Analytical Modeling of Chip Geometry in High-Speed Ball-End Milling on Inclined Inconel-718 Workpieces

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Harshad A. Sonawane ◽  
Suhas S. Joshi
Keyword(s):  
High Speed ◽  
Cutting Tool ◽  
End Milling ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Shear Angle ◽  
Analytical Models ◽  
Ball End Milling ◽  
Cutting Mechanisms ◽  
Chip Geometry

Most often contoured surfaces inclined at several inclinations are generated using ball-end milling of aerospace and automobile components. It is understood that the chip morphology and the corresponding cutting mechanisms change with a change in the tool-workpiece interactions on inclined surfaces. Analytical predictive models to accurately evaluate the undeformed and deformed geometries of chip in ball-end milling are not available. Therefore, this work presents development of analytical models to predict the cutting tool-workpiece interaction as the workpiece inclination changes, in terms of undeformed and deformed chip cross sections. The models further evaluate instantaneous shear angle along any cross section of the tool-work interaction on a ball-end cutter in a milling operation. The models illustrate evaluation of a chip segment and mechanism of its formation in ball-end milling on an inclined work surface. It is observed that the chip dimensions, except deformed chip thickness, increase with an increase in the workpiece inclination angle. Also, a higher workpiece inclination results into an easy flow of the deformed chip over the cutting tool flank, which leads to a higher shear angle during the cut. The predictive chip geometry models corroborate 90% to the experimental results obtained at various workpiece inclinations.

Investigation on Chip Morphology and Surface Quality in High-Speed Ball-End Milling of Inconel 718

2010 ◽  
Vol 443 ◽  
pp. 353-358 ◽  
Author(s):  
Harshad A. Sonawane ◽  
Suhas S. Joshi
Keyword(s):  
Surface Quality ◽  
Inconel 718 ◽  
High Speed ◽  
End Milling ◽  
Chip Morphology ◽  
Helix Angle ◽  
Processing Parameters ◽  
Milling Process ◽  
Machining Parameters ◽  
Ball End Milling

The ball end milling process, commonly used for generating complex shapes, involves continuous variation in the uncut chip dimensions, which depends on the cutter geometry and the machining parameters. The proposed analytical model evaluates the undeformed and the deformed chip dimensions including chip length, width and thickness. The undeformed and deformed chip dimensions, is a function of cutter rotation angle, instantaneous cutter radius, helix angle, and other processing parameters. The surface quality, in the form of surface roughness, during high-speed ball end milling of Inconel 718 is also analysed in this paper.

Machinability Study Using Chip Thickness Ratio on Difficult to Cut Metals by CBN Cutting Tool

2012 ◽  
Vol 504-506 ◽  
pp. 1317-1322 ◽  
Author(s):  
Sivaprakasam Thamizhmanii ◽  
Hasan Sulaiman
Keyword(s):  
Stainless Steel ◽  
Cutting Force ◽  
High Speed ◽  
Cutting Tool ◽  
Cubic Boron Nitride ◽  
Chip Thickness ◽  
Shear Angle ◽  
Thickness Ratio ◽  
Depth Of Cut ◽  
Alloy Steels

Machinability is the one of the criteria in determining the life of the cutting tool. In this experiment, hard and difficult to cut materials like hard AISI 440 C stainless steel and hard SCM 440 alloy steels were discussed. However, machinability of the material is considered to be poor due to its inherent characteristics. The machinability studies on AISI 440 C stainless steel and SCM 440 alloy steels had not been carried out by researchers. Machinability indices used in such cases have the characteristics such as cutting force, surface roughness, tool wear etc. In the case of high-speed machining of said materials machinability indices such as chip thickness (RC), shear angle (Ф), surface integrity, and chip analysis are of prime importance. Most of the researchers have not given due consideration to these vital machinability indices necessary for understanding of high-speed cutting of said materials. In this work, an experimental investigation was carried out to understand the behavior of difficult to cut materials, when machined with Cubic Boron Nitride (CBN) insert tool. The results and analysis of this work indicated that the above-mentioned machinability indices are important and necessary to assess the machinability of said materials effectively. The operating parameters used were cutting velocity 100, 125, 150, 175 and 200 m/min with feed rate of 0.10, 0.20 and 0.30 mm rev-1 with constant depth of cut of 1.0 mm. The length of turning was 150 mm and 300 mm. Machinability of both materials and tool was evaluated in terms of roughness, flank wear, cutting force, chip thickness ratio and shear angle.

Cutting Thickness of High Speed Ball-End Milling Hardened Steel

2012 ◽  
Vol 426 ◽  
pp. 24-27
Author(s):  
Shu Cai Yang ◽  
Bin Jiang ◽  
H.Y. Li ◽  
M.L. Zheng ◽  
S.J. Wang
Keyword(s):  
High Speed ◽  
End Milling ◽  
Chip Thickness ◽  
Surface Damage ◽  
Transformation Process ◽  
Hardened Steel ◽  
Machined Surface ◽  
Element Analysis ◽  
Ball End Milling ◽  
Adiabatic Shearing

In order to solve the problem of machined surface damage and machining efficiency decline that caused by the decrease of effective cutting thickness in high speed ball-end milling hardened steel, using high speed cutting adiabatic shearing model, analyzed the adiabatic shearing deformation on hardened steel, and proposed the criterion of chip separating position. Analyzed the force in the transformation process from cutting to plowing, the influence of cutter deformation on cutting thickness was studied, and established the minimum cutting thickness model. Having done finite element analysis of cutter and experiment of high speed milling hardened steel, the validity of the minimum cutting thickness model was proved. The results show that cutting thickness changes from small to large, and then from large to small under the influence of cutting trajectory and tool edge radius. The deformation of cutter leads to the increase of the minimum cutting thickness, and further enhances chip thickness thinning effect. High feed can compensate cutting thickness thinning and the minimum cutting thickness model provides an effective way to restrain the damage of machined surface and cutter caused by cutter plowing.

Mechanistic Modeling of the Ball End Milling Process for Multi-Axis Machining of Free-Form Surfaces

2000 ◽  
Vol 123 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Rixin Zhu ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor
Keyword(s):  
End Milling ◽  
Chip Thickness ◽  
Mechanistic Modeling ◽  
Free Form ◽  
Surface Geometry ◽  
Workpiece Surface ◽  
Ball End Milling ◽  
Modeling Approach ◽  
Free Form Surfaces ◽  
Cutting Point

A mechanistic modeling approach to predicting cutting forces is developed for multi-axis ball end milling of free-form surfaces. The workpiece surface is represented by discretized point vectors. The modeling approach employs the cutting edge profile in either analytical or measured form. The engaged cut geometry is determined by classification of the elemental cutting point positions with respect to the workpiece surface. The chip load model determines the undeformed chip thickness distribution along the cutting edges with consideration of various process faults. Given a 5-axis tool path in a cutter location file, shape driving profiles are generated and piecewise ruled surfaces are used to construct the tool swept envelope. The tool swept envelope is then used to update the workpiece surface geometry employing the Z-map method. A series of 3-axis and 5-axis surface machining tests on Ti6A14V were conducted to validate the model. The model shows good computational efficiency, and the force predictions are found in good agreement with the measured data.

scholarly journals Experimental Verification of Chatter-Free Ball End Milling Strategy

2013 ◽  
Vol 7 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Lin Lu ◽  
◽  
Masahiko Sato ◽  
Hisataka Tanaka ◽  
Keyword(s):  
Cutting Tool ◽  
End Milling ◽  
Cutting Parameters ◽  
Cutting Condition ◽  
Chatter Stability ◽  
Chatter Vibration ◽  
Ball End Milling ◽  
Machining Center ◽  
Avoidance Control ◽  
Avoidance Strategy

Chatter vibration frequently occurs in ball end milling. If the characteristics of the cutting tool system and cutting process are known, chatter stability in ball end milling can be evaluated. Hence, in this paper, a chatter-avoidance strategy based on a regenerative chatter theory is proposed to prevent the occurrence of chatter. This consists of a simulation of chatter stability and cutting condition control. When the characteristics of a vibration system change, this chatter-avoidance strategy cannot cope with it. Therefore, another chatter-avoidance control algorism that changes cutting parameters on a machining center is proposed. This can adapt to the change in the characteristics of the vibration systemduring cutting. The effectiveness of the two chatter-avoidance methods proposed is examined through experiments.

Experimental Investigation of the Effect of the Machine Kinematic Behavior on the Surface Topography and Roughness in High Speed Ball end Milling of the AISI4142 Steel

2021 ◽  
Author(s):  
Sai Lotfi ◽  
Belguith Rami ◽  
Baili Maher ◽  
Desseins Gilles ◽  
Bouzid Wassila
Keyword(s):  
Surface Topography ◽  
High Speed ◽  
End Milling ◽  
Experimental Investigations ◽  
Ball End Milling ◽  
Tool Paths ◽  
Stationary Zone ◽  
Machining Errors ◽  
Kinematic Behavior ◽  
Milling Tool

Abstract The analysis of the surface topography in ball end milling is an objective studied by many researchers, several methods were used and many combinations of cutting conditions and machining errors are considered. In the milling tool paths the trajectories presents a points of changing direction where the tool decelerates before and accelerates after respecting the velocity profiles of the machine. In this paper, we propose experimental investigations of the effect of the kinematic behavior of the machine tool on the surface quality. A poor topography and roughness are remarked on the deceleration and the acceleration zones compared to the stationary zone.

Analytical Prediction of Stability Lobes in Ball End Milling

1999 ◽  
Vol 121 (4) ◽  
pp. 586-592 ◽  
Author(s):  
Y. Altıntas¸ ◽  
E. Shamoto ◽  
P. Lee ◽  
E. Budak
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Transformation Method ◽  
Quadratic Equation ◽  
Analytical Prediction ◽  
Force Coefficient ◽  
Ball End Milling ◽  
Stability Lobes

The paper presents an analytical method to predict stability lobes in ball end milling. Analytical expressions are based on the dynamics of ball end milling with regeneration in the uncut chip thickness, time varying directional factors and the interaction with the machine tool structure. The cutting force coefficients are derived from orthogonal cutting data base using oblique transformation method. The influence of cutting coefficients on the stability is investigated. A computationally efficient, an equivalent average cutting force coefficient method is developed for ball end milling. The prediction of stability lobes for ball end milling is reduced to the solution of a simple quadratic equation. The analytical results agree well with the experiments and the computationally expensive and complex numerical time domain simulations.

Forces and Chip Morphology of Nickel-Based Superalloy Inconel 718 during High Speed Grinding with Single Grain

2013 ◽  
Vol 589-590 ◽  
pp. 209-214 ◽  
Author(s):  
Jia Yan Zhao ◽  
Yu Can Fu ◽  
Jiu Hua Xu ◽  
Lin Tian ◽  
Lu Yang
Keyword(s):  
Inconel 718 ◽  
High Speed ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Groove Surface ◽  
Nickel Based Superalloy ◽  
High Speed Grinding ◽  
Grinding Mechanism ◽  
Single Grain ◽  
Diamond Grain

Single-grain grinding test plays an important part in studying the high speed grinding mechanism of materials. In this paper, a new experimental system for high speed grinding test with single diamond grain is presented. The differences of surface topography and chip morphology of Inconel 718 machined by single diamond grain and single CBN grain were evaluated. The grinding forces and corresponding maximum undeformed chip thickness were measured under different grinding speeds. The chips, characterized by crack and segment band feature like the cutting segmented chips, were collected to study the high speed grinding mechanism of nickel-based superalloy. The results show that the grinding speed has an important effect on the forces and chip formation, partly due to the temperature variation. As the speed increases, the groove surface becomes smoother.

Tool Path Generation Method of Equal Approximation Error for Free-Form Surface in High Speed Machining

2010 ◽  
Vol 102-104 ◽  
pp. 544-549 ◽  
Author(s):  
Chun Jiang Zhou ◽  
Hong Chun Chen
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cutting Tool ◽  
End Milling ◽  
Approximation Error ◽  
Tool Path Generation ◽  
Free Form ◽  
Path Generation ◽  
High Speed Machining ◽  
Free Form Surface

The development of surface high-speed machining has put forward higher demands for uniform cutting load and smooth cutting tool path. Most current tool-path planning methods are based on constant scallop height, but they have the disadvantage of path point redundancy during the path discretization process. To overcome the problem, a tool path generation method of equal approximation error in each step for free-form surface is presented based on geodesic principle and curvature judgment. In this method, the NURBS curve is employed to realize smooth transition for adjacent two tool paths in high-speed machining. A certain angle of inclination of flat-end milling cutter during multi-axis machining improves the machining efficiency. Because of the advantage of this machining condition, the cutter location point generation algorithm during the machining condition is given by the method. The method is verified and simulated by C++. Experiment results proved that it can obtain uniform cutting load and continuous smooth cutting tool path during surface high-speed machining by the proposed method.

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