scholarly journals Shoulder Damage Model and Its Application for Single Point Diamond Machining of ZnSe Crystal

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 233
Author(s):  
Shenxin Yin ◽  
Huapan Xiao ◽  
Wenjun Kang ◽  
Heng Wu ◽  
Rongguang Liang
Keyword(s):  
Single Point ◽  
Orthogonal Cutting ◽  
Damage Model ◽  
Chip Thickness ◽  
Processing Parameters ◽  
Znse Crystal ◽  
Spring Back ◽  
Diamond Machining ◽  
Brittle Ductile Transition ◽  
Damage Depth

The damaging of ZnSe crystal has a significant impact on its service performance and life. Based on the specific cutting energies for brittle and ductile mode machining, a model is proposed to evaluate the damage depth in the shoulder region of ZnSe crystal during single point diamond machining. The model considers the brittle-ductile transition and spring back of ZnSe crystal. To verify the model, the elastic modulus, hardness, spring back, and friction coefficient of ZnSe crystal are measured by nanoindentation and nanoscratch tests, and its critical undeformed chip thickness is obtained by spiral scratching. Meanwhile, orthogonal cutting experiments are conducted to obtain the different shoulder regions and cutting surfaces. The shoulder damage depth is analyzed, indicating that the effect of the feed on the damage depth at a high cutting depth is stronger than that at a low one. The model is verified to be effective with an average relative error of less than 7%. Then, the model is used to calculate the critical processing parameters and achieve a smooth ZnSe surface with a roughness Sa = 1.0 nm. The model is also extended to efficiently predict the bound of the subsurface damage depth of a cutting surface. The research would be useful for the evaluation of surface and subsurface damages during the ultra-precision machining of ZnSe crystal.

scholarly journals One-Side Cutting Strategy for Ultraprecise Single Point Cutting of V-grooves Case 1: Constant Chip Thickness

2019 ◽  
Vol 52 (10) ◽  
pp. 306-310
Author(s):  
Delfim Joao ◽  
Nicolas Milliken ◽  
O. Remus Tutunea-Fatan ◽  
Evgueni V. Bordatchev
Keyword(s):  
Single Point ◽  
Chip Thickness ◽  
Cutting Strategy

New Thermal Issues on the Modelling of Tool-Workpiece Interaction: Application to Dry Cutting of AISI 1045 Steel

2011 ◽  
Vol 223 ◽  
pp. 286-295 ◽  
Author(s):  
Cédric Courbon ◽  
Tarek Mabrouki ◽  
Joël Rech ◽  
Denis Mazuyer ◽  
Enrico D'Eramo
Keyword(s):  
Heat Flux ◽  
Hot Spot ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Contact Length ◽  
Dry Cutting ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
1045 Steel ◽  
Coated Carbide

The present work proposes to enhance the thermal interface denition in Finite Element (FE) simulations of machining. A user subroutine has been developed in Abaqus/Explicit © to implement a new experimentally-based heat partition model extracted from tribological tests. A 2D Arbitrary-Lagragian-Eulerian (ALE) approach is employed to simulate dry orthogonal cutting of AISI 1045 steel with coated carbide inserts. Simulation results are compared to experimental ones over a whole range of cutting speeds and feed rates in terms of average cutting forces, chip thickness, tool chip contact length and heat flux. This study emphasizes that heat transfer and temperature distribution in the cutting tool are drastically in uenced by the thermal formulation used at the interface. Consistency of the numerical results such as heat flux transmitted to the tool, peak temperature as well as hot spot location can be denitively improved.

scholarly journals Analytical modelling of cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V

2014 ◽  
Vol 229 (6) ◽  
pp. 1122-1133 ◽  
Author(s):  
Yun Chen ◽  
Huaizhong Li ◽  
Jun Wang
Keyword(s):  
Titanium Alloy ◽  
Cutting Forces ◽  
Chemical Reactivity ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Analytical Modelling ◽  
Shear Instability ◽  
Published Data ◽  
Machining Processes ◽  
Titanium Alloy Ti6al4v

Titanium and its alloys are difficult to machine due to their high chemical reactivity with tool materials and low thermal conductivity. Chip segmentation caused by the thermoplastic instability is always observed in titanium machining processes, which leads to varied cutting forces and chip thickness, etc. This paper presents an analytical modelling approach for cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V. The catastrophic shear instability in the primary shear plane is assumed as a semi-static process. An analytical approach is used to evaluate chip thicknesses and forces in the near-orthogonal cutting process. The shear flow stress of the material is modelled by using the Johnson–Cook constitutive material law where the strain hardening, strain rate sensitivity and thermal softening behaviours are coupled. The thermal equations with non-uniform heat partitions along the tool–chip interface are solved by a finite difference method. The model prediction is verified with experimental data, where a good agreement in terms of the average cutting forces and chip thickness is shown. A comparison of the predicted temperatures with published data obtained by using the finite element method is also presented.

FE analysis of the effects of process representations on the prediction of residual stresses and chip morphology in the down-milling of Ti6Al4V

2021 ◽  
pp. 1-50
Author(s):  
Nejah Tounsi ◽  
Tahany El-Wardany
Keyword(s):  
Experimental Data ◽  
Residual Stresses ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Milling Process ◽  
Uncut Chip Thickness ◽  
Orthogonal Machining ◽  
Cutting Length ◽  
Sequential Cuts

Abstract Part I of these two-part papers will investigate the effect of three FEM representations of the milling process on the prediction of chip morphology and residual stresses (RS), when down-milling small uncut chips with thickness in the micrometer range and finite cutting edge radius. They are: i) orthogonal cutting with the mean uncut chip thickness t, obtained by averaging the uncut chip thickness over the cutting length, ii) orthogonal cutting with variable t, which characterizes the down-milling process and which is imposed on a flat surface of the final workpiece, and iii) modelling the true kinematics of the down milling process. The appropriate constitutive model is identified through 2D FEM investigation of the effects of selected constitutive equations and failure models on the prediction of RS and chip morphology in the dry orthogonal machining of Ti6Al4V and comparison to experimental measurements. The chip morphology and RS prediction capability of these representations is assessed using the available set of experimental data. Models featuring variable chip thickness have revealed the transition from continuous chip formation to the rubbing mode and have improved the predictions of residual stresses. The use of sequential cuts is necessary to converge toward experimental data.

scholarly journals Machining-Induced Work Hardening Behavior of Inconel 718 Considering Edge Geometries

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 397
Author(s):  
Bin Zhou ◽  
Weiwei Zhang ◽  
Zhongmei Gao ◽  
Guoqiang Luo
Keyword(s):  
Grain Size ◽  
Work Hardening ◽  
Inconel 718 ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Machined Surface ◽  
Work Hardening Behavior ◽  
Hardening Behavior ◽  
Significant Difference ◽  
Optimization Of Cutting Parameters

As a representative type of superalloy, Inconel 718 is widely employed in aerospace, marine and nuclear industries. The significant work hardening behavior of Inconel 718 can improve the service performance of components; nevertheless, it cause extreme difficulty in machining. This paper aims to investigate the influence of chamfered edge parameters on work hardening in orthogonal cutting of Inconel 718 based on a novel hybrid method, which integrates Coupled Eulerian-Lagrangian (CEL) method and grain-size-based functions considering the influence of grain size on microhardness. Orthogonal cutting experiments and nanoindentation tests are conducted to validate the effectiveness of the proposed method. The predicted results are highly consistent with the experimental results. The depth of work hardening layer increases with increasing chamfer angle and chamfer width, also with increasing feed rate (the uncut chip thickness). However, the maximum microhardness on the machined surface does not exhibit a significant difference. The proposed method can provide theoretical guidance for the optimization of cutting parameters and improvement of the work hardening.

Effect of Minimum Quantity Lubrication to Prediction of Cutting Temperature Distribution in Turning Material AISI-1045

2020 ◽  
Vol 902 ◽  
pp. 97-102
Author(s):  
Tran Trong Quyet ◽  
Pham Tuan Nghia ◽  
Nguyen Thanh Toan ◽  
Tran Duc Trong ◽  
Luong Hong Sam ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Shear Zone ◽  
Orthogonal Cutting ◽  
Cutting Temperature ◽  
Chip Thickness ◽  
Minimum Quantity Lubrication ◽  
Minimum Quantity ◽  
The Difference ◽  
Secondary Shear Zone ◽  
Cutting Model

This paper presents a prediction of cutting temperature in turning process, using a continuous cutting model of Johnson-Cook (J-C). An method to predict the temperature distribution in orthogonal cutting is based on the constituent model of various material and the mechanics of their cutting process. In this method, the average temperature at the primary shear zone (PSZ) and the secondary shear zone (SSZ) were determined for various materials, based on a constitutive model and a chip-formation model using measurements of cutting force and chip thicknes. The J-C model constants were taken from Hopkinson pressure bar tests. Cutting conditions, cutting forces and chip thickness were used to predict shear stress. Experimental cutting heat results with the same cutting parameters using the minimum lubrication method (MQL) were recorded through the Testo-871 thermal camera. The thermal distribution results between the two methods has a difference in value, as well as distribution. From the difference, we have analyzed some of the causes, finding the effect of the minimum quantity lubrication parameters on the difference.

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.

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