Modern Metals Machining Technology

1966 ◽  
Vol 88 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Robert L. Vaughn
Keyword(s):  
Titanium Alloys ◽  
High Speed ◽  
Metal Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Tool Material ◽  
Cutting Fluid ◽  
Tool Geometry ◽  
Cutter Life ◽  
Cutting Operation

Titanium alloys such as A-110AT, B-120VCA, C-120AV, and 6-6-2AVT, which have been used to manufacture structural components for the aerospace industry, are difficult to machine when compared to aluminum and even some steel alloys. Tool wear for high-speed tool steel and carbide cutters takes place rapidly, necessitating the use of low cutting speeds and feeds to obtain a reasonable cutter life. In this study, the means used toward achieving an objective of increased producibility and reduced costs for titanium alloys was through an intensive machinability investigation of the machining characteristics. Control of pertinent machining variables, such as cutting speed, feed rate, tool material, tool geometry, machine tool setup, and cutting fluid, was rigorously maintained. Comparative cost analyses of the actual cutting operation and the attendant cutting tool costs were made concurrently with the study to obtain conditions which provided the best metal removal rate with reasonable cutter life at the lowest cost.

Comparison between EBM and DMLS Ti6Al4V Machinability Characteristics under Dry Micro-Milling Conditions

2016 ◽  
Vol 836-837 ◽  
pp. 177-184 ◽  
Author(s):  
Zdenka Rysava ◽  
Stefania Bruschi
Keyword(s):  
Titanium Alloys ◽  
Surface Defects ◽  
Removal Rate ◽  
Cutting Speed ◽  
Micro Milling ◽  
Burr Formation ◽  
Tool Geometry ◽  
Work Piece ◽  
Dry Cutting ◽  
High Flexibility

This paper is aimed at evaluating the micro-machinability of the Ti-6Al-4V titanium alloy made by the means of two different Additive Manufacturing (AM) technologies. AM comprises promising technologies, widely used especially to produce parts made of difficult-to-cut materials, such as the titanium alloys. Titanium alloys represent one of the most widely used materials in the biomedical field, thanks to the high biocompatibility and excellent mechanical characteristics. Even if near-net-shape parts can be produced through AM, semi-finishing and/or finishing machining operations may be necessary to obtain the required surface finish and geometrical tolerances. Micro-milling technique is a soliciting solution for this kind of application due to its high flexibility, elevated material removal rate and direct contact between the tool geometry and work piece. Nevertheless, there are deficiencies in the literature regarding the study of micro-machinability of materials produced by means of AM technologies. In this paper, the micro-machinability of the Ti-6Al-4V alloy obtained by two different AM technologies, namely Electron Beam Melting (EBM) and Direct Metal Laser Sintering (DMLS), was studied and compared in order to assess the influence of the material as-delivered condition. Micro-milling tests were conducted on a high-precision 5-axis Kugler™ micro-milling centre under dry cutting conditions, by using uncoated, two fluted, flat-end-square, tungsten carbide tools with a diameter of 300 microns. The full immersion slotting strategy was chosen under full factorial design of experiments with two factors (cutting speed and feed per tooth). The micro-machinability was evaluated in terms of burr formation, surface integrity (surface topography and surface defects), tool damage and microstructure alterations.

scholarly journals Multi-Response Optimization in High-Speed Machining of Ti-6Al-4V Using TOPSIS-Fuzzy Integrated Approach

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1104 ◽  
Author(s):  
Adel T. Abbas ◽  
Neeraj Sharma ◽  
Saqib Anwar ◽  
Monis Luqman ◽  
Italo Tomaz ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
High Speed ◽  
Removal Rate ◽  
Cutting Speed ◽  
Optimal Solution ◽  
Cutting Parameters ◽  
Integrated Approach ◽  
High Heat ◽  
Depth Of Cut ◽  
Cutting Processes

Titanium alloys are widely used in various applications including biomedicine, aerospace, marine, energy, and chemical industries because of their superior characteristics such as high hot strength and hardness, low density, and superior fracture toughness and corrosion resistance. However, there are different challenges when machining titanium alloys because of the high heat generated during cutting processes which adversely affects the product quality and process performance in general. Thus, optimization of the machining conditions while machining such alloys is necessary. In this work, an experimental investigation into the influence of different cutting parameters (i.e., depth of cut, cutting length, feed rate, and cutting speed) on surface roughness (Rz), flank wear (VB), power consumption as well as the material removal rate (MRR) during high-speed turning of Ti-6Al-4V alloy is presented and discussed. In addition, a backpropagation neural network (BPNN) along with the technique for order of preference by similarity to ideal solution (TOPSIS)-fuzzy integrated approach was employed to model and optimize the overall cutting performance. It should be stated that the predicted values for all machining outputs demonstrated excellent agreement with the experimental values at the selected optimal solution. In addition, the selected optimal solution did not provide the best performance for each measured output, but it achieved a balance among all studied responses.

Tool-Life Optimization in High-Speed Milling of Aeronautical Aluminum Alloy 7050-T7451

2009 ◽  
Vol 626-627 ◽  
pp. 117-122
Author(s):  
Y.Z. Pan ◽  
Xing Ai ◽  
Jun Zhao ◽  
X.L. Fu
Keyword(s):  
Aluminum Alloy ◽  
Tool Life ◽  
High Speed ◽  
Metal Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Least Square ◽  
High Speed Milling ◽  
Solid Carbide ◽  
Multi Linear Regression

A new approach is presented to optimize the tool life of solid carbide end mill in high-speed milling of 7050-T7451 aeronautical aluminum alloy. In view of this, the multi-linear regression model for tool life has been developed in terms of cutting speed and feed per tooth by means of central composite design of experiment and least-square techniques. Variance analyses were applied to check the adequacy of the predictive model and the significances of the independent parameters. Response contours of tool life and metal removal rates were generated by using response surface methodology (RSM). The analysis results show that it is possible to select an optimum combination of cutting speed and feed per tooth that improves metal removal rate without any sacrifice in tool life.

Tool Wear Characteristics for Near-Dry Cutting of Inconel 718

2014 ◽  
Vol 625 ◽  
pp. 282-287 ◽  
Author(s):  
Tatsuya Wakabayashi ◽  
Yukio Maeda ◽  
Kenichi Iwatsuka ◽  
Takanori Yazawa
Keyword(s):  
Tool Wear ◽  
Inconel 718 ◽  
Bending Strength ◽  
Removal Rate ◽  
Cutting Speed ◽  
Tool Material ◽  
Combustion Efficiency ◽  
Cutting Fluid ◽  
Cutting Stock ◽  
Dry Cutting

In recent years, high-combustion-efficiency jet engines are required in the aircraft industry. Inconel 718, which has excellent mechanical and chemical characteristics. However, Inconel 718 is difficult to cut material because of its low-thermal conductivity. Consequently, Wet cutting is ordinarily adopted to reduce the heat on cutting heat edge in Inconel 718 cutting. Wet cutting which uses large amount of cutting fluid requires much cost and energy on maintenance or disposal of cutting fluid, and this method is environmentally-unfriendly. From the view point of reducing cost and environmental load, we examined the method of Near-Dry cutting which uses very small amount of cutting fluid for the cylindrical cutting of Inconel 718. However, this method has some problems, such as tool wear and cutting stock removal rate. In this report, we experimentally examined the relationship between cutting speed, tool materials, and tool fracture of near-dry cutting of Inconel 718. We compared these results with those of wet cutting, a method which is more expensive, requires significantly greater amounts of energy, and is less environment-friendly. The results indicate that when cutting speed is 100 m/min, tool fracture occurs at a cutting distance of 200 m. When cutting speed is 50 m/min, tool fracture does not occur and near-dry cutting distances can continue beyond 600 m. Moreover, tool wear could be reduced when S05 tool material, which has high bending strength, was used.

Development of an Intelligent System for Tool Materials Selection in High Speed Machining

2004 ◽  
Vol 471-472 ◽  
pp. 82-86
Author(s):  
Zhan Qiang Liu ◽  
Xiu Guang Peng ◽  
J.G. Liu
Keyword(s):  
High Speed ◽  
Metal Removal ◽  
Intelligent System ◽  
Material Selection ◽  
Removal Rate ◽  
Tool Material ◽  
Case Based Reasoning ◽  
High Speed Machining ◽  
Tool Materials ◽  
Case Based

Tool materials play one of the pivotal roles in the machining system. Tool materials must be carefully chosen in relation to the workpiece material to be machined, the tool life, the metal removal rate, the machining cost, and the required accuracy and finish. The advantages and decision-making processes of case-based reasoning (CBR) are described. The CBR system for tool material selection in high speed machining (HSM) is developed. The case expression and organization, searching, matching and constraint-based adaptation rules are presented. With combining the case-based reasoning strategy and constraint-based adaptation, the tool material can be properly selected on the basis of previously successful tool materials used in HSM operations, which is helpful to push the wide applications of HSM.

Advances in the Turning of Titanium Alloys with Carbide and Superabrasive Cutting Tools

2016 ◽  
Vol 1135 ◽  
pp. 234-254 ◽  
Author(s):  
Rosemar Batista da Silva ◽  
Márcio Bacci da Silva ◽  
Wisley Falco Sales ◽  
Emanuel Okechukwu Ezugwu ◽  
Álisson Rocha Machado
Keyword(s):  
Titanium Alloys ◽  
Metal Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Manufacturing Cost ◽  
Machining Time ◽  
Significant Difference ◽  
Pcd Tools ◽  
Coated Carbide

Machining efficiency of titanium alloys is crucial to the aerospace industry especially in the manufacture of bladed discs (blisks) where over 80% of titanium alloy material is roughed out to generate the complex shapes and contours of components. The choice of the right tool materials for machining titanium alloys contributes enormously to reducing the overall machining time by significantly lowering the cycle time and indexing of the cutting edges. These improvements lead to a reduction of the manufacturing cost by up to 30%. Uncoated and coated carbide tools have demonstrated encouraging performances when turning Ti-6Al-4V alloy, especially under roughing operations complemented by high pressure cooling technology, at high cutting speed and depth of cut conditions that increase the metal removal rate. Under such cutting conditions there is no significant difference in performance between coated or uncoated carbide tools when turning Ti-6Al-4V alloy. Super abrasives like ceramics and cubic boron nitride (CBN) tools are not suitable for machining titanium alloys as low tool life with no economic benefit is achieved because of severe chipping and fracture of the cutting edge. Machined surfaces produced with ceramic tools have very low surface integrity status because of loss of form as a result of accelerated tool wear and the consequent chipping and fracture encountered during machining. Polycrystalline diamond (PCD) tools are suitable for finish turning Ti-6Al-4V alloy at cutting speeds up to 250 m/min.

Performance Analysis of Trihexyltetradecylphosphonium Chloride Ionic Fluid under MQL Condition in Hard turning

2020 ◽  
Vol 17 (1) ◽  
pp. 7629-7647
Author(s):  
A. Pandey ◽  
R. Kumar ◽  
A. K. Sahoo ◽  
A. Paul ◽  
A. Panda
Keyword(s):  
Material Removal Rate ◽  
Feed Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Coconut Oil ◽  
Chip Morphology ◽  
Weight Fraction ◽  
Cutting Fluid ◽  
Depth Of Cut

The current research presents an overall performance-based analysis of Trihexyltetradecylphosphonium Chloride [[CH3(CH2)5]P(Cl)(CH2)13CH3] ionic fluid mixed with organic coconut oil (OCO) during turning of hardened D2 steel. The application of cutting fluid on the cutting interface was performed through Minimum Quantity Lubrication (MQL) approach keeping an eye on the detrimental consequences of conventional flood cooling. PVD coated (TiN/TiCN/TiN) cermet tool was employed in the current experimental work. Taguchi’s L9 orthogonal array and TOPSIS are executed to analysis the influences, significance and optimum parameter settings for predefined process parameters. The prime objective of the current work is to analyze the influence of OCO based Trihexyltetradecylphosphonium Chloride ionic fluid on flank wear, surface roughness, material removal rate, and chip morphology. Better quality of finish (Ra = 0.2 to 1.82 µm) was found with 1% weight fraction but it is not sufficient to control the wear growth. Abrasion, chipping, groove wear, and catastrophic tool tip breakage are recognized as foremost tool failure mechanisms. The significance of responses have been studied with the help of probability plots, main effect plots, contour plots, and surface plots and the correlation between the input and output parameters have been analyzed using regression model. Feed rate and depth of cut are equally influenced (48.98%) the surface finish while cutting speed attributed the strongest influence (90.1%). The material removal rate is strongly prejudiced by cutting speed (69.39 %) followed by feed rate (28.94%) whereas chip reduction coefficient is strongly influenced through the depth of cut (63.4%) succeeded by feed (28.8%). TOPSIS significantly optimized the responses with 67.1 % gain in closeness coefficient.

Effects of Cooling Conditions on Thermal Crack Initiation of Brittle Cutting Tools during Intermittent Cutting

2015 ◽  
Vol 656-657 ◽  
pp. 237-242
Author(s):  
Kenji Yamaguchi ◽  
Tsuyoshi Fujita ◽  
Yasuo Kondo ◽  
Satoshi Sakamoto ◽  
Mitsugu Yamaguchi ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Thermal Shock ◽  
High Speed ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Condition ◽  
Thermal Crack ◽  
Cooling Conditions ◽  
Cutting Operation ◽  
Intermittent Cutting

It is well known that a series of cracks running perpendicular to the cutting edge are sometimes formed on the rake face of brittle cutting tools during intermittent cutting. The cutting tool is exposed to elevated temperatures during the periods of cutting and is cooled quickly during noncutting times. It has been suggested that repeated thermal shocks to the tool during intermittent cutting generate thermal fatigue and result in the observed thermal cracks. Recently, a high speed machining technique has attracted attention. The tool temperature during the period of cutting corresponds to the cutting speed. In addition, the cooling and lubricating conditions affect the tool temperature during noncutting times. The thermal shock applied to the tool increases with increasing cutting speed and cooling conditions. Therefore, to achieve high-speed cutting, the evaluation of the thermal shock and thermal crack resistance of the cutting tool is important. In this study, as a basis for improving the thermal shock resistance of brittle cutting tools during high-speed intermittent cutting from the viewpoint of cutting conditions, we focused on the cooling conditions of the cutting operation. An experimental study was conducted to examine the effects of noncutting time on thermal crack initiation. Thermal crack initiation was found to be restrained by reducing the noncutting time. In the turning experiments, when the noncutting time was less than 10 ms, thermal crack initiation was remarkably decreased even for a cutting speed of 500 m/min. In the milling operation, the number of cutting cycles before thermal crack initiation decreased with increasing cutting speed under conditions where the cutting speed was less than 500 m/min. However, when the cutting speed was greater than 600 m/min, thermal crack initiation was restrained. We applied the minimal quantity lubrication (MQL) coolant supply to the intermittent cutting operation. The experimental results showed that the MQL diminished tool wear compared with that under the dry cutting condition and inhibited thermal crack initiation compared with that under the wet cutting condition.

Multiresponse Optimization of Al Alloy-SiC Composite Machining Parameters for Minimum Tool Wear and Maximum Metal Removal Rate

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Rajesh Kumar Bhushan
Keyword(s):  
Tool Wear ◽  
Metal Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Al Alloy ◽  
Machining Parameters ◽  
Metal Removal Rate ◽  
Nose Radius ◽  
Multiresponse Optimization

Optimization in turning means determination of the optimal set of the machining parameters to satisfy the objectives within the operational constraints. These objectives may be the minimum tool wear, the maximum metal removal rate (MRR), or any weighted combination of both. The main machining parameters which are considered as variables of the optimization are the cutting speed, feed rate, depth of cut, and nose radius. The optimum set of these four input parameters is determined for a particular job-tool combination of 7075Al alloy-15 wt. % SiC (20–40 μm) composite and tungsten carbide tool during a single-pass turning which minimizes the tool wear and maximizes the metal removal rate. The regression models, developed for the minimum tool wear and the maximum MRR were used for finding the multiresponse optimization solutions. To obtain a trade-off between the tool wear and MRR the, a method for simultaneous optimization of the multiple responses based on an overall desirability function was used. The research deals with the optimization of multiple surface roughness parameters along with MRR in search of an optimal parametric combination (favorable process environment) capable of producing desired surface quality of the turned product in a relatively lesser time (enhancement in productivity). The multi-objective optimization resulted in a cutting speed of 210 m/min, a feed of 0.16 mm/rev, a depth of cut of 0.42 mm, and a nose radius of 0.40 mm. These machining conditions are expected to respond with the minimum tool wear and maximum the MRR, which correspond to a satisfactory overall desirability.

Highlights of the DARPA Advanced Machining Research Program

1985 ◽  
Vol 107 (4) ◽  
pp. 325-335 ◽  
Author(s):  
R. Komanduri ◽  
D. G. Flom ◽  
M. Lee
Keyword(s):  
Thermal Properties ◽  
Tool Wear ◽  
Titanium Alloys ◽  
Tool Life ◽  
Research Program ◽  
High Speed ◽  
Metal Removal ◽  
High Speed Machining ◽  
Advanced Machining ◽  
Nickel Base

Results of a four-year Advanced Machining Research Program (AMRP) to provide a science base for faster metal removal through high-speed machining (HSM), high-throughput machining (HTM) and laser-assisted machining (LAM) are presented. Emphasis was placed on turning and milling of aluminum-, nickel-base-, titanium-, and ferrous alloys. Experimental cutting speeds ranged from 0.0013 smm (0.004 sfpm) to 24,500 smm (80,000 sfpm). Chip formation in HSM is found to be associated with the formation of either a continuous, ribbon-like chip or a segmental (or shear-localized) chip. The former is favored by good thermal properties, low hardness, and fcc/bcc crystal structures, e.g., aluminum alloys and soft carbon steels, while the latter is favored by poor thermal properties, hcp structure, and high hardness, e.g., titanium alloys, nickel base superalloys, and hardened alloy steels. Mathematical models were developed to describe the primary features of chip formation in HSM. At ultra-high speed machining (UHSM) speeds, chip type does not change with speed nor does tool wear. However, at even moderately high speeds, tool wear is still the limiting factor when machining titanium alloys, superalloys, and special steels. Tool life and productivity can be increased significantly for special applications using two novel cutting tool concepts – ledge and rotary. With ledge inserts, titanium alloys can be machined (turning and face milling) five times faster than conventional, with long tool life (~ 30 min) and cost savings up to 78 percent. A stiffened rotary tool has yielded a tool life improvement of twenty times in turning Inconel 718 and about six times when machining titanium 6A1-4V. Significantly increased metal removal rates (up to 50 in.3/min on Inconel 718 and Ti 6A1-4V) have been achieved on a rigid, high-power precision lathe. Continuous wave CO2 LAM, though conceptually feasible, limits the opportunities to manufacture DOD components due to poor adsorption (~ 10 percent) together with high capital equipment and operating costs. Pulse LAM shows greater promise, especially if new laser source concepts such as face pump lasers are considered. Economic modeling has enabled assessment of HSM and LAM developments. Aluminum HSM has been demonstrated in a production environment and substantial payoffs are indicated in airframe applications.

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