3D Numerical Investigation of Effect of Milling Process Parameters on High Speed Milling of Ti-Al6-V4

2012 ◽  
Author(s):  
J. Ma ◽  
Shuting Lei ◽  
Huaqi Lu
Keyword(s):  
Titanium Alloy ◽  
Titanium Alloys ◽  
Numerical Investigation ◽  
Process Parameters ◽  
High Speed ◽  
Chemical Reactivity ◽  
Milling Process ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Axial Depth

Titanium alloys are widely used in aerospace industry owing to excellent mechanical properties. While because of high chemical reactivity and low thermal conductivity, titanium alloys are classified as hard-to-cut materials. In this paper, Finite Element Method (FEM) is employed to conduct numerical investigation in the effects of milling process parameters (milling speeds, feed per tooth, and axial depth of cut) on three-dimensional (3D) high speed milling of Titanium alloy (Ti-6Al-4V). The tool material used is Carbide and Johnson-Cook plastic model is employed to model the workpiece due to its capability of modeling large strains, high strain rates, and temperature dependent visco-plasticity. Different milling speeds, feed per tooth, and axial depth of cut are used to explore the effects of the milling process parameters on the cutting temperature, cutting forces, and power required for machining. This model provides fundamental understanding of cutting mechanics of the 3D high speed milling of Titanium alloy (Ti-6Al-4V).

Research on Stability of High Speed Milling System

2013 ◽  
Vol 670 ◽  
pp. 137-142
Author(s):  
Y.Y. Guo ◽  
H. Lei ◽  
C. Zhao ◽  
C.T. Sun
Keyword(s):  
High Speed ◽  
Metal Removal ◽  
Milling Process ◽  
Depth Of Cut ◽  
Engineering Practice ◽  
Model Parameters ◽  
High Speed Milling ◽  
Stability Lobes ◽  
The Stability ◽  
Axial Depth

Machining instability is often the limiting factor on metal removal rate. So the stability of cutting system is an important research in high-speed machining area. It is widely used in engineering practice. In this paper, the stability of high-speed milling was studied by the numbers aiming at the dynamic milling process model of ball-end mill. The dynamic model of high-speed milling process was established. On the basis of Altintas’s theory, the formula about the limit axial depth of cut was derived. Besides, the model parameters of the system were obtained and the accuracy of the stability lobes diagram was verified through the experiments. From this research, it was learned that structure parameters of machine tool-cutting tool system, cutting force coefficients, spindle speed and axial depth of cut were factors affecting the stability in high-speed cutting. And the obtained stability lobes diagram provided a reliable basis in selecting cutting parameters during tool path planning.

scholarly journals Effects of machining system parameters and dynamics on quality of high-speed milling

2013 ◽  
Author(s):  
◽  
Khaled A. M. Adem
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
End Milling ◽  
Milling Process ◽  
Depth Of Cut ◽  
Force Model ◽  
Cutting Force Coefficients ◽  
High Speed Milling ◽  
End Milling Process ◽  
Axial Depth

This dissertation outlines research on studying the effects of machining parameters such that cutting speed, feed rate, axial depth of cut, radial depth of cut and helix angle on system dynamic stability and the surface quality of high-speed milling. With the use of structural tool modal parameters, the material cutting force coefficients and the axial depth of cut, the system can avoid the chatter phenomenon of the tool at high cutting speeds. The surface roughness finish in the milling process is determined by the machining parameters and tool structure dynamics. To perform high-speed milling, the chance of tool vibration (chatter phenomenon) which affects the cutting tool, must be minimized or eliminated. In this research, the linear and nonlinear mathematical force models including the effect of the helix angle are presented for an end-milling process. The linear force model includes cutting-edge coefficients. The cutting force coefficients are determined for an end-milling process using two methods, the average force method and the optimization technique method. The second method is developed to identify the cutting force coefficients in the milling process by forming the objective functions using the optimization technique to minimize the error between the experimental and the analytical forces. Moreover, this method produced a good force model that approximates the experimental force results, which compared with the average force method. The stability lobe diagrams are created using the analytical method to determine whether the cut is stable or unstable. In addition, simulations are performed to predict stability of the milling process. By comparing simulated and experimental results, the dynamics and stability of the milling operation can be easily identified before performing any cutting operation. The slot milling experiments show that while the system in the chatter region close to the stability limits and the axial depth of cut increased, the system changes from stable chatter to chaotic chatter. Furthermore, the nature of bifurcation in milling is investigated by performing experiments and simulations. The linear and nonlinear mathematical force models are used for simulating end-milling process. Simulated bifurcation diagrams are generated using both models and compared to experimental results. In addition, the effect of the feed rate on the location of the bifurcation point (start and end of bifurcation) is studied. By comparing simulated and experimental results, the simulation using a nonlinear force model is found more accurate in predicting the dynamics and stability of the milling operation. The applications of Taguchi and response surface methodologies (RSM) are used to minimize the surface roughness in the end milling process. Taguchi’s method for optimum selection of the milling process parameters is applied based on the signal to noise ratio and ANOVA analysis of the surface finish. A second-order model contains quadratic terms that have been created between the cutting parameters and surface roughness using response surface methodology (RSM). Surface roughness of the machined surfaces are measured and used to identify the optimum levels of the milling parameters. Based on Taguchi, ANOVA, and RSM analyses, the end milling process can be optimized to improve surface finish quality and machining productivity.

An Experimental Investigation Into the High Speed Turning of Ti-6Al-4V Titanium Alloy

2010 ◽  
Author(s):  
Anil K. Srivastava ◽  
Jon Iverson
Keyword(s):  
Titanium Alloy ◽  
Titanium Alloys ◽  
High Speed ◽  
Elevated Temperatures ◽  
Chemical Reactivity ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Layered Coatings ◽  
High Specific Strength ◽  
Cutting Speeds

Titanium and its alloys have seen increased utilization in military and aerospace applications due to combination of high specific strength, toughness, corrosion resistance, elevated-temperature performance and compatibility with polymer composite materials. Titanium alloys are difficult to machine due to their inherent low thermal conductivity and higher chemical reactivity with other materials at elevated temperatures. In general, temperature related machining difficulties are encountered at production speeds in the range of 60 m/min and high-speed machining of these alloys has created considerable interest to researchers, tool manufacturers and end users. This paper provides recent results obtained during turning operation with the aim of improving machinability of titanium alloys. Several tests have been conducted using (i) micro-edge prep geometry of the inserts, (ii) ultra-hard PVD coated, and (iii) nano-layered coated inserts and the effects of speeds and feeds during turning of Ti-6Al-4V titanium alloy are discussed. The initial tests have been conducted under orthogonal (2-D) cutting conditions with no coolant application. Based on these results, several oblique cutting (3-D) tests have been designed and conducted to study the effect of various types of ultra-hard and nano-layered coatings at higher cutting speeds under flooded coolant conditions. The effects of speed and feed on cutting force and tool wear are presented in this paper.

Dynamics and Stability of Milling Process Considering the Gyroscopic Effects

2009 ◽  
Vol 76-78 ◽  
pp. 624-629 ◽  
Author(s):  
Shan Shan Sun ◽  
W.X. Tang ◽  
H.F. Huang ◽  
Xi Qing Xu
Keyword(s):  
High Speed ◽  
Milling Process ◽  
Depth Of Cut ◽  
Stability Lobe Diagram ◽  
High Speed Milling ◽  
Stability Lobe ◽  
Ultra High Speed ◽  
Resonance Response ◽  
Critical Depth Of Cut ◽  
Gyroscopic Effects

A dynamics model is established considering gyroscopic effects due to high speed rotating spindle-tool system in ultra-high speed milling (USM). The proposed method for predicting stability enables a new 3D stability lobe diagram to be developed in the presence of gyroscopic effects, to cover all the intermediate stages of spindle speed. The influences of the gyroscopic effects on dynamics and stability in USM are analyzed. It is shown that the gyroscopic effects lower the resonance response frequencies of the spindle-tool system and the stable critical depth of cut in ultra-high speed milling.

scholarly journals Analysis of tool wear and surface roughness in high-speed milling process of aluminum alloy Al6061

2021 ◽  
pp. 71-84
Author(s):  
Nhu-Tung Nguyen ◽  
Dung Hoang Tien ◽  
Nguyen Tien Tung ◽  
Nguyen Duc Luan
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Tool Wear ◽  
Feed Rate ◽  
High Speed ◽  
Cutting Speed ◽  
Milling Process ◽  
Face Milling ◽  
Depth Of Cut ◽  
High Speed Milling

In this study, the influence of cutting parameters and machining time on the tool wear and surface roughness was investigated in high-speed milling process of Al6061 using face carbide inserts. Taguchi experimental matrix (L9) was chosen to design and conduct the experimental research with three input parameters (feed rate, cutting speed, and axial depth of cut). Tool wear (VB) and surface roughness (Ra) after different machining strokes (after 10, 30, and 50 machining strokes) were selected as the output parameters. In almost cases of high-speed face milling process, the most significant factor that influenced on the tool wear was cutting speed (84.94 % after 10 machining strokes, 52.13 % after 30 machining strokes, and 68.58 % after 50 machining strokes), and the most significant factors that influenced on the surface roughness were depth of cut and feed rate (70.54 % after 10 machining strokes, 43.28 % after 30 machining strokes, and 30.97 % after 50 machining strokes for depth of cut. And 22.01 % after 10 machining strokes, 44.39 % after 30 machining strokes, and 66.58 % after 50 machining strokes for feed rate). Linear regression was the most suitable regression of VB and Ra with the determination coefficients (R2) from 88.00 % to 91.99 % for VB, and from 90.24 % to 96.84 % for Ra. These regression models were successfully verified by comparison between predicted and measured results of VB and Ra. Besides, the relationship of VB, Ra, and different machining strokes was also investigated and evaluated. Tool wear, surface roughness models, and their relationship that were found in this study can be used to improve the surface quality and reduce the tool wear in the high-speed face milling of aluminum alloy Al6061

scholarly journals Influence of the Cut Axial Depth on Surface Roughness at High-Speed Milling of Thin-Walled Workpieces

2021 ◽  
Vol 20 (2) ◽  
pp. 127-131
Author(s):  
A. I. Germashev ◽  
V. A. Logominov ◽  
S. I. Dyadya ◽  
Y. V. Kozlova ◽  
V. A. Krishtal
Keyword(s):  
High Speed ◽  
End Milling ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Work Piece ◽  
Natural Vibration Frequency ◽  
High Speed Milling ◽  
Wide Range ◽  
Thin Walled ◽  
Axial Depth

The paper presents the results of research on the dynamics of end milling of thin-walled work-pieces having complex geometric shapes. Since the milling process with shallow depths of cut is characterized by high intermittent cutting, the proportion of regenerative vibrations decreases, and the effect of forced vibrations on the dynamics of the process, on the contrary, increases. The influence of  axial depth of cut on the vibrations arising during processing, and roughness of the processed surface have been studied in paper.  The experiments have been carried out in a wide range of changes in the spindle speed at different axial cutting depths.  Vibrations of a thin-walled work-piece  have been recorded with an inductive sensor and recorded in digital form. Then an oscillogram has been used to estimate the amplitude and frequency of oscillations. The profilograms of the machined surface have been analysed. Roughness has been evaluated by the parameter Ra. The results have shown similar relationships for each of the investigated axial cutting depths. The worst cutting conditions  have been observed when the natural vibration frequency coincided with the tooth frequency or its harmonics. It is shown that the main cause of vibrations in high-speed milling  is forced rather than regenerative vibrations. Increasing the axial depth of cut at the same spindle speed increases the vibration amplitude. However, this does not significantly affect the roughness of the processed surface in cases when it comes to vibration-resistant processing.

Simulation of the High-Speed Milling Temperature of Titanium Alloy Ti - 6Al - 4V

2011 ◽  
Vol 314-316 ◽  
pp. 1171-1175 ◽  
Author(s):  
Xin Chun Huang ◽  
Chang Feng Yao ◽  
Ding Hua Zhang ◽  
Jun Xue Ren
Keyword(s):  
Titanium Alloy ◽  
Temperature Increase ◽  
High Speed ◽  
Milling Process ◽  
Cutting Depth ◽  
High Speed Milling ◽  
Element Simulation ◽  
Result Show ◽  
Milling Temperature ◽  
The Relationship

To study of the temperature generating mechanism of Titanium Alloy Ti - 6Al - 4V in high speed, and the influence rule of the milling process parameters for milling temperatures, A temperature simulation model of the milling process was found with AdvantEdge, the relationship between the high speed milling parameters and the milling temperature of Titanium Alloy Ti - 6Al - 4V was discussed by the finite element simulation, and the milling process temperature was measured by the half artificially thermocouple methods. The result show that the highest temperature are reached at close to the tool tip in the rack face, the feed per tooth have significant effect on the milling temperature, while cutting depth and milling width have little effect. The milling temperature increase with the feed per tooth increasing，the highest temperature increase with the spindle speed increasing.

Three-Dimensional Finite Element Analysis in Cutting Temperature for High Speed Milling of Titanium Alloys

2011 ◽  
Vol 189-193 ◽  
pp. 2259-2263
Author(s):  
You Xi Lin ◽  
Cong Ming Yan
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Titanium Alloys ◽  
High Speed ◽  
Three Dimensional ◽  
Cutting Temperature ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Radial Depth

A three dimensional fully thermal-mechanical coupled finite element model had been presented to simulate and analyze the cutting temperature for high speed milling of TiAl6V4 titanium alloy. The temperature distribution induced in the tool and the workpiece was predicted. The effects of the milling speed and radial depth of cut on the maximum cutting temperature in the tool was investigated. The results show that only a rising of temperature in the lamella of the machined surface is influenced by the milling heat. The maximum temperature in the tool increases with increasing radial depth of cut and milling speed which value is 310°C at a speed of 60 m/min and increases to 740°C at 400m/min. The maximum temperature is only effective on a concentrated area at the cutting edge and the location of the maximum temperature moves away from the tool tip for higher radial depths of milling. The predicted temperature distribution during the cutting process is consistent with the experimental results given in the literature. The results obtained from this study provide a fundamental understanding the process mechanics of HSM of titanium alloys.

Cutting Temperature in High Speed Milling of a Near Alpha Titanium Alloy

2006 ◽  
Vol 315-316 ◽  
pp. 145-149 ◽  
Author(s):  
Guo Sheng Geng ◽  
Jiu Hua Xu ◽  
Yu Can Fu ◽  
Y.F. Ge ◽  
C. Su
Keyword(s):  
Titanium Alloy ◽  
High Speed ◽  
Chemical Reactivity ◽  
Cutting Temperature ◽  
Cutting Parameters ◽  
Machining Accuracy ◽  
High Speed Milling ◽  
Thermocouple Method ◽  
Alpha Titanium ◽  
Cemented Carbide Tools

Cutting temperature has direct effects on tool wear and tool life, as well as machining accuracy and machining quality. Titanium alloys, however, are generally machined at lower cutting speeds with cemented carbide tools due to its low thermal conductivity and high chemical reactivity with cutting tool materials. This paper deals with cutting temperature in high-speed milling of a near alpha titanium alloy. The measuring principle of cutting temperature by the workpiece-constantan thermocouple method was illustrated and the physical meaning of the electromotive force (EMF) signals was described in the paper. The effects of cutting parameters and wear status on cutting temperature were studied, and the temperature distribution along the cutting edge was investigated.

Mechanics Modeling and Three-Dimensional Finite Element Simulating for High Speed Milling of Titanium Alloy

2010 ◽  
Vol 29-32 ◽  
pp. 360-364
Author(s):  
Yong Yang ◽  
Yu Ling Wang ◽  
Chang He Li
Keyword(s):  
Finite Element ◽  
Titanium Alloy ◽  
Finite Element Model ◽  
High Speed ◽  
Three Dimensional ◽  
Element Model ◽  
Milling Process ◽  
High Speed Milling ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

A three-dimensional finite element model of helix double-edge cutting is developed to study the ending milling process of titanium alloy Ti6Al4V. Several mechanics models of milling process, such as material constitutive model, friction model and heat transfer model, are implemented to improve finite element simulating accuracy. A milling force experiment is carried out, and a good agreement between simulation and experimental value is achieved, which proved that the finite element model presented in this paper is correct. Using this finite element model, chip formation and cutting temperature are simulated and analyzed. This work will be a base for process parameter optimization, tool’s optimization selection and design during high speed milling of difficult-to-cut titanium alloy.

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