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A 3-D Simulation and Experimental Study of Cutting Forces in Turning Inconel-718
Available online at www.sciencedirect.com
ScienceDirect Materials Today: Proceedings 4 (2017) 9942–9945
www.materialstoday.com/proceedings
ICEMS 2016
A 3-D Simulation and Experimental Study of Cutting Forces in Turning Inconel-718 Mechiri Sandeep Kumar*a, Rajashekhar Reddy Sa, V. Vasub a
Department of Mechanical Engineering, NIT Warangal, Telangana-506004
b
Assistant Professor, Department of Mechanical Engineering, NIT Warangal, Telangana-506004
Abstract Force measurement in metal cutting is an essential requirement as it is related to machine part design, tool design, power consumptions, vibrations, part accuracy, etc. It is the purpose of the measurement of cutting force to be able to understand the cutting mechanism such as the effects of cutting variables on the cutting force, the machinability of the work piece, the process of chip formation, chatter and tool wear. This paper presents a simulation model for estimation of cutting forces in turning process. A 3D simulation model was used for predicting the cutting forces as it is more nearer to practical process than the two dimensional model, although computing time is very large for a 3D model. A 3D model for oblique cutting is used and model to analyze turning of Inconel 718 using a TiAlN coated carbide inserts was developed using ABAQUS software. The finite element analysis incorporated the elastic and plastic properties of the work material in machining and Johnson-cook model is used for cutting simulation. The results from simulation model were compared with experimental data. A Taguchi’s L9 orthogonal array was used for the experimental runs. It is found that simulation results were in good agreement with experimental results. © 2017 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of International Conference on Recent Trends in Engineering and Material Sciences (ICEMS-2016). Keywords: Inconel-718, 3D simulation, Cutting forces
* Corresponding author. Tel.: +91-9966179582. E-mail address: [email protected]
2214-7853 © 2017 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of International Conference on Recent Trends in Engineering and Material Sciences (ICEMS2016).
M.S. Kumar et al. / Materials Today: Proceedings 4 (2017) 9942–9945
1.
9943
Introduction
Inconel 718 is a nickel based super alloy used in aerospace, chemical, automobile and marine applications because of its high strength to weight ratio, mechanical, thermal shock and fatigue and high corrosion resistance. Experimental method of obtaining data involves high cost and wastages; there is strong need for development of other approaches. Analytical and numerical methods are used to obtain data of cutting process. In simulation approach models can be modelled in two dimensional or three dimensional models. In two dimensional, orthogonal models can be modelled and in three dimensional both orthogonal and oblique cutting models can be modelled. Much of the literature on turning models is based on two dimensional approach because of computing time and complexity in three dimensional models [1]. But three dimensional simulation models are more nearer to the practical work. Martin Baker [2] developed a two dimensional orthogonal finite element model for the prediction of cutting forces in turning of titanium alloy with thermal softening. A three dimensional fem model which is capable of simulating a cutting operation was made by Ceretti et al. [3] with a Lagrangian approach. Orthogonal cutting operation is simulated. Chip formation is simulated and experimental and numerical cutting forces are compared. Yash R. Bhoyar et al.,[4] developed the FEA based models using DEFORM 3D that are able to predict the effect of various process variables on the interested performance measures like cutting forces, surface accuracy and breakages of tool. Ceretti et al. [5] developed a 3D turning model using DEFORM3D to evaluate machining forces, stress and temperature variations, together with chip flow, while orthogonal machining of aluminium alloy and also oblique machining of low-carbon steel. 2.
Materials and Models:
In these turning experiments and simulation models Inconel 718 alloy with 40mm diameter, 300mm length workpiece and TiAlN coated carbide inserts with ISO designation CNGG120408 are used. Turning experiments are carried out on a manual lathe machine with differential gear box by varying parameters such as speed (v), feed (f) and depth of cut (d) by using a L9 orthogonal array which is presented in the table. A highly sensitive six component Kristler type piezoelectric dynamometer 9257B model with a Multi-Channel Charge Amplifier is used to measure cutting forces online while experiments. After experiments workpiece is as shown in figure 1.
Figure.1. Work piece after turning
Figure.2. Simulation model
A three dimensional oblique turning simulation model is modeled using ABAQUS EXPLICIT module. Material properties [6] for Inconel 718 as follows: Density 8190 kg/m3, Young’s modulus 185Gpa, poisson ratio 0.33 and carbide tool as Density 1500 Kg/m3, young’s modulus 686Gpa and poisson ratio 0.22. Johnson cook flow stress [6, 7] model and ductile damage model is used and the values of J-C parameters are A, B, c, n and m as 1241MPa, 622MPa, 0.0134, 0.6522 and 1.3. The simulation model is used dynamic explicit procedure and meshed with an 8node linear brick with 0.5mm size. An assembly model of the simulation model is as shown in figure 2. Work piece modeled with rigid body constraints to get rotational motion. Johnson-cook model is suitable for modelling material
M.S. Kumar et al./ Materials Today: Proceedings 4 (2017) 9942–9945
9944
because high strain, strain rate, strain hardening and non-linear material properties are involved in turning process. It is defined in material library. 3.
Results: Table 1.L9 Orthogonal Array
S.No
Doc mm
Feed mm/rev
Speed m/min
1
0.5
0.082
80
Simulation 234
Cutting force, N Experimental 195
2 3 4
0.5
0.137
120
324
480
23.15%
0.5 1.0
0.178 0.082
160 120
398 372
398 269
21.11% 27.69%
5
1.0
0.137
160
473
550
15.86%
6
1.0
0.178
80
578
601
16.96%
7
1.5
0.082
160
462
358
22.51%
8
1.5
0.137
80
714
314
22.13%
9
1.5
0.178
120
812
249
25.99%
% Error 16.67%
CUTTING FORCE(N)
Cutting forces are influenced by speed, feed and depth of cut. By using an L9 orthogonal array effect of these parameters are observed on the cutting force with simulation model and validated with the experimental results. Both the actual experimental values and predicted values by simulation model are noted in the table. The percentage of error between the actual and simulation values are calculated and observed that the maximum error is 28%. experimental simulational
650 575 500 425 350 275 200 0.5
0.75 DOC (mm)
1
0.082
0.137
0.178
Feed (mm/rev)
80
120
160
Speed (m/min)
Figure.3. variation of Input Parameters
Variation of experimental and simulation results of cutting force with these parameters is as shown in figure. By regression analysis of L9 orthogonal array R2 value for experimentation is calculated as 0.9808 and for simulation work is 0.9841. These results show that the cutting forces decrease with cutting speed incrimination because material removal becomes easy with more heat generation at higher speeds. And cutting forces increase with the increase of depth of cut because of higher friction which obstacles the material removal and same with the case of higher feed rate. This phenomenon is same in case of the experimental values.
M.S. Kumar et al. / Materials Today: Proceedings 4 (2017) 9942–9945
9945
Table 2.Percentage contribution of input parameters
Parameter Doc Feed Speed Residual Total
Sum Of Squares Experimental Simulation 95532.67 178000 56706.6 87930.89 4540.67 7557.56 1908.67 4405.56 158700 278000
%Contribution Experimental Simulation 60.20% 64.03% 35.73% 31.63% 2.86% 2.72%
Percentage contributions of parameters for experimental and simulation models are calculated from ANOVA analysis of L9 orthogonal array and those are as noted in table 2. Effect of input parameters in simulation model is in good agreement with experimental values. Depth of cut is more dominant on cutting force than other two parameters and speed has less contribution on the cutting force in turning operation. 4.
Conclusions:
In this paper, 3D oblique turning process and Johnson cook flow stress model have been used to get the near possible simulation of the cutting forces during turning of Inconel 718. Cutting forces are mainly affected by depth of cut. Simulation results obtained from the ABAQUS oblique turning model are in good agreement with the experimental results. The variation in the cutting forces occurred because of practical limitations of vibrations, material properties and boundary conditions. From that we can conclude simulation models can be effectively useful in research studies for oblique turning process which can eliminate the wastages included in experimental work. We can select an appropriate cutting tool for the process without going for experimental work. References: [1] [2] [3] [4] [5] [6] [7]
Girinon Mathieu, Valiorgue Frederic, Robin Vincent, Feulvarch Eric., “3D stationary simulation of a turning operation with an Eulerian approach,” Applied Thermal Engineering, 2015, 134-146. Martin Baker., “Finite element simulation of high-speed cutting forces”, Journal of Materials Processing Technology 176 (2006) 117–126. E. Ceretti, C. Lazzaroni, L. Menegardo, T. Altan, Turning simulations using a three-dimensional FEM code, J. Mater. Process. Technology. 98 (1) (2000) 99e103. Yash R. Bhoyar, and P. D. Kamble., “Finite Element Analysis On Temperature Distribution In Turning Process Using DEFORM-3D,” IJRET: International Journal of Research in Engineering and Technology , Volume: 02, 2013,901-906 Ceretti, E., Lazzaroni, C., Menegardo, L. and Altan, T, “Turning simulations using a three-dimensional FEM code”, Journal of Materials Processing Technology (2010), Vol. 98, pp.99–103. T. Ozel , I. Llanos , J. Soriano & P.-J. Arrazol., “3d Finite Element Modelling Of Chip Formation Process For Machining Inconel 718: Comparison Of Fe Software Predictions,” Machining Science and Technology, 15:21–46 S.M. Afazov, S.M. Ratchev, J. Segal “Modelling and simulation of micro-milling cutting forces” Journal of Materials Processing Technology 210 (2010) 2154–2162.
ScienceDirect Materials Today: Proceedings 4 (2017) 9942–9945
www.materialstoday.com/proceedings
ICEMS 2016
A 3-D Simulation and Experimental Study of Cutting Forces in Turning Inconel-718 Mechiri Sandeep Kumar*a, Rajashekhar Reddy Sa, V. Vasub a
Department of Mechanical Engineering, NIT Warangal, Telangana-506004
b
Assistant Professor, Department of Mechanical Engineering, NIT Warangal, Telangana-506004
Abstract Force measurement in metal cutting is an essential requirement as it is related to machine part design, tool design, power consumptions, vibrations, part accuracy, etc. It is the purpose of the measurement of cutting force to be able to understand the cutting mechanism such as the effects of cutting variables on the cutting force, the machinability of the work piece, the process of chip formation, chatter and tool wear. This paper presents a simulation model for estimation of cutting forces in turning process. A 3D simulation model was used for predicting the cutting forces as it is more nearer to practical process than the two dimensional model, although computing time is very large for a 3D model. A 3D model for oblique cutting is used and model to analyze turning of Inconel 718 using a TiAlN coated carbide inserts was developed using ABAQUS software. The finite element analysis incorporated the elastic and plastic properties of the work material in machining and Johnson-cook model is used for cutting simulation. The results from simulation model were compared with experimental data. A Taguchi’s L9 orthogonal array was used for the experimental runs. It is found that simulation results were in good agreement with experimental results. © 2017 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of International Conference on Recent Trends in Engineering and Material Sciences (ICEMS-2016). Keywords: Inconel-718, 3D simulation, Cutting forces
* Corresponding author. Tel.: +91-9966179582. E-mail address: [email protected]
2214-7853 © 2017 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of International Conference on Recent Trends in Engineering and Material Sciences (ICEMS2016).
M.S. Kumar et al. / Materials Today: Proceedings 4 (2017) 9942–9945
1.
9943
Introduction
Inconel 718 is a nickel based super alloy used in aerospace, chemical, automobile and marine applications because of its high strength to weight ratio, mechanical, thermal shock and fatigue and high corrosion resistance. Experimental method of obtaining data involves high cost and wastages; there is strong need for development of other approaches. Analytical and numerical methods are used to obtain data of cutting process. In simulation approach models can be modelled in two dimensional or three dimensional models. In two dimensional, orthogonal models can be modelled and in three dimensional both orthogonal and oblique cutting models can be modelled. Much of the literature on turning models is based on two dimensional approach because of computing time and complexity in three dimensional models [1]. But three dimensional simulation models are more nearer to the practical work. Martin Baker [2] developed a two dimensional orthogonal finite element model for the prediction of cutting forces in turning of titanium alloy with thermal softening. A three dimensional fem model which is capable of simulating a cutting operation was made by Ceretti et al. [3] with a Lagrangian approach. Orthogonal cutting operation is simulated. Chip formation is simulated and experimental and numerical cutting forces are compared. Yash R. Bhoyar et al.,[4] developed the FEA based models using DEFORM 3D that are able to predict the effect of various process variables on the interested performance measures like cutting forces, surface accuracy and breakages of tool. Ceretti et al. [5] developed a 3D turning model using DEFORM3D to evaluate machining forces, stress and temperature variations, together with chip flow, while orthogonal machining of aluminium alloy and also oblique machining of low-carbon steel. 2.
Materials and Models:
In these turning experiments and simulation models Inconel 718 alloy with 40mm diameter, 300mm length workpiece and TiAlN coated carbide inserts with ISO designation CNGG120408 are used. Turning experiments are carried out on a manual lathe machine with differential gear box by varying parameters such as speed (v), feed (f) and depth of cut (d) by using a L9 orthogonal array which is presented in the table. A highly sensitive six component Kristler type piezoelectric dynamometer 9257B model with a Multi-Channel Charge Amplifier is used to measure cutting forces online while experiments. After experiments workpiece is as shown in figure 1.
Figure.1. Work piece after turning
Figure.2. Simulation model
A three dimensional oblique turning simulation model is modeled using ABAQUS EXPLICIT module. Material properties [6] for Inconel 718 as follows: Density 8190 kg/m3, Young’s modulus 185Gpa, poisson ratio 0.33 and carbide tool as Density 1500 Kg/m3, young’s modulus 686Gpa and poisson ratio 0.22. Johnson cook flow stress [6, 7] model and ductile damage model is used and the values of J-C parameters are A, B, c, n and m as 1241MPa, 622MPa, 0.0134, 0.6522 and 1.3. The simulation model is used dynamic explicit procedure and meshed with an 8node linear brick with 0.5mm size. An assembly model of the simulation model is as shown in figure 2. Work piece modeled with rigid body constraints to get rotational motion. Johnson-cook model is suitable for modelling material
M.S. Kumar et al./ Materials Today: Proceedings 4 (2017) 9942–9945
9944
because high strain, strain rate, strain hardening and non-linear material properties are involved in turning process. It is defined in material library. 3.
Results: Table 1.L9 Orthogonal Array
S.No
Doc mm
Feed mm/rev
Speed m/min
1
0.5
0.082
80
Simulation 234
Cutting force, N Experimental 195
2 3 4
0.5
0.137
120
324
480
23.15%
0.5 1.0
0.178 0.082
160 120
398 372
398 269
21.11% 27.69%
5
1.0
0.137
160
473
550
15.86%
6
1.0
0.178
80
578
601
16.96%
7
1.5
0.082
160
462
358
22.51%
8
1.5
0.137
80
714
314
22.13%
9
1.5
0.178
120
812
249
25.99%
% Error 16.67%
CUTTING FORCE(N)
Cutting forces are influenced by speed, feed and depth of cut. By using an L9 orthogonal array effect of these parameters are observed on the cutting force with simulation model and validated with the experimental results. Both the actual experimental values and predicted values by simulation model are noted in the table. The percentage of error between the actual and simulation values are calculated and observed that the maximum error is 28%. experimental simulational
650 575 500 425 350 275 200 0.5
0.75 DOC (mm)
1
0.082
0.137
0.178
Feed (mm/rev)
80
120
160
Speed (m/min)
Figure.3. variation of Input Parameters
Variation of experimental and simulation results of cutting force with these parameters is as shown in figure. By regression analysis of L9 orthogonal array R2 value for experimentation is calculated as 0.9808 and for simulation work is 0.9841. These results show that the cutting forces decrease with cutting speed incrimination because material removal becomes easy with more heat generation at higher speeds. And cutting forces increase with the increase of depth of cut because of higher friction which obstacles the material removal and same with the case of higher feed rate. This phenomenon is same in case of the experimental values.
M.S. Kumar et al. / Materials Today: Proceedings 4 (2017) 9942–9945
9945
Table 2.Percentage contribution of input parameters
Parameter Doc Feed Speed Residual Total
Sum Of Squares Experimental Simulation 95532.67 178000 56706.6 87930.89 4540.67 7557.56 1908.67 4405.56 158700 278000
%Contribution Experimental Simulation 60.20% 64.03% 35.73% 31.63% 2.86% 2.72%
Percentage contributions of parameters for experimental and simulation models are calculated from ANOVA analysis of L9 orthogonal array and those are as noted in table 2. Effect of input parameters in simulation model is in good agreement with experimental values. Depth of cut is more dominant on cutting force than other two parameters and speed has less contribution on the cutting force in turning operation. 4.
Conclusions:
In this paper, 3D oblique turning process and Johnson cook flow stress model have been used to get the near possible simulation of the cutting forces during turning of Inconel 718. Cutting forces are mainly affected by depth of cut. Simulation results obtained from the ABAQUS oblique turning model are in good agreement with the experimental results. The variation in the cutting forces occurred because of practical limitations of vibrations, material properties and boundary conditions. From that we can conclude simulation models can be effectively useful in research studies for oblique turning process which can eliminate the wastages included in experimental work. We can select an appropriate cutting tool for the process without going for experimental work. References: [1] [2] [3] [4] [5] [6] [7]
Girinon Mathieu, Valiorgue Frederic, Robin Vincent, Feulvarch Eric., “3D stationary simulation of a turning operation with an Eulerian approach,” Applied Thermal Engineering, 2015, 134-146. Martin Baker., “Finite element simulation of high-speed cutting forces”, Journal of Materials Processing Technology 176 (2006) 117–126. E. Ceretti, C. Lazzaroni, L. Menegardo, T. Altan, Turning simulations using a three-dimensional FEM code, J. Mater. Process. Technology. 98 (1) (2000) 99e103. Yash R. Bhoyar, and P. D. Kamble., “Finite Element Analysis On Temperature Distribution In Turning Process Using DEFORM-3D,” IJRET: International Journal of Research in Engineering and Technology , Volume: 02, 2013,901-906 Ceretti, E., Lazzaroni, C., Menegardo, L. and Altan, T, “Turning simulations using a three-dimensional FEM code”, Journal of Materials Processing Technology (2010), Vol. 98, pp.99–103. T. Ozel , I. Llanos , J. Soriano & P.-J. Arrazol., “3d Finite Element Modelling Of Chip Formation Process For Machining Inconel 718: Comparison Of Fe Software Predictions,” Machining Science and Technology, 15:21–46 S.M. Afazov, S.M. Ratchev, J. Segal “Modelling and simulation of micro-milling cutting forces” Journal of Materials Processing Technology 210 (2010) 2154–2162.