Machining Titanium Research Articles

Recent Contributions to the Development of Barrel End-Mill Machining Technologies for Titanium Alloys in the Aerospace Context

This study investigates the utilization of barrel end-mills in machining titanium alloys for aerospace applications. It involves a comprehensive review of the relevant literature and a preliminary experimental investigation, incorporating the influence of measurement direction on surface roughness and the behavior of cutting forces. The primary objective is to assess the performance and efficiency of these end-mills when machining challenging materials and to identify optimal cutting strategies. This paper emphasizes the significance of titanium alloys in the aerospace sector, due to their exceptional mechanical properties, and the problems encountered in their processing. It also highlights the advantages of barrel end-mills, such as enhanced accessibility and superior surface finish. Through a combination of literature review, practical experimentation under controlled conditions, and statistical analysis, this study investigates the surface roughness of the Ti-6Al-4V titanium alloy, confirming a significant difference between longitudinal and transverse roughness. The preliminary experiment revealed that the average values of longitudinal and transverse roughness were 0.237 µm and 0.263 µm, respectively. The coefficients of variation indicated a greater variation in longitudinal roughness (19.79%) compared to transverse roughness (18.61%). This study’s conclusions provide a solid foundation for future research into machining titanium alloys with barrel end-mills, contributing to the optimization of manufacturing processes and the enhancement of aerospace component performance.

Tribological Analysis of Laser-Textured WC-Co Against Ti6Al4V Under Dry and Lubricated Conditions for Different Sliding Times

Machining titanium alloys, particularly Ti6Al4V, pose significant challenges in manufacturing engineering. The combination of high strength and low thermal conductivity makes Ti6Al4V a particularly difficult material to machine. One of these difficulties is the rapid wear and short tool life of cutting tools, which substantially increases manufacturing costs. To address this issue, the texturing of cutting tools, especially using laser-based techniques, has garnered significant attention due to its potential to enhance the tribological performance of textured surfaces. In this paper, by means of a groove design applied to a tungsten carbide (WC) disc by laser surface texturing (LST), its behavior and wear have been evaluated after subjecting it to tribological pin-on-flat tests by confronting it with Ti6Al4V pins with different reciprocating times (250 s, 500 s, 750 s and 1000 s) in lubricated and dry conditions. In addition, these same tests have been replicated without textures for comparison. Through conducting this research, we expect to gain new insights into texturing processes and their influence on friction and sliding behavior under lubricated conditions. Additionally, the study aims to evaluate how lubricant retention capacity varies to reduce friction and wear across different testing durations. The results show better behavior with textures, reaching a higher rate of volume loss in the titanium pins. The main conclusions obtained after these tests are that textures offer a better performance in tests up to 800 s. In addition, after this time, the lubricant begins to lose its properties, becoming an abrasive paste.

Identification of parameter-dependent machine learning models for tool flank wear prediction in dry titanium machining

This study uses machine learning (ML) techniques to predict maximum flank wear on cutting tools during the turning of Ti6Al4V, a titanium alloy known for its challenging machinability. We used three models (a) support vector machines (SVM), (b) random forests (RF), and (c) neural networks (NN) to predict maximum flank wear. The machining parameters are taken as input data sets, which compromise cutting speed, feed, and machining time. All the experiments are done at a constant depth of cut to predict maximum flank wear as an output variable. The forecasted maximum flank wear was validated using experimental data to verify their precision. The SVM model outperformed the other ML models in a wider range of cutting parameters concerning tool flank wear. The SVR model is the most accurate model with an average forecasting error of 3.24%. In forecasting maximum flank wear, the RF and NN models followed, with average forecasting errors of 3.88% and 3.71%, respectively. Additionally, the SVM model's robustness was further validated by its ability to maintain stability at varying cutting speeds and feed rates. The research enhances the economics of the machining process by predicting tool flank wear and fostering sustainability in the manufacturing industry, thereby demonstrating the applicability of ML techniques.

Large strain extrusion machining of pure titanium at cryogenic temperature: experimental and simulation insights into microstructure and mechanical properties evolution

Large strain extrusion machining of pure titanium at cryogenic temperature: experimental and simulation insights into microstructure and mechanical properties evolution

A review of the use of cryogenic coolant during machining titanium alloys

Titanium alloys are considered difficult-to-machine materials, and much effort has been made to improve their machinability through various approaches. The use of cryogenic coolants during machining, sometimes referred to as cryogenic machining, is a popular environmentally friendly technique that promises to reduce cutting zone temperatures, reduce friction, and enhance tool life during machining operations. This review article explores the use of cryogenic coolants during titanium machining and presents an overview of research progress and knowledge gaps. The various coolants and methods for cryogenic machining are reviewed, along with the effectiveness of these methods in terms of key machinability criteria, including tool wear, tribological properties, and heat transfer. Issues in sustainability are also explored.

Development of Highly Machinable Ti Alloy with Exceptional Tensile Properties by Er Alloying Element Addition

This study demonstrates that the addition of the rare earth element Erbium (Er) significantly enhances the machinability and tensile properties of titanium (Ti). Pure Ti alloys and Er-added Ti alloys with 0.5-1.1 wt.% Er content were prepared, and their microstructure, machinability, and tensile properties were compared. Two different types of Er secondary phase particles were identified in the microstructure: pure Er and Er-oxide. The amounts of these particles increased with higher Er content. The machinability of the Eradded Ti alloys was significantly improved due to the ability of Er secondary particles to cut machining chips or absorb heat from localized deformation within the Ti matrix. In addition, Er-added Ti alloys exhibited higher strength than pure Ti. The strength enhancement was attributed to grain refinement induced by the Er element. Er secondary phase particles reduced the β grain size during solidification, and they also served as preferential sites for α nucleation during the β → α phase transformation, resulting in a refined microstructure. In addition, the Er secondary phase contributed to the strength enhancement through the well-known precipitation strengthening mechanism. Although ductility decreased with higher Er content due to the increased amount of Er secondary phase particles, 0.5 wt.% Er-added Ti showed no such degradation; its ductility was comparable to that of pure Ti. Er-oxidation was expected to reduce oxygen content within the Ti matrix, enhancing intrinsic Ti ductility; this effect offset the adverse impact on ductility caused by the Er secondary phase particles. Above 0.5 wt.% Er, the adverse effects caused by the Er secondary phase particles overwhelmed the beneficial effect caused by the reduction in oxygen content. The present findings will contribute significantly to the development of highly machinable Ti alloys with superior tensile properties.

Efficacy of 3D Printed Finger Prosthesis for patients affected with Hansen’s Disease to Restore Hand Function

Introduction The greek word LEPROSY was renamed by the term Hansen’s disease by Norwegian physician Gerhard Armauer Hansen. In 2009, WHO Goodwill Ambassador Yohei Sasakawa called for an end to usage of the word leprosy, since he described it as ‘an extremely damaging term’ that contributes to stigma and impacts human rights. Since 2010, leprosy mission gives assurance that the word is not condoned by media channels or used by public figures. HD ranges from mild to severe (based on one or more skin areas affected and damage caused to organs).There were 5.2 million people affected by leprosy globally, in 1980 but by 2020 this decreased to fewer than 2,00,000. Leprosy can affect people in many ways. The Cochrane database of systemic reviews , 2019 lists that 30% of people affected with leprosy experience nerve damage. People with untreated leprosy become visibly disfigured often have psychologic and social problems. Mosby’s Medical Dictionary 2009 defines trophic ulcers as “a pressure ulcer caused by external trauma to a part of body or by vascular insufficiency leading to loss of afferent nerve fibres. The most severe complications result from infection of the peripheral nerves, which causes deterioration of sense of touch and inability to feel pain and temperature. The nerve damage is reversible when treated early, but becomes permanent when appropriate treatment is not available for sufferer. Damage to nerves may cause loss of muscle function, leading to paralysis. It may also lead to sensation abnormalities or numbness, which may lead to additional infections, ulcerations, and joint deformities. Also, damage to peripheral nerves may cause muscle weakness that can result in deformities. M. leprae attacks nerve endings and destroys the body's ability to feel pain and injury. Without feeling pain, people with leprosy have an increased risk of injuring themselves. In some cases, autoamputation has been reported to affect the tip of fingers. People with peripheral nerve damage may unknowingly burn, cut, or otherwise harm themselves. Infected nerves may enlarge also & this can be palpated. The fingers may be weakened, causing them to curve inward (claw hand). When therapeutic amputation is decided for a patient affected with HD, occupational therapist can suggest preserving as much of hand as possible, to prepare wearing 3D printed prosthesis. 3-D printing is a new rising technology, Objects made in 3D printing range from plastic figurines and mould patterns to steel machine parts and titanium surgical implants. Related to Hansen Disease, It facilitates manufacturing hand parts with irregular and uncommon geometric shapes. Freedom offered by 3D printing techniques has paved the way for the application of new design for best appearances. The advantages of 3D printing could be used to fabricate prosthetic hands based on the biological design principles. The purpose of this study is to assess efficacy of 3-D printed finger prosthesis to manipulate objects & to restore hand function in HD clients.

Investigation of the Effects of Cutting Fluid Application with Minimum Quantity Lubrication (MQL) Method on the Machinability of Pure Titanium

Machining is one of the widely used methods in today's technology and there are many parameters that affect the machinability of the produced product. In the machining process, the machinability of the product depends on parameters such as feed rate, depth of cut, cutting speed and cutting fluid. The use of cutting fluid during the process has advantages such as improving surface quality, but also disadvantages such as increased cost and environmental damage. Due to these disadvantages of cutting fluid in manufacturing processes, alternative methods have been developed. The method called minimum quantity lubrication (MQL) not only reduces cost but also improves machinability. In this study, the machinability of titanium turning was evaluated with main cutting force, surface roughness and temperature measured in the primary cutting zone data. MQL method was used in the study and Taguchi L9 model was applied. The results were compared between dry cutting and MQL atmospheres. The reliability of the data and the degree of influence of the parameters were analyzed by ANOVA. In this study, the shear force data obtained in the dry shear atmosphere were higher than the data obtained in the MQL method. In addition, the surface roughness values obtained in dry cutting atmosphere were also relatively high. The optimum cutting speed, feed rate and depth of cut values for the process were determined as 60 m/min, 0.05 mm/rev and 0.5 mm, respectively.

Optimization and experimental study on cathode structure of electrochemical machining titanium alloy inner helix

Optimization and experimental study on cathode structure of electrochemical machining titanium alloy inner helix

Investigation on the impact of sub-zero treated electrodes in EDM

ABSTRACT Owing to the challenges faced during conventional machining of Titanium (Ti) alloys due to their low thermal conductivity and high chemical reaction, non-conventional machining techniques are used. Electrical Discharge Machining (EDM) is a promising solution that can precisely machine hard materials into intricate geometries but faces lower material removal rate, higher tool wear rate, and poor surface quality. In this research work, the effect of sub-zero treatments on EDM electrodes was investigated, and experimental investigations were conducted to identify the impact of sub-zero treated electrodes during EDM of Ti-6Al-4V under different discharge energy regimes. Peak Current, Pulse-On-Time and Gap Voltage were varied in 3 levels to evaluate the effect on MRR and TWR. A comprehensive study on EDMed surfaces has been assessed using the morphological and metallurgical observations from SEM micrographs, EDAX and XRD patterns. Sub-zero treated electrodes outperformed the Untreated (UT) electrodes regarding erosion rates and surface quality.

Design and Evaluation of an Eco-Efficient RHVT-Cooled Ti6Al4V Drilling Process

The continuous demand focused on optimizing titanium machining techniques in the aerospace industry, makes improving machining processes in this area of great interest to the industry. The contamination produced by the coolants used to machine titanium is a major problem to be addressed, since it is a material that requires cooling due to its strength, physical qualities and low thermal conductivity. That is why the implementation of a RHVT cooling system can improve the current situation. The aim of this work is to compare the final quality of the drilling by applying the system of RHTV (Ranque Hilsch Vortex Tube) cooling techniques and to see the advantages of its application with the dry machining process. This cooling system is expected to reduce drilling temperatures, thereby increasing the environmental performance of the manufacturing process. It is expected to set up a preliminary study based on a comparison between dry drilling and drilling assisted by the application of RHTV. Macro and microgeometric defects will be evaluated to determine the cooling system efficiency, as well as the machining temperatures reached.

A review on Wire-EDM of bio titanium

Nonconventional machining technologies have been found viable to manufacture various products from a wide range of engineering materials. Wire electric discharge machining (WEDM), also known as Wire-EDM, is one of the important thermal type nonconventional machining technologies. Wire-EDM is being preferably used by manufacturers to produce biomedical devices including bio and dental implants. This paper presents an overview of capabilities of wire-EDM type nonconventional machining technology for the precise machining of titanium and its alloys for biomedical applications. It reviews the important research work conducted on machining titanium alloys by wire electrical discharge machining (WEDM). Their findings and achievements are discussed to encourage further research and development in the biomaterial machining area.

Optimization Milling Force and Surface Roughness of Ti-6Al-4V Based on Ultrasonic-Assisted Milling (UAM): An Experimental Study.

This study aimed to develop a longitudinal ultrasonic-assisted milling system to investigate the machinability of titanium (Ti) Alloy Ti-6Al-4V (TC4). Aiming at reduced milling force and enhanced surface quality, ultrasonic-assisted milling was investigated taking into account the following processing parameters: spindle speed (cutting rate) n, feed per tooth fz, milling depth ap, and ultrasonic amplitude A. A comparison was made with conventional milling. The results of univariate tests demonstrated that the ultrasonic amplitude had the most significant impact on the milling force along the z-axis, resulting in a reduction of 15.48% compared with conventional milling. The range analysis results of multivariate tests demonstrated that ap and fz were the dominant factors influencing the cutting force. The minimum reduction in the milling force in ultrasonic-assisted milling along the x-, y-, and z-axes was 11.77%, 15.52%, and 17.66%, respectively, compared with that in conventional milling. The ultrasonic-assisted milling led to reduced surface roughness and enhanced surface quality; the maximum surface roughness in ultrasonic-assisted milling was 25.93%, 36.36% and 26.32% in terms of n, fz, and ap, respectively. In longitudinal ultrasonic-assisted milling, the periodic "separation-contact" was accompanied by microimpacts, resulting in even smaller intermittent periodic cutting forces. Hence, regular fish scale machining mesh was observed on the processed surface, and the workpiece surface exhibited high cleanness and smoothness. The reasonable configuration of ultrasonic-assisted milling parameters can effectively improve the milling force and surface quality of Ti alloys and accumulate reference data for the subsequent machining process research.

Comparative analysis of the cutting performances of SiAlON ceramic, cubic boron nitride and carbide cutting tools for titanium machining

The efficiency of machining operation is partly a function of the cutting parameters, such as the cutting speed, depth of cut and cutting feed rate. With an effective cutting performance of any cutting tool, manufacturing industries will remain competitive and hence strive to meet the dynamic service and functional requirements expected of the material. Hence, the purpose of this research is to experimentally perform a comparative analysis of the cutting performances of SiAlON, a ceramic alloy consisting of the elements: silicon, aluminium, oxygen and nitrogen; cubic boron nitride (CBN) and carbide cutting tools, during a titanium machining process. A face milling operation was performed on a computer numerical control (CNC) milling machine from these three different types of cutting tools, for the determination of the cutting forces, cutting temperatures, cutting vibrations produced and the surface roughness, achieved during the machining of titanium (Ti-6Aℓ-4 V) alloy. The response surface methodology was adopted for the possible combination of the cutting parameters for the determination of the practical experimental results of the cutting responses.

Development and Experimental Study of Electrochemical Diamond Drilling Process on Ti6Al4V

Electrochemical diamond drilling (ECDD) process is a chemical energy-based hybrid machining technique where the removal of material from the workpiece occurs with the help of both anodic dissolution and mechanical abrasion. Titanium alloys have remarkable mechanical as well as chemical properties, however, excellent properties enhance the difficulty in machining of titanium. Ti6Al4V, alloy of titanium contains [Formula: see text] and [Formula: see text] phase which have different dissolution potentials and produces poor surface when electrochemically machined. Here electrochemical diamond drilling of Ti6Al4V is done with a diamond abrasive tool which helps in mechanical abrasion and further by electrochemical dissolution hence this increases the rate of material removal and minimizes surface roughness. From the experiments, the suitable machining range was found to be, voltage 13–17[Formula: see text]V, tool feed rate 0.09–0.15[Formula: see text]mm/min, and electrolyte concentration of electrolyte from 225[Formula: see text]g/l to– 275[Formula: see text]g/l, with tool rotation ranging between 800[Formula: see text]RPM and 1200[Formula: see text]RPM. The MRR range found was between 30.57[Formula: see text]mg/min and 53.11[Formula: see text]mg/min with Ra values ranging between 2.66[Formula: see text][Formula: see text]m and –5.76[Formula: see text][Formula: see text]m. The variation of machining with ECDD tool and bare ECD tool has also been graphically represented which highlights the benefits of diamond abrasive-based ECDD tool.

Advanced Optimization of Surface Characteristics and Material Removal Rate for Biocompatible Ti6Al4V Using WEDM Process with BBD and NSGA II.

Machining titanium alloy (Ti6Al4V) used in orthopedic implants via conventional metal cutting processes is challenging due to excessive cutting forces, low surface integrity, and tool wear. To overcome these difficulties and ensure high-quality products, various industries employ wire electrical discharge machining (WEDM) for precise machining of intricate shapes in titanium alloy. The objective is to make WEDM machining parameters as efficient as possible for machining the biocompatible alloy Ti6Al4Vusing Box-Behnken design (BBD) and nondominated sorting genetic algorithm II (NSGA II). A quadratic mathematical model is created to represent the productivity and the quality factor (MRR and surface roughness) in terms of varying input parameters, such as pulse active (Ton) time, pulse inactive (Toff) time, peak amplitude (A) current, and applied servo (V) voltage. The established regression models and related prediction plots provide a reliable approach for predicting how the process variables affect the two responses, namely, MRR and SR. The effects of four process variables on both the responses were examined, and the findings revealed that the pulse duration and voltage have a major influence on the rate at which material is removed (MRR), whereas the pulse duration influences quality (SR). The tradeoff between MRR and SR, when significant process factors are included, emphasizes the need for a reliable multi-objective optimization method. The intelligent metaheuristic optimization method named nondominated sorting genetic algorithm II (NSGA II) was utilized to provide pareto optimum solutions in order to achieve high material removal rate (MRR) and low surface roughness (SR).

Synthesis of Al-5Ti-1B-1Ce alloy from remelted chips and its refinement effect

The recycling of aluminum and titanium machining chips has always been a challenge. Here, a new recycling method is proposed. Al-5Ti-1B-1Ce alloy was prepared by the melt reaction method by using Al and TC4 machining chips as the main raw materials. The effects of reaction temperature and time on the phase structure were investigated. Al-5Ti-1B-1Ce prepared from remelted chips has effect refinement to pure aluminum. The addition of 0.3 wt% Al-5Ti-1B-1Ce to the aluminum melt refines the pure aluminum grains form 3000 μm to 185.2 μm and keep 60 min without growing. Besides, the addition of Ce optimizes the morphology and distribution of the second phase, which improve the refine ability of Al-5Ti-1B-1Ce.

Hole processing in parts made of titanium alloys

The features of machining of titanium alloys by cutting are considered. Measures are developed to improve the machinability of these alloys. It is shown that a decrease in the vibration amplitudes of the machine—fixture—tool—part (MFTP) technological system during cutting can significantly increase the machinability of such materials. Methods are given to increase the vibration resistance of the MFTP system, the accuracy of processing and tool life when threading with taps and drilling, namely: reducing the contact area of the tool with the workpiece in the cutting zone; increasing the strength and stiffness of the tool itself. It is indicated that the first method is the main one for increasing the tool life and the quality of hole processing. Taking this into account, patented high-performance designs of taps and attachments, drills are developed. The results of their tests are presented. Keywords: titanium alloys, machinability of titanium alloys, processing of holes, taps, drills for titanium machining. ragus05@mail.ru

A new elastic abrasive jet machining method for post–treatment of tool coatings: A case study on TiAlN coated tools for titanium machining

This paper investigates the effect of post–treatment by a newly–developed elastic abrasive jet machining (EAJM) method on the TiAlN coated tools. It employs the self–developed multi–element polymer beads as abrasives in air jet machining. The results indicate that post–treatment with EAJM can prominently improve the coating properties. Additionally, the wear resistance is improved as the tool wear is reduced up to 19%. While the wear resistance can be improved with increasing EAJM parameters, it can be diminished if the EAJM parameters exceed a proper range. Statistical analysis shows that the effect of EAJM on tool performance depends on the product of jetting time and pressure. The proper selection should range from 0.56 × 104 kPa·s to 2.96 × 104 kPa·s.

Specificity of the stress-strain and thermodynamic state simulation of the titanium alloy workpiece in the cutting zone

Titanium alloys have specific mechanical and physical-chemical properties that significantly reduce their machinability. Providing high productivity and accuracy has a great sense at the stage of technological preparation of machine-building production, taking into account the high cost of products from titanium alloys, as well as the need to provide increased operational properties. Simulation of machining processes of titanium alloys has many differences from the simulation of cutting of medium-carbon steels. This article focuses on recommendations for selecting an effective cutting model, describing the specific rheological properties of titanium alloys, optimizing solver selection, and cutting fracture criteria. The stages of adiabatic shear are described. The use of these recommendations contributes to the development of a more adequate model of machining titanium alloys and the choice of optimal cutting parameters to ensure a given quality of the machined surface layer of the workpiece.