scholarly journals Machinability analysis of dry and liquid nitrogen–based cryogenic cutting of Inconel 718: experimental and FE analysis

Author(s):  
Salman Pervaiz ◽  
Sathish Kannan ◽  
Saqib Anwar ◽  
Dehong Huo

Abstract Inconel 718 is famous for its applications in the aerospace industry due to its inherent properties of corrosion resistance, wear resistance, high creep strength, and high hot hardness. Despite the favorable properties, it has poor machinability due to low thermal conductivity and high hot hardness. To limit the influence of high cutting temperature in the cutting zone, application of cutting flood is recommended during the cutting operation. Cryogenic cooling is the recommended method when machining Inconel 718. However, there is very limited literature available when it comes to the numerical finite element modeling of the process. This current study is focused on the machinability analysis of Inconel 718 using numerical approach with experimental validations. Dry and cryogenic cooling methods were compared in terms of associated parameters such as chip compression ratio, shear angle, contact length, cutting forces, and energy consumption for the primary and secondary deformation zones. In addition, parameters related to chip morphology were also investigated under both lubrication methods. Chip formation in cryogenic machining was well captured by the finite element assisted model and found in good agreement with the experimental chip morphology. Both experimental and numerical observations revealed comparatively less chip compression ratio in the cryogenic cooling with larger value of shear plane angle. This results in the smaller tool–chip contact length and better comparative lubrication.

2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Muralimohan Gurusamy ◽  
Karthik Palaniappan ◽  
H. Murthy ◽  
Balkrishna C. Rao

Abstract The objective of this work is to study the performance of modified Zerilli–Armstrong constitutive relation proposed in our previous study for the finite element modeling of a severe plastic deformation technique called large strain extrusion machining. The modified Zerilli–Armstrong constitutive relation is implemented in a finite element model of large strain extrusion machining of Inconel 718 to analyze the influence of process parameters, i.e., the chip compression ratio and tool–chip friction, on deformation, effective strain distribution, and hydrostatic pressure distribution along the extruded chip. The predicted strain values for different chip compression ratios were validated by comparison with those obtained through an analytical model. The finite element predictions also served as a guideline in designing the large strain extrusion-machining setup on which experiments were conducted to generate Inconel 718 foils with superior mechanical properties. The predicted limits of chip compression ratio were in close agreement with experimentally realizable values. Furthermore, the predicted strain distribution through the thickness of the chip was validated with the results of hardness measurement tests. Microstructural characterization of the Inconel 718 foils was carried out by using both optical and transmission-electron microscopic studies in order to reveal the presence of fine-grain structures. The validations showed the effectiveness of the modified Zerilli–Armstrong constitutive relation in modeling large strain extrusion machining—a variant of the conventional machining process.


Author(s):  
Xiangqin Zhang ◽  
Xueping Zhang ◽  
A. K. Srivastava

To predict the cutting forces and cutting temperatures accurately in high speed dry cutting Ti-6Al-4V alloy, a Finite Element (FE) model is established based on ABAQUS. The tool-chip-work friction coefficients are calculated analytically using the measured cutting forces and chip morphology parameter obtained by conducting the orthogonal (2-D) machining tests. It reveals that the friction coefficients between tool-work are 3∼7 times larger than that between tool-chip, and the friction coefficients of tool-chip-work vary with feed rates. The analysis provides a better reference for the tool-work-chip friction coefficients than that given by literature empirically regardless of machining conditions. The FE model is capable of effectively simulating the high speed dry cutting process of Ti-6Al-4V alloy based on the modified Johnson-Cook model and tool-work-chip friction coefficients obtained analytically. The FE model is further validated in terms of predicted forces and the chip morphology. The predicted cutting force, thrust force and resultant force by the FE model agree well with the experimentally measured forces. The errors in terms of the predicted average value of chip pitch and the distance between chip valley and chip peak are smaller. The FE model further predicts the cutting temperature and residual stresses during high speed dry cutting of Ti-6Al-4V alloy. The maximum tool temperatures exist along the round tool edge, and the residual stress profiles along the machined surface are hook-shaped regardless of machining conditions.


2015 ◽  
Vol 77 (27) ◽  
Author(s):  
A. H. Musfirah ◽  
J. A. Ghani ◽  
C. H. Che Haron ◽  
M. S. Kasim

In tribology phenomenon, surface roughness has become one of the most important factors that contributed to the evaluation of part quality during machining operation. In order to understand the behavior of cryogenic cooling assistance in machining Inconel 718, this paper aims to provide better understanding of tribological characterization of liquid nitrogen near the cutting zone of this material in ball end milling process. Experiments were performed using a multi-layer TiAlN/AlCrN-coated carbide inserts under cryogenic and dry cutting condition. A transient milling simulation model using Third Wave Advantedge has been done in order to gain in-depth understanding of the thermomechanical aspects of machining and their influence on resulted part quality. The cryogenic results of the cutting temperature, cutting forces and surface roughness of the ball nose cutting tool have been compared with those of dry machining. Finally, experimental results proved that cryogenic implementation can  decrease the amount of heat transferred to the tool up to almost 70% and improve the surface roughness to a maximum of 31% when compared with dry machining. Furthermore, the microstructure of machined workpiece revealed that cryogenic cooling also can reduce a plastic deformation at the cutting surface as compared with the dry machining. 


2018 ◽  
Vol 30 ◽  
pp. 1-7 ◽  
Author(s):  
Fatih Hayati Çakır ◽  
Mehmet Alper Sofuoğlu ◽  
Selim Gürgen

Nickel-based alloys provide high corrosion resistance and high-temperature strength but these alloys possess poor machinability. Hastelloy-X is a nickel based alloy that has been used for high temperature use. There are many studies about finite element modeling of aerospace alloys but studies in literature with Hastelloy-X are limited. In the present work, machining characteristics of Hastelloy-X were investigated and a numerical model was developed for the turning operation of Hastelloy-X. Two input parameters (cutting speed and feed rate) were variated in the operations and the results were evaluated considering process outputs such as cutting forces, cutting temperature, effective stresses and chip morphology. Based on the verification of the numerical model using experimental results, presented material model is appropriate for the turning operation of Hastelloy-X at low and medium cutting speed machining conditions.


Author(s):  
Walid Jomaa ◽  
Monzer Daoud ◽  
Victor Songmene ◽  
Philippe Bocher ◽  
Jean-François Châtelain

This study aims to identify the coefficients of Marusich’s constitutive equation (MCE) for the aluminum AA7075-T651. Material constants were identified inversely form orthogonal machining tests and from dynamic tests. The proposed material model was successfully implemented in a finite element model (FEM) to simulate the high speed machining of the aluminum AA7075-T6. Deform 2D® software was used. A reasonable agreement between predictions and experiments was obtained. The comparison was based on cutting forces, chip morphology, and tool/chip contact length.


2011 ◽  
Vol 239-242 ◽  
pp. 801-805 ◽  
Author(s):  
De Wen Tang ◽  
Ru Shu Peng ◽  
Rui Lan Zhao

According to the weak rigidity characteristics of thin-walled parts, the material parameters and deformation tools are taken into account. In this paper, the finite element model of high-speed milling process is systematically studied by a large-scale finite element analysis (FEA) software DEFORM-3D with the modified Johnson-Cook model. The simulated results of cutting force, chip morphology, effective stress, effective strain and cutting temperature in deformation zones of thin-wall part are analyzed. On the basis of simulation results, cutting force of high speed milling on thin-wall part is verified. Comparing to the experimental results, the simulated results of cutting force, chip morphology, effective stress and cutting temperature in deformation zones of high speed peripheral milling indicate good consistence and the models established can be used to accurately predict the thin wall deformation. Therefore, numerical simulation method for the thin wall milling deformation control and provide a new way of compensation.


Author(s):  
Sunil Dutta ◽  
Suresh Kumar Reddy Narala

Finite element analysis has become an indispensable tool, often used in research and development, to provide valuable insights into the process. The studies in the metal cutting area mostly employ the Finite element method (FEM) due to its ability to highlight the physics involved in chip formation and the range of force generated in the cutting zone. The study involves investigations by adopting the Johnson-Cook (JC) constitutive model with energy-based damage criteria to simulate the turning of a fabricated AM (Mg alloy: 7 wt%Al-0.9 wt%Mn) alloy. For the FEM, the JC and Damage model constants are calculated using inverse identification methodology. The results obtained on the cutting force (Fc), cutting temperature (Tc), and chip-thickness (tc) at different combinations of turning parameters were analyzed and compared with the experimental values. The Predicted data was in line with the experimental data, and a variation of mostly less than 12% was observed. Thus, establishing the efficacy of inverse identification method. Further, the obtained results exhibit the significant influence of turning parameters on Fc(N), Tc(°C), and tc(mm) and enunciates crucial facts related to the AM alloy's machinability.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4142
Author(s):  
Zhongfei Zou ◽  
Lin He ◽  
Hongwan Jiang ◽  
Sen Yuan ◽  
Zhongwei Ren

This study designed a new microgroove cutting tool to machine Inconel 718 and focused on the effect of microgroove structure on the cutting performance and chip morphology during the turning. A comparative analysis of the cutting force, cutting temperature, tool life, tool wear, and chip morphology of the microgroove cutting tool and the original cutting tool was conducted. The main cutting force and temperature of the microgroove cutting tool were reduced by 12% and 12.17%, respectively, compared with the original cutting tool. The microgroove cutting tool exhibited a significant improvement compared with the original cutting tool, which extended the tool life by up to 23.08%. Further, the microgroove cutting tool distorted the curl radius of the chips extensively. The experimental results showed that the microgroove structure can not only improve the tool life, but also improve the chip breaking effect.


2010 ◽  
Vol 443 ◽  
pp. 274-278 ◽  
Author(s):  
De Weng Tang ◽  
Cheng Yong Wang ◽  
Ying Ning Hu ◽  
Yue Xian Song

The modeling and simulation of chip formation during high speed milling of hardened mold steel are systematically studied by the Finite Element Analysis (FEA). The modified Johnson-Cook’s constitutive equation for hardened mold steel is introduced. Comparing to the experimental results, the simulated results of cutting force, chip morphology, effective stress and cutting temperature in deformation zones of high speed peripheral milling indicate good consistence and the models established can be used to accurately predict the behavior of hardened mold steel.


2014 ◽  
Vol 1017 ◽  
pp. 399-405 ◽  
Author(s):  
Lin Jiang He ◽  
Hong Hua Su ◽  
Jiu Hua Xu ◽  
Jia Bao Fu

Nickel-based alloy is known as one of the most difficult–to-machine materials and the milling process is one of the most common metal removal operations. Modeling and simulation of milling process have the potential for understanding the milling mechanism, improving cutting tool designs and selecting optimum conditions, especially in advanced applications such as high-speed milling. This paper presents a 3D coupled thermo-mechanical finite element model based on ABAQUS\Explicit for the simulation of Inconel 718 chip formation in metal cutting. In the simulations, a Lagrangian formulation with an explicit solution scheme and a penalty contact algorithm has been used. The material behavior is modeled with classical Johnson-cook plasticity constitutive model and dynamic failure criteria for element removal, coupled with adaptive meshing and mass scaling technology for limiting the calculation time. The milling tool is modeled in UG software according to the real tool geometry, and meshed as a rigid tool. In order to verify the accuracy of 3D simulation, results (cutting forces and cutting temperature) were compared with the experimental results under the same cutting conditions as the simulations. The results obtained indicate that the simulation methodology is capable of predicting the cutting forces and cutting temperature. It suggests that 3D finite element simulation model of cutting processes can be truly trusted.


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