Machining Of Ti6Al4V Alloy Research Articles

CFD aided finite element modeling for spot cooled vibration assisted turning of Ti6Al4V alloy

Machining of titanium alloys using hybrid cutting techniques is acquiring importance now-a-days due to the benefits of integrating two or more processes. This study explores such a novel in-house developed hybrid cutting technique, which is a combination of ultrasonic assistance and vortex tube based spot cooling with CO2 gas as coolant for machining Ti6Al4V alloy. CFD aided finite element model was developed and experimentally validated for this novel technique termed spot cooled vibration assisted turning (SCVAT). Parametric study of cooling (nozzle inclination, nozzle tool distance, nozzle diameter, coolant pressure and cold fraction), vibration (amplitude) and machining parameters was carried out in order to identify the role of each parameter on cutting force and cutting temperature. The parametric study showed that flow variables (cold fraction and coolant pressure) are more significant than nozzle variables in influencing cutting force and cutting temperature. SCVAT reduced cutting temperature by 21.66% and 3.45%, respectively, than VAT and spot cooling alone. However, cutting force reduced by 7.65% compared to spot cooling and increased by 11.78% compared to VAT. Overall observations from the CFD aided Finite element model revealed superior performance of SCVAT than its individual counterparts.

Effect of Deposition Parameters on Micromechanical Properties and Machining Performance of CrN Coating for Wet Finish Turning of Ti6Al4V Alloy.

This study aims to optimize the performance of CrN coatings deposited on WC cutting tools for machining Ti6Al4V alloy, where the formation of built-up edge (BUE) is a prevalent and critical issue. In-house CrN coatings were developed using the PVD (Physical Vapor Deposition) process, with variations in deposition parameters including nitrogen gas pressure, bias voltage, and coating thickness. A comprehensive experimental approach encompassing deposition, characterization, and machining performance evaluation was employed to identify the optimal deposition conditions. The results indicated that CrN coatings deposited at a nitrogen gas pressure of 4 Pa, a bias voltage of -50 V, and a thickness of 1.81 µm exhibited superior performance, significantly reducing BUE formation and tool wear. These optimized coatings demonstrated enhanced properties, such as a higher elastic modulus and a lower coefficient of friction, which contributed to improved tool life and machining performance. Comparative studies with commercial CrN coatings revealed that the in-house developed coatings outperformed the commercial variants by approximately 65% in tool life, owing to their superior mechanical properties and reduced friction. This research highlights the potential of tailored CrN coatings for advanced machining applications and emphasizes the importance of optimizing deposition parameters to achieve high-performance tool coatings.

Machinability of Ti6Al4V Alloy: Tackling Challenges in Milling Operations

This study investigates strategies for improving the 3D milling of Titanium Alloy Grade 5 (Ti6Al4V) by optimizing machining parameters and cutting tool engagement techniques. Ti6Al4V presents significant machining challenges due to its low machinability index (20%), which directly impacts manufacturing efficiency. High temperatures during machining, often exceeding 8820C, lead to phase transformations, creating a harder Beta lamellar equiaxed microstructure. This, coupled with the alloy's poor thermal conductivity, results in heat concentration at the cutting tool interface, accelerating thermo-chemical wear and potentially catastrophic tool failure. This study explores how controlled cooling methods, coupled with appropriate lubrication, can effectively dissipate heat and flush away chips, mitigating the detrimental effects of high temperatures. Furthermore, the selection of cutting tool materials and coatings with high thermal conductivity and chemical inertness, along with aggressive rake angles and higher relief angles, are examined as methods to improve shearing, minimize smearing, and enhance surface quality. By optimizing these parameters, this study aims to provide manufacturers with practical strategies to overcome the challenges of Ti6Al4V machining, ultimately increasing tool life and overall milling efficiency.

Machinability of Ti6Al4V Alloy: Tackling Challenges in Milling Operations

This study extensively elaborates the approach towards making ease in 3D milling of Titanium Alloy Grade 5; by adapting the controlled parameters and specific strategies in cutting tool encroachment in milling. Every manufacturer is anxious about the machinability index (20%) of Ti6Al4V, which affects the machining efficiency proportionally. During machining, Phase alteration above the 8820C produces a Beta lamellar equiaxed microstructure, which is hard; also, limited thermal conductivity allows the generated heat towards the cutting tool to lead the Thermo-assisted wear. Higher temperatures also initiated chemically eagerness of Ti6Al4V and reacted with cutting tool edge and escorts towards catastrophic failure. The difficult Machinability demonstrates the detrimental notable effect on the cutting tool's health and follows the Ti6Al4V surface quality. The Cooling methods can flush out chips and frictional heat with ample lubrication, desirably controlling the worse effect of Machinability to some extent blissfully. The cutting tool material and coating, has chemically inert and excellent thermal conductivity with an aggressive rake angle with higher relief angle, improves the shearing tendency of Ti6Al4V by avoiding smearing, ultimately speculated surface quality with desired Tool life through higher Machining efficiency in milling.

Investigation of tool wear and energy consumption in machining Ti6Al4V alloy with uncoated tools

This research studies the energy consumption and wear mechanism of carbide cutting tools in dry machining of Ti6Al4V alloy. In the first phase of experiments, full factorial design experiments were employed to study the tool wear rate (R) and specific cutting energy (SCE) with respect to the machining conditions (cutting speed and feed rate). Results showed that machining responses such as tool wear and energy consumption are affected by cutting conditions, thus requiring investigation to understand the wear mechanisms. Therefore, in the second phase, additional experiments were performed to investigate the tool-workpiece interactions at the cutting conditions reported to have low, moderate, and high tool wear. It was revealed that strong adhesion and material transfer between the tool and workpiece caused high wear. Electron dispersive X-ray spectroscopy (EDX) analysis of worn tools showed that the transfer of tungsten (W) and cobalt (Co) to the workpiece and titanium to the tool surface is the primary cause of tool deterioration. As a result, diffusion and dissolution have degraded cutting performance and weakened the tool edge, leading to rapid wear. Furthermore, worn tools resulted in relatively higher energy consumption per unit volume of material removed at the tooltip. The degradation of cutting performance and weakening of the tool edge results in rapid wear and higher energy consumption. The study suggests that minimizing tool wear is crucial for energy reduction, improved sustainability, and cleaner production goals in dry machining of titanium-based alloys.

Finite element investigation of cutting speed effects on the machining of Ti6Al4V alloy

In modern times, titanium alloy has a great application prospect in the medical field. Still, the pitiful machinability of titanium alloy material brings incredible difficulty to its ultra-precision cutting. This work presented the effect of parametric sensitivity analysis of the orthogonal cutting process using the finite element method, which dramatically enhances the cutting performance of Ti–6AL–4V. The simulation results are attained by applying Abaqus® explicit 6.14 software. The mechanical reaction of two-dimensional finite element models has been examined for cutting forces. Additionally, the impacts of rake angle, clearance angle, and nose radius on the stress distribution in orthogonal cutting of Ti–6AL–4V have been investigated. Also, to make certain numerical accuracy, the Johnson–Cook constitutive models for Ti6Al4V alloy are implemented. In the end, FE simulation outcomes were supported by the reported results in the literature.

Investigation of sustainable strategies with metaheuristic algorithm on surface roughness, cutting temperature, and chip morphology during machining of Ti6Al4V alloy

Investigation of sustainable strategies with metaheuristic algorithm on surface roughness, cutting temperature, and chip morphology during machining of Ti6Al4V alloy

Investigation of sustainable strategies with metaheuristic algorithm on surface roughness, cutting temperature, and chip morphology during machining of Ti6Al4V alloy

Investigation of sustainable strategies with metaheuristic algorithm on surface roughness, cutting temperature, and chip morphology during machining of Ti6Al4V alloy

Assessment of Machinability of Ti6Al4V Alloy Under Dry Conditions

Titanium alloys pose significant challenges during machining, necessitates a thorough investigation into the impact of process parameters on machining Ti6Al4V alloy. This study investigates into the machinability of Ti6Al4V alloy under dry machining conditions using uncoated tools. The experimental design studiedthe effect of process parameters on the cutting power, surface roughness and material removal rate during dry machining of Ti6Al4V alloy. Utilizing Taguchi design of experiments, unified cutting experiments were conducted under dry conditions employing uncoated tools. The study findings revealed that optimal cutting parameters lead to improved cutting energy consumption, reduced tool wear, and enhanced surface finish and material rates. Analysis of Variance (ANOVA) and regression modelling were employed to obtain an objective function capable of predicting the best cutting conditions. ANOVA showed that cutting speed is the main factor for an increase in the cutting power with major contribution of 73 % whereas feed rate is the key factor for surface roughness with the contribution of 80 %. These results help to gain the advantages of dry machining under optimal conditions, facilitating clean production with minimal energy consumption and improved surface quality.

Evaluation of tribological interactions and machinability of Ti6Al4V alloy during finish turning under different cooling conditions

The titanium alloy Ti6Al4V has several applications and is considered as a difficult-to-machine material. This study evaluates some tribological interactions in finish turning of Ti6Al4V titanium alloy, including the tool wear, and coefficient of friction in tool-chip interface. Subsequently, the machinability of Ti6Al4V titanium alloy has been investigated, considering the chip geometry, chip thickness ratio, as well as changes in the total cutting force components. The turning process was carried out over a wide range of the feed rate (f) and depths of cut (ap) using hard carbide, GC1115 grade, inserts with double-layer PVD coating. The finish turning tests were conducted under the dry, flood, and MQL (minimum quantity lubrication) cutting conditions. It was found that favorable chip shapes (arc loose) were obtained in the range ap = 0.9–1.2 mm and f = 0.25–0.4 mm/rev. Increasing the f clearly affects the formation of a serrated chip. In addition, the intensity of tool wear, as well as the variations of cutting forces and chip thickness ratios were strongly affected by the applied cooling/lubricating condition. Compared to wet conditions, the Kh values decrease by ∼22 % with dry machining and by ∼12 % with MQL. Compared to wet conditions, for dry machining the cutting forces decrease to 70 % and with MQL to 8 %. The cumulative wear rate under dry machining increases by 18 % compared to wet conditions, and with MQL reduces by 19 %.

Analysis of cutting forces at different spindle speeds with straight and helical-flute tools for conventional-speed milling incorporating the effect of tool runout

This paper is concerned with the experimental investigation and mechanistic prediction of cutting forces for flat-end milling with tool runout. The effects of the tool geometry, the workpiece material and cutting parameters such as spindle speed, tool engagement and cutting direction are investigated. The mechanistic force model uses the trochoidal flute path to calculate the undeformed chip thickness. Average cutting force and linear regression model are applied for identifying the coefficients of the force model, and tool runout parameters are established from the radii of all flutes at the free end of the cutting tool. A series of milling processes are conducted on AZ31 Magnesium (Mg) alloy and titanium alloy (Ti6Al4V) to analyze the instantaneous cutting force curves, amplitudes of cutting forces and peak forces over a wide range of conventional spindle speeds, namely 600, 1200 and 3000 rev/min. It is found that the values of the cutting force coefficients are higher at lower spindle speed and decrease with an increase in spindle speed, especially when machining Ti6Al4V alloy. For the edge force coefficients, it is observed a slight variation when using cutting tools with different helix angles. Besides, the cutting force amplitudes strongly depend upon the workpiece material. The helix angle has a significant influence on the transverse force amplitude at the spindle speed of 600 rev/min. The cutting forces obtained mechanistically are also substantiated by comparison with measurements.

Machinability of Ti6Al4V as influenced by cutting velocity, tool feed and cutting depth

Due to its application versatility, machining of Ti6Al4V alloy has been considered an important topic in the field of industrial manufacturing. To avoid machining-induced detrimental effects on the environment, dry machining of this difficult-to-machine alloy is a trending subject of matter. Therefore, the present study intends to explore different machinability indices such as tangential cutting force components, temperature evolved at tool-tip and wear of uncoated carbide inserts under the variations of machining parameters. A detailed study on tool wear modes and micro-morphology characteristics of evolved chips are also carried out for the present experimental analysis.

Neural network based model for estimating cutting force during machining of Ti6Al4V alloy

The evolving technology has pushed machine learning techniques to replace human smartness. A machine learning model is capable of learning and replicating like our brain. This approach of data-driven model is implemented to predict the cutting force in machining of Ti6Al4V. Titanium alloys are commonly used in high strength applications due to their excellent properties. These same properties make the machining of the titanium alloy complicated. An attempt has been made for finding the cutting force under minimum quantity lubrication (MQL). MQL is a sustainable manufacturing-based lubrication system. Taguchi’s approach was used to attain a full factorial design for combination of different parameters. Accordingly, a neural network (NN) model was developed which was capable of predicting cutting forces based on the trained model. The proposed model could be implemented to find optimal parameters in shortest duration, thereby eliminating the need for experimental computations.

RSM based expert system development for cutting force prediction during machining of Ti–6Al–4V under minimum quantity lubrication

In recent days the manufacturing process have become more precise and cost efficient due to advancement in the field of computer technology. Information technology has been integrated with manufacturing practice and has resulted in time reduction from concept of a product to marketing of the product. Cutting force generated is the main manufacturing issue raised among industries as it clearly affects quality and cost of the final product. Hence using extensive literature and data base knowledge optimum cutting parameters are selected. Therefore, this paper focuses on a response surface methodology (RSM) based expert system that has been developed using JAVA programming with the help of response surface second order model to automatically generate values of cutting force during machining of Ti–6Al–4V alloy under minimum quantity lubrication (MQL) for different process input parameters. From RSM it has been observed that calculated value of F (20.36) was greater than the F-table value (3.02) and hence the model developed can be effectively used for machining of Ti–6Al–4V alloy. Further the developed RSM based expert system model can be successfully used to predict the force generated during cutting process while machining Ti–6Al–4V alloy under MQL conditions.

Investigation of the Wear Performance of TiB2 Coated Cutting Tools during the Machining of Ti6Al4V Alloy.

The machining of Ti6Al4V alloy, especially at low cutting speeds, is associated with strong Built-Up Edge (BUE) formation. The PVD coatings applied on cutting tools to machine such materials must have the necessary combination of properties to address such an underlying wear mechanism. The present work investigates and shows that TiB2 PVD coating can be designed to have certain mechanical properties and tribological characteristics that improve machining in cases where BUE formation is observed. Three TiB2 coatings were studied: one low hardness coating and two high hardness coatings with varied coating thicknesses. Wear performances for the various TiB2 coated carbide tools were evaluated while rough turning Ti6Al4V. Tool wear characteristics were evaluated using tool life studies and the 3D wear volume measurements of the worn surface. Chip morphology analyses were done to assess the in-situ tribological performance of the coatings. The micro-mechanical properties of the coatings were also studied in detail to co-relate with the coatings’ performances. The results obtained show that during the rough turning of Ti6Al4V alloy with intensive BUE formation, the harder TiB2 coatings performed worse, with coating delamination on the rake surface under operation, whereas the softer version of the coating exhibited significantly better tool life without significant coating failure.

Machinability aspects in dry turning of Ti6Al4V alloy with HiPIMS coated carbide inserts

Owing to their unique mechanical properties, titanium alloys have been and will be used extensively in a myriad of industries ranging from aerospace to automotive to medical field. Hence, a continuous improvement in the performance of the coated inserts with hard materials capable of enhanced tribological and wear resistive properties is necessary. The present work contributes to investigation of the influence of cutting parameters in turning operations of the alpha-beta titanium alloy- Ti-6Al-4V. Tungsten carbide inserts of K20 grade is coated with TiAlN and AlCrN monolayer coatings by high power impulse magnetron sputtering (HPPMS). Machinability of Ti6Al4V alloy is studied at different cutting speed, feed ranging from 60 to 120 m/min and 0.1 to 0.25 mm/rev with constant depth of cut of 0.5 mm to evaluate the optimum turning parameters under dry environment. The tool wear is observed initially under an optical microscope and nature of wear is observed with scanning electron microscope (SEM). It is witnessed that the AlCrN coated inserts have an upper edge over the TiAlN coated inserts due to better adhesion and thermal stability of the coating. Tool wear and surface finish is found to be optimum at cutting speed of 100 m/min, feed of 0.1mm/rev and depth of cut 0.5 mm. The present will provide useful and economic machining solutions for the high speed machining of titanium alloys by effective utilization of coated tungsten carbide inserts.

Effect of microstructural change on cutting force fluctuation

Machining of aerospace and biomedical grade titanium alloys such as Ti6Al4V is always a challenge due to their low thermal conductivity and elastic modulus. Formation of localized shear bands during machining of Ti6Al4V alloy results in chip segmentation, which causes force variation on the cutting tool. An unconventional way is followed to study the effect of microstructural changes on cutting forces while machining Ti6Al4V alloy. Microstructure of the material was altered using static annealing and laser heat treatment. For static annealed material the study was focused on the effect of microstructure on machinability of Ti6Al4V alloys at different cutting speeds. The variation in force was observed to be smallest in the case of lower grain size samples subjected to machining.

Precision Hard Turning of Ti6Al4V Using Polycrystalline Diamond Inserts: Surface Quality, Cutting Temperature and Productivity in Conventional and High-Speed Machining.

This article presents the results of an experimental investigation into the machinability of Ti6Al4V alloy during hard turning, including both conventional and high-speed machining, using polycrystalline diamond (PCD) inserts. A central composite design of experiment procedure was followed to examine the effects of variable process parameters; feed rate, cutting speed and depth of cut (each at five levels) and their interaction effects on surface roughness and cutting temperature as process responses. The results revealed that cutting temperature increased with increasing cutting speed and decreasing feed rate in both conventional and high-speed machining. It was found that high-speed machining showed an average increase in cutting temperature of 65% compared with conventional machining. Nevertheless, high-speed machining showed better performance in terms of lower surface roughness despite using higher feed rates compared to conventional machining. High-speed machining of Ti6Al4V showed an improvement in surface roughness of 11% compared with conventional machining, with a 207% increase in metal removal rate (MRR) which offered the opportunity to increase productivity. Finally, an inverse relationship was verified between generated cutting temperature and surface roughness. This was attributed mainly to the high cutting temperature generated, softening, and decreasing strength of the material in the vicinity of the cutting zone which in turn enabled smoother machining and reduced surface roughness.

An experimental analysis of minimum chip thickness in micro-milling of two different titanium alloys

Micro-milling is a micro-mechanical cutting method used to obtain complex and three-dimensional micro geometries. Micro-cutting tools are used in the manufacturing of micro-components and the type of workpiece is also important for good surface quality and minimum burr. In this study, micro machinability of Ti6Al4V alloy which is used most frequently in micro-component production is compared with Ti5553 alloy. Micro-milling of Ti5553 alloy and comparison of the minimum chip thickness with Ti6Al4V were performed for the first time in this study. Using different cutting parameters, the variation of surface roughness, burr width, and cutting forces were investigated. The cutting tests were carried out on a specially designed and high-precision micro-milling test system using a TiCN-coated two-flute end mill of 0.6 mm diameter. According to the results, minimum chip thickness is approximately 0.3 times the edge radius of the cutting tool and does not vary with the alloy type. At feed rates smaller than the minimum chip thickness, both the cutting forces increase and the surface quality decreases. For both alloys, reduced feed rate and increased depth of cut lead to increased burr width. The burr widths in Ti6Al4V alloy are higher. At the end of the study, the limits of the cutting parameters where plowing occurred for the both alloys are clearly determined. In addition, the limits of the cutting parameter causing plowing have been confirmed by cutting forces, surface roughness, and burr formation.

Finite element simulation-based predictive regression modeling and optimum solution for grain size in machining of Ti6Al4V alloy: Influence of tool geometry and cutting conditions

The present research study was aimed at studying the impact of machining parameters on grain size alterations in machining of Ti6Al4V alloy using finite element analysis (FEA) based on the Johnson-Mehl-Avrami-Kolmogorov (JMAK) recrystallization model. The machining parameters consisted of both cutting conditions and tool geometry including cutting speed, feed rate, tool edge radius and rake angle. Three series of JMAK constants were used in the simulations and the degree of accuracy of the obtained results were compared. Finite element (FE) simulations were conducted for machining conditions designed using a D-optimal Design of Experiment (DoE). Analysis of Variance (ANOVA) was carried out to identify the most effective machining parameters on the responses of average grain size (AGS), machining temperature (MT), cutting force (CF), and feed force (FF). Next, Response Surface Method (RSM) was used to predict regression models of AGS, MT, CF, and FF. The optimal values of machining parameters were obtained to improve AGS, MT, CF, and FF. The ANOVA results showed that rake angle and cutting speed were, respectively, the most and least significant parameters affecting AGS in the design space. Rake angle was the most effective parameter influencing all of the responses. The single-criterion optimization of AGS provided a small improvement in AGS with a high increase in material removal rate (MRR). The results of the multi-criteria optimization of AGS, MT, CF, and FF demonstrated that machining of Ti6Al4V alloy with a tool having a medium cutting edge radius and high positive rake angle at a medium cutting speed and a low feed rate in the design space produced finer grains along with reduced CF and FF and an unchanged MT.