Finite element simulation and analysis of serrated chip formation during high–speed machining of AA7075–T651 alloy

2017 ◽  
Vol 26 ◽  
pp. 446-458 ◽  
Author(s):  
Walid Jomaa ◽  
Oussama Mechri ◽  
Julie Lévesque ◽  
Victor Songmene ◽  
Philippe Bocher ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Chip Formation ◽  
High Speed ◽  
High Speed Machining ◽  
Serrated Chip ◽  
Element Simulation ◽  
Serrated Chip Formation

The role of material model in the finite element simulation of high-speed machining of Ti6Al4V

2016 ◽  
Vol 230 (17) ◽  
pp. 2959-2967 ◽  
Author(s):  
Chong-Yang Gao ◽  
Liang-Chi Zhang ◽  
Peng-Hui Liu
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
High Speed ◽  
Material Model ◽  
Machining Process ◽  
High Speed Machining ◽  
Serrated Chip ◽  
Finite Element Program ◽  
Element Simulation ◽  
Improved Model

This paper provides a comprehensive assessment on some commonly used thermo-viscoplastic constitutive models of metallic materials during severe plastic deformation at high-strain rates. An hcp model previously established by us was improved in this paper to enhance its predictability by incorporating the key saturation characteristic of strain hardening. A compensation-based stress-updating algorithm was also developed to introduce the new hcp model into a finite element program. The improved model with the developed algorithm was then applied in finite element simulation to investigate the high-speed machining of Ti6Al4V. It was found that by using different material models, the simulated results of cutting forces, serrated chip morphologies, and residual stresses can be different too and that the improved model proposed in this paper can be applied to simulate the titanium alloy machining process more reliably due to its physical basis when compared with some other empirical Johnson–Cook models.

Finite Element Investigation of the Influence of Thermophysical Parameters on Segmented Chip Formation during High Speed Cutting

2011 ◽  
Vol 130-134 ◽  
pp. 2817-2821
Author(s):  
You Xi Lin ◽  
Cong Ming Yan
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Specific Heat ◽  
Chip Formation ◽  
High Speed ◽  
Element Model ◽  
Serrated Chip ◽  
High Speed Cutting ◽  
Thermophysical Parameters ◽  
Serrated Chip Formation

A 2D fully thermal mechanical coupled finite element model is applied to study the influence of material parameters on serrate chip formation during high speed cutting process. The serrated chip formation during high speed machining was predicted. Of interests are the effects of thermal conductivity, specific heat and density. Results showed significant influence of these thermophysical parameters on the serrated chip phenomena, especially in the case of the density. Increasing thermal conductivity specific heat and density lead to a decreasing degree of segmentation. The influence of the thermal conductivity on the cutting force and the specific heat on maximum temperatures in the shear band is also discussed.

Characteristics of serrated chip formation in high-speed machining of metallic materials

2016 ◽  
Vol 86 (5-8) ◽  
pp. 1201-1206 ◽  
Author(s):  
Qibiao Yang ◽  
Yin Wu ◽  
Dun Liu ◽  
Lie Chen ◽  
Deyuan Lou ◽  
...  
Keyword(s):  
Chip Formation ◽  
High Speed ◽  
High Speed Machining ◽  
Metallic Materials ◽  
Serrated Chip ◽  
Serrated Chip Formation

Serrated Chip Formation Induced Periodic Distribution of Morphological and Physical Characteristics in Machined Surface During High-Speed Machining of Ti6Al4V

2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Binbin Xu ◽  
Jun Zhang ◽  
Hongguang Liu ◽  
Xiang Xu ◽  
Wanhua Zhao
Keyword(s):  
Chip Formation ◽  
High Speed ◽  
High Speed Machining ◽  
Serrated Chip ◽  
Machined Surface ◽  
Periodic Distribution ◽  
Serrated Chip Formation ◽  
Simulation Results ◽  
Periodic Profile ◽  
Machined Surfaces

Abstract Difficult-to-cut materials are widely used in aerospace and other industries. Titanium alloys are the most popular ones among them due to their high strength-to-weight ratio and high temperature resistance. However, in high-speed machining, the alloys are prone to produce serrated chips, which have a serious influence on surface integrity. In this study, a coupled Eulerian–Lagrangian method is used to simulate the orthogonal cutting of Ti6Al4V due to its advantages of avoiding element distortion and improving the data extraction efficiency. The internal relationship between serrated chip formation and periodic profile of machined surfaces is analyzed by the simulation results and experimental data which are obtained by optical microscope and white light interferometer. Furthermore, thermal–mechanical loads on machined surfaces are reconstructed based on the simulation results, and a coupled finite element and cellular automata approach is used to describe the dynamic recrystallization process within the area of the machined surface during the formation of a single serration. According to the results, the periodic fluctuation of cutting forces is attributed to the serrated chip formation phenomenon, which then leads to the periodic profile of machined surfaces. The period is about 60–70 µm, and its amplitude decreases with the increase of cutting speeds. Moreover, the loads on machined surfaces also show the same period due to serrated chip formation. As a result, the grain refinement layer thickness (about 2 ∼ 5 µm) in machined surfaces is related to the surface temperature and exhibits the same periodic characteristics along the cutting direction.

Finite Element Simulation and Experiment of Chip Formation during High Speed Cutting of Hardened Steel

2010 ◽  
Vol 29-32 ◽  
pp. 1838-1843 ◽  
Author(s):  
Chun Zheng Duan ◽  
Hai Yang Yu ◽  
Yu Jun Cai ◽  
Yuan Yuan Li
Keyword(s):  
Finite Element ◽  
Cutting Force ◽  
High Speed ◽  
Chip Morphology ◽  
Hardened Steel ◽  
High Speed Machining ◽  
Serrated Chip ◽  
High Speed Cutting ◽  
Element Simulation ◽  
Aisi 1045

As an advanced manufacturing technology which has been developed rapidly in recent years, high speed machining is widely applied in many industries. The chip formation during high speed machining is a complicated material deformation and removing process. In research area of high speed machining, the prediction of chip morphology is a hot and difficult topic. A finite element method based on the software ABAOUS which involves Johnson-Cook material model and fracture criterion was used to simulate the serrated chip morphology and cutting force during high speed cutting of AISI 1045 hardened steel. The serrated chip morphology and cutting force were observed and measured by high speed cutting experiment of AISI 1045 hardened steel. The effects of rake angle on cutting force, sawtooth degree and space between sawteeth were discussed. The investigation indicates that the simulation results are consistent with the experiments and this finite element simulation method presented can be used to predict the chip morphology and cutting force accurately during high speed cutting of hardened steel.

Finite Element Simulation of High Speed Machining of Ti6Al4V Alloy and the Corresponding Experimental Study

2016 ◽  
Vol 836-837 ◽  
pp. 444-451 ◽  
Author(s):  
Long Hui Meng
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Finite Element Simulation ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Ti6al4v Alloy ◽  
Machining Process ◽  
High Speed Machining ◽  
Hopkinson Pressure Bar ◽  
Element Simulation

Finite element simulation of high speed machining of Ti6Al4V alloy was carried out based on the software of Abaqus. The Johnson-Cook constitutive model was chosen for the material of Ti6Al4V, the parameters of the model were obtained through the SHPB (Split Hopkinson Pressure Bar) experiment. The similarity of the chips obtained from the simulation and that obtained from the experiment indicated that the parameters of the Johnson-Cook constitutive model for Ti6Al4V alloy were reliable. Different cutting parameters and different tool geometric parameters were used in the simulations to find out their effects to the simulation results. Also a comparison was made between the results got form the simulations results and the experimental results, a good agreement between them indicated that the finite element simulation of high speed machining of Ti6Al4V is reliable, so it can be concluded that the finite element simulations of high speed machining can be widely used in practice to study the more about the machining process and reduce the experimental expenses.

Mechanism of Material Softening in Primary Shear Zone during Serrated Chip Formation in High Speed Machining of High Strength Steel

2009 ◽  
Vol 407-408 ◽  
pp. 504-508
Author(s):  
Chun Zheng Duan ◽  
Min Jie Wang ◽  
Yu Jun Cai
Keyword(s):  
Shear Zone ◽  
Chip Formation ◽  
High Speed ◽  
High Strength ◽  
Shear Zones ◽  
Adiabatic Shear ◽  
Microstructural Development ◽  
High Speed Machining ◽  
Serrated Chip ◽  
Serrated Chip Formation

The metallurgical observations of microstructure characteristics of the adiabatic shear bands(ASB) within the primary shear zones of the serrated chips produced during high speed machining high strength steel have been performed by using optical microscope, SEM and TEM. The observations showed that the microstructure between the matrix and the center of the ASB gradually was changed, the fine equiaxed grains appeared with size of about 0.4～0.6μm in the center of the adiabatic shear band. The serrated chip formation was likely due to material softening that occurred in the primary shear zones. The microstructural development of dynamic recovery and rotational dynamic recrystallization is the dominant metallurgical process leading to material softening in primary shear zone during high speed machining. A model of microstructural development in primary shear zone during serrated chip formation in high speed machining was suggested by analyzing material softening mechanism.

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