Optimization of Tensile Residual Stress on Machined Surface in MQL Turning

2015 ◽  
Vol 713-715 ◽  
pp. 209-212 ◽  
Author(s):  
Xia Ji ◽  
Alexander H. Shih ◽  
Manik Rajora ◽  
Ya Min Shao ◽  
Steven Y. Liang
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Minimum Quantity Lubrication ◽  
Optimization Procedure ◽  
Stress Generation ◽  
Tool Geometry ◽  
Machined Surface ◽  
Good Surface ◽  
Optimal Inputs ◽  
Marquardt Algorithm

Producing good surface integrity is one of the main challenges of the machining industry. The increase of the utilization of minimum quantity lubrication (MQL) in order to reduce the amount of lubrication induced a lack of understanding of the physics behind the residual stress generation. Residual stress in the machined surface and subsurface is affected by materials, machining conditions, and tool geometry. These residual stresses could affect the service qualify and component life significantly. Residual stress can be determined by empirical or numerical experiments for selected configurations, even if both are expensive procedures. This paper presents a hybrid neural network that is trained using Simulated Annealing (SA) and Levenberg-Marquardt Algorithm (LM) in order to predict the values of residual stresses in cutting and radial direction after the MQL face turning process accurately. First, SA is used to train the weight and bias values of the ANN after which LM is used to fine tune the values trained by SA. Then, based on the predictions, an optimization procedure, using Genetic Algorithm (GA), is applied in order to find the best cutting conditions. At each generation, GA suggests a population of inputs that are then sent to the trained ANN in order to predict the residual stresses. The objective is to find the optimal inputs that minimize the tensile stress on the machined surface.

A Hybrid Neural Network for Prediction of Surface Residual Stress in MQL Face Turning

2014 ◽  
Vol 633-634 ◽  
pp. 574-578 ◽  
Author(s):  
Xia Ji ◽  
Alexander H. Shih ◽  
Manik Rajora ◽  
Ya Min Shao ◽  
Steven Y. Liang
Keyword(s):  
Neural Network ◽  
Residual Stress ◽  
Residual Stresses ◽  
Surface Integrity ◽  
Tool Geometry ◽  
Surface Residual Stress ◽  
Machined Surface ◽  
Hybrid Neural Network ◽  
Marquardt Algorithm ◽  
Machined Parts

Surface integrity, such as surface roughness and residual stress, is an aspect of surface quality on machined parts. Residual stress in the machined surface and subsurface is affected by materials, machining conditions, and tool geometry. These residual stresses could affect the service qualify and component life significantly. Residual stress can be determined by empirical or numerical experiments for selected configurations, even if both are expensive procedures. This paper presents a hybrid neural network that is trained using Simulated Annealing (SA) and Levenberg-Marquardt Algorithm (LM) in order to predict the values of residual stresses in cutting and radial direction after the MQL face turning process accurately. To verify the performance of the proposed approach, the predicted results are compared with the results obtained by training an ANN using SA and LM separately. The results have shown that the hybrid neural network outperforms SA and LM in predicting machining induced surface integrity that is critical to determine the fatigue life of the components.

Nickel Superalloy Components Surface Integrity Control through Numerical Optimization

2014 ◽  
Vol 611-612 ◽  
pp. 1396-1403 ◽  
Author(s):  
Antonio del Prete ◽  
Rodolfo Franchi ◽  
Emilia Mariano
Keyword(s):  
Residual Stress ◽  
Surface Integrity ◽  
Removal Rate ◽  
White Layer ◽  
Optimization Procedure ◽  
Tool Geometry ◽  
Stress Profile ◽  
Machined Surface ◽  
Residual Stress Profile ◽  
Target Profile

Different parameters are used to evaluate the machined surface quality; roughness, residual stress and white layer are the most common factors that affect the surface integrity. Residual stress, in addition, are one of the main factors that influence the component fatigue life. Superficial residual stresses depend on different factors, such as cutting parameters and tool geometry. This article describes the development of an automated optimization procedure that allows the matching of a residual stress Target Profile by varying process parameters and tool geometry for a typical aeronautic superalloy, such as Waspaloy, for which a reliable numerical model has been developed for comparison to experimental data. The objective of this procedure is to maximize the Material Removal Rate under physical constraints represented by appropriate limits assigned to: Cutting Force, Thrust Force, Tool Rake Temperature and residual stress Target Profile. The developed optimization procedure has shown its effectiveness to match a given residual stress profile in accordance to process responses numerically evaluated.

Role of Tool Flank Wear and Machining Speed in Developing of Residual Stress in Machined Surface During High Speed Machining of Titanium Alloys

2015 ◽  
Author(s):  
Xueping Zhang ◽  
Rajiv Shivpuri ◽  
Anil K. Srivastava
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
High Speed ◽  
Flank Wear ◽  
Tool Geometry ◽  
High Speed Machining ◽  
Machined Surface ◽  
Tool Flank Wear ◽  
Machining Speed

Residual stresses generated from finish machining have a significant impact on the fatigue life of mechanical components by controlling crack initiation and propagation processes in their near subsurface. As governing variables, tool geometry, tool wear, machining parameter, work material property, and lubrication conditions have been widely studied to determine their effects on residual stress pattern in machined surface and subsurface. Among those parameters, tool flank wear was seldom fully investigated although tool flank wear, as well as machining speed, has been identified as the most important contributor to residual stress. Especially, tool flank wear becomes more significant due to the poor work thermal property during the high speed machining of titanium Ti-6Al-4V alloy. This study aims to investigate the combined role of tool flank wear and machining speed in developing residual stress in the machining of titanium alloy using finite element method. A microstructure sensitive material model based on Self Consistent Method (SCM) is adopted to incorporate the phase state and its transformations during machining cycle. Critical flank wear land and corresponding machining speeds are identified, beyond which compressive residual stresses are transferred into tensile residual stresses. High machining speeds demonstrate a distinct influence on residual stresses by means of promoting tool flank wear rate. The numerical simulation results are validated by empirical data provided in previous research.

Prediction of Residual Stress in Hard Turning of AISI 52100 Using 2D FEM

2007 ◽  
Vol 10-12 ◽  
pp. 688-691 ◽  
Author(s):  
Zhong Qiu Wang ◽  
J. Sun ◽  
Jian Feng Li ◽  
I. Al-Zkeri
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Cutting Forces ◽  
Hard Turning ◽  
Tool Geometry ◽  
Machined Surface ◽  
Fem Model ◽  
User Subroutine ◽  
Aisi 52100

Residual stress on the machined surface and the subsurface is one of the most important factors that can influence the service quality of a component, such as fatigue life, tribological properties, and distortion. In this work, a 2D FEM model of AISI 52100 hard turning processes is setup. The material properties are widely selected to describe the material property more precisely. By using user subroutine named Konti-Cut, the steady state of cutting process is simulated and the cutting forces and residual stresses in this time are investigated. By comparing the cutting forces, the FEM model can gives quite good appliance with experimental data. And the basic relations between residual stresses and cutting parameter, tool geometry are drawn.

FEM Simulation of the Residual Stress in the Machined Surface Layer for High-Speed Machining

2006 ◽  
Vol 315-316 ◽  
pp. 140-144 ◽  
Author(s):  
Su Yu Wang ◽  
Xing Ai ◽  
Jun Zhao ◽  
Z.J. Lv
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Surface Layer ◽  
Residual Stresses ◽  
High Speed ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
High Speed Machining ◽  
Machined Surface ◽  
Cutting Model

An orthogonal cutting model was presented to simulate high-speed machining (HSM) process based on metal cutting theory and finite element method (FEM). The residual stresses in the machined surface layer were obtained with various cutting speeds using finite element simulation. The variations of residual stresses in the cutting direction and beneath the workpiece surface were studied. It is shown that the thermal load produced at higher cutting speed is the primary factor affecting the residual stress in the machined surface layer.

Model-based sensitivity analysis of machining-induced residual stress under minimum quantity lubrication

2015 ◽  
Vol 231 (9) ◽  
pp. 1528-1541 ◽  
Author(s):  
Xia Ji ◽  
Steven Y Liang
Keyword(s):  
Residual Stress ◽  
Sensitivity Analysis ◽  
Cutting Force ◽  
Cutting Temperature ◽  
Minimum Quantity Lubrication ◽  
Cutting Parameters ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
Mixture Ratio ◽  
Minimum Quantity

This article presents a sensitivity analysis of residual stress based on the verified residual stress prediction model. The machining-induced residual stress is developed as a function of cutting parameters, tool geometry, material properties, and lubrication conditions. Based on the residual stress predictive model, the main effects of the cutting force, cutting temperature, and residual stress are quantitatively analyzed through the cosine amplitude method. The parametric study is carried out to investigate the effects of minimum quantity lubrication parameters, cutting parameters, and tool geometry on the cutting performances. Results manifest that the cutting force and residual stress are more sensitive to the heat transfer coefficient and the depth of cut, while the cutting temperature is more sensitive to the cutting speed. Large maximum compressive residual stress is obtained under a lower flow rate of minimum quantity lubrication, small depth of cut, and the proper air–oil mixture ratio. This research can support the controlling and optimization of residual stress in industrial engineering by strategically adjusting the application parameters of minimum quantity lubrication.

Surface Integrity of Die Material in High Speed Hard Machining, Part 1: Micrographical Analysis

1999 ◽  
Vol 122 (4) ◽  
pp. 620-631 ◽  
Author(s):  
T. I. El-Wardany ◽  
H. A. Kishawy ◽  
M. A. Elbestawi
Keyword(s):  
Tool Wear ◽  
Residual Stresses ◽  
Tool Steel ◽  
Surface Integrity ◽  
High Speed ◽  
Cutting Conditions ◽  
Metallographic Analysis ◽  
Tool Geometry ◽  
Machined Surface ◽  
Geometrical Defects

The effects of cutting conditions and tool wear on chip morphology and surface integrity during high speed machining of D2 tool steel (60–62 Hrc) are investigated experimentally and analytically in this paper. Polycrystalline Cubic Boron Nitride (PCBN) tools are used in this investigation. The chips and the subsurface of the workpiece are examined using optical and scanning electron microscopy. Microhardness measurements are performed on the surface and subsurface of the workpiece. The X-ray diffraction technique is used to measure the residual stresses induced in the machined surface. The paper is divided into two parts. Part 1 presents the results obtained from the micrographical analysis of the chips and the surfaces produced. Part 2 deals with microhardness and residual stresses of the machined surface. The micrographical analysis of the chips produced shows that different mechanisms of chip formation exist depending on the magnitude of the cutting pressure and tool wear. Saw toothed chips are produced during the machining of D2 tool steel if the cutting pressure exceeds approximately 4000 MPa. The metallographic analysis of the surface produced illustrates the damaged surface region that contains geometrical defects and changes in the subsurface metallurgical structure. The types of surface damage are dependent on the cutting conditions, tool geometry and the magnitude of the wear lands. [S1087-1357(00)00104-0]

Local Residual Stress Distribution at the Tooth Root Surface of a Broached Steel Component

2012 ◽  
Vol 706-709 ◽  
pp. 1731-1736 ◽  
Author(s):  
Tobias Strauss ◽  
Harald Meier ◽  
Jens Gibmeier ◽  
Volker Schulze ◽  
Alexander Wanner
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Surface Hardness ◽  
Case Hardening ◽  
Dry Cutting ◽  
Machined Surface ◽  
Near Surface ◽  
Case Hardening Steel

Broaching is an important technique for creating tooth structures in mechanical components. In the present work, the effects of the broaching process on the material state in the near surface region at the root of the tooth was analyzed. The studies were carried out on broached plates made from case hardening steel SAE 5120. The cutting speed and machining condition (cooling lubricant, dry machining) were varied. During broaching with a TiAlN coated tool the cutting forces were monitored. Subsequently, the local residual stresses at the root of the tooth were determined using X-ray diffraction. Further, surface roughness and micro hardness measurements as well as microstructure analysis complement the results. The results indicate that cutting forces have a high influence on the development of the residual stress state at the machined surface whereas no significant effect on changes in surface hardness and microstructure could be observed. Dry cutting with relatively high cutting speeds (≥ 30m/min) result in low cutting forces and hence in high tensile residual stresses in broaching direction.

scholarly journals Effect of Cutting Conditions on the Residual Stresses Induced by Milling of AISI 1045 Steel

2019 ◽  
Vol 8 (2) ◽  
pp. 1462-1465 ◽  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Diffraction Method ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
Machining Processes ◽  
Machined Surface ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
1045 Steel

The nature of residual stresses caused by machining processes has been relevant to the study of component performance for decades. The concept that cutting parameters affect the magnitude and nature of residual stress is well known. In order to reduce the residual stresses on a machined surface, it is important to identify the extent of the effect of cutting conditions. This paper presents the effect of depth of cut and tool speed on milling induced residual stresses. Speed and depth of cut were varied when milling several AISI 1045 Steel specimens. Stresses were measured with the X-ray diffraction method and corroborated with mathematical modelling on an FEA software. A relationship between tool speed and residual stress, and depth of cut and residual stress was thus obtained.

The Influence of Chemical Composition on Residual Stresses in NiCoMo Alloy Deposits on 12 Ni Maraging Steel

2013 ◽  
Vol 768-769 ◽  
pp. 449-455 ◽  
Author(s):  
Zoran Bergant ◽  
Janez Grum
Keyword(s):  
Residual Stress ◽  
Chemical Composition ◽  
Residual Stresses ◽  
Base Material ◽  
Stress Generation ◽  
Hole Drilling ◽  
Residual Stress Field ◽  
Hole Drilling Method ◽  
Similar Chemical ◽  
Drilling Method

The in-plane residual stresses in laser cladded specimens, made of 12-nickel precipitation hardening maraging hot-working tool steel 1.2799 (SIST EN 10027-2) are analyzed using the hole drilling method. The CO2 laser was used to deposit the alloy NiCoMo-1 with significantly higher content of nickel and cobalt with austenitic microstructure at room temperature. The Nd:YAG laser was used to deposit the maraging alloy designated NiCoMo-2, with similar chemical composition as the base material. The comparison of residual stress field showed the sign and the magnitude of residual stresses depends on the chemical composition of the clad being deposited. The high tensile residual stresses were found in NiCoMo-1 layers and favorable compressive residual stresses were found in NiCoMo-2 layers. The metallurgical aspects of residual stress generation are discussed.

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