to dynamic penetration. A specimen of a titanium alloy plate underwent punching with a hemispherical indenter at loading rates of 10, 5, 1, and 0.5 m/s. The evolution of the rear surface of specimens and crack configuration during deformation were observed by means of high-speed photography. Numerical simulations were performed to evaluate stress distribution in a titanium plate under specified loading conditions. To describe the constitutive behavior and fracture of the Ti-5Al-2.5Sn alloy at moderate strain rates, a physical-based viscoplastic material model and damage nucleation and growth relations were adopted in the computational model. The results of simulations confirm a biaxial stress state in the center of specimens prior to fracture initiation. The crack shapes and plate deflections obtained in the calculations are similar to those observed in experiments during dynamic punching.

Multi-pass butt welding of thick TA5 titanium-alloy plates by MIG: Microstructure and properties

A 35 mm-thick TA5 titanium alloy plate was successfully joined by metal inert-gas (MIG) welding. The welded joints were analyzed in a more integrated and comprehensive manner. The joint microstructure was analyzed by OM, SEM, EBSD, and TEM. Mechanical properties were analyzed by tensile, impact, and microhardness tests. The corrosion resistance of the joints was determined by FeCl3 immersion corrosion. Experimental results showed that the mechanical properties and corrosion resistance of the fusion zone (FZ) were poorer than those of the base material (BM). The mechanical properties of the welded joints were related to the acicular grains in the FZ. The 260 A joints showed relatively good mechanical properties. With increased welding current, the proportion and size of the acicular grains increased, and the strength of the joint increased, but the plastic toughness decreased. When the welding current was too small, anisotropy occurred in the FZmiddle, which affected the mechanical properties of the joints. The corrosion resistance of the FZ was lower than that of the BM, and the corrosion resistance of the three groups of joints decreased in the order 300 A > 230 A > 260 A.The welding current affected the corrosion resistance of the FZ by influencing the grain size of the FZ, the frequency of the HAGBs, and the GND density.

Development of a highly sensitive non-enzymatic electrochemical cholesterol biosensor based on Ag with Cu2O nanomaterial deposited on TiO2 nanotubes

We developed a highly sensitive non-enzymatic biosensor based on hybrid Ag-Cu2O@TNTs nanostructure aggregate for the detection of cholesterol. A facile anodization process on a thin titanium alloy (Ti6Al4V) plate was achieved to deposit TiO2 nanotubes (TNTs). Subsequently, TNTs was decorated with Cu2O nanomaterials (NM) using wet chemical bath deposition (CBD) technique. The electro-deposition of silver (Ag) nanoparticles on Cu2O@TNTs hybrid aggregate produced high electroactive surface area which enhanced the electron transfer rate. The structure of Ag-Cu2O@TNTs was examined using X-ray diffraction (XRD), transmission emission microscopy (TEM), and field emission scanning electron microscopy (FE-SEM). Cyclic voltammetry (CV) and amperometry techniques were utilized to study the electrochemical behaviour of nanostructures. The hybrid nanostructure demonstrated great sensitivity (12140.06 μAmM−1cm−2) compared to pure TNTs and Cu2O@TNTs with low detection limit (0.057 mM) and fast response. This study highlights exciting potential of nanocomposites in advancement of reproducible and selective biosensor applications.

Transonic leading-edge stall flutter: modelling, simulations and experiments

This work is a numerical and experimental study of a rectangular thin plate undergoing stall flutter at Mach 0.8. This constitutes one of the first studies of this kind where three-dimensionality is fully implemented in a numerical simulation including the test-section effects characterizing wind-tunnel experiments. In order to break down the fluid–structure interaction to its main driving phenomena, an aerodynamic model is proposed that is based on computationally inexpensive steady-state simulations. Two types of dynamic instability are observed in the numerical simulations; Flutter by mode coalescence is promoted at zero flow incidence, however, high bending precludes this from happening for higher values of angle of attack. Stall flutter is instead a nonlinear one-degree type of instability. Both of these instability mechanisms can be explained in terms of hysteretic behaviour of the pressure distribution, which becomes more pronounced at high angles of attack, when a large separation region is formed. Tests were conducted employing titanium alloy plates in order to survive the aerodynamic loads characterizing the wind-tunnel initial transient. However, due to wall interference, high bending was promoted so that the internal stress exceeded the yield values before flutter could be measured. Numerical simulations were in general agreement with the experiment in terms of both amplitude and oscillation frequency.

Microstructure and residual stress distribution of electron beam-welded joints of a 50 mm-thick TA15 titanium alloy plate

Abstract Vacuum electron beam welding was applied to a 50 mm-thick TA15 titanium alloy plate. Microstructure observation and microhardness testing were performed. Meanwhile, the residual stress on the surface at different distances from the weld centre was measured via the hole drilling method. A finite element model for electron beam welding of the TA15 titanium alloy plate was constructed on commercial finite element software. Experimental results showed that the microstructure of the weld zone consisted of a basket martensitic phase. The highest microhardness in the weld zone was 409 HV, and the microhardness of the base metal was the lowest. The maximum gradient change area was located at the HAZ near the base metal. The peak value of longitudinal residual stress from the simulation was 880 MPa, which was in the weld metal. The sharp change area of longitudinal residual stress gradient was located in the base metal near HAZ.

Research on Alternating Current Field Measurement Method for Buried Defects of Titanium Alloy Aircraft Skin.

Titanium alloys are extensively used in the manufacturing of key components in aerospace engines and aircraft structures due to their excellent properties. However, aircraft skins in harsh operating environments are subjected to long-term corrosion and pressure concentrations, which can lead to the formation of cracks and other defects. In this paper, a detection probe is designed based on the principle of alternating current field measurement, which can effectively detect both surface and buried defects in thin-walled titanium alloy plates. A finite element simulation model of alternating current field measurement detection for buried defects in thin-walled TC4 titanium alloy plates is established using COMSOL 5.6 software. The influence of defect length, depth, and excitation frequency on the characteristic signals is investigated, and the detection probe is optimized. Simulation and experimental results demonstrate that the proposed detection probe exhibits high detection sensitivity to varying lengths and depths of buried defects, and can detect small cracks with a length of 3 mm and a burial depth of 2 mm, as well as deep defects with a length of 10 mm and a burial depth of 4 mm. The feasibility of this probe for detecting buried defects in titanium alloy aircraft skin is confirmed.