A Micro Milling Model Considering Metal Phases and Minimum Chip Thickness

2008 ◽  
Vol 375-376 ◽  
pp. 505-509 ◽  
Author(s):  
Jin Sheng Wang ◽  
Jia Shun Shi ◽  
Ya Dong Gong ◽  
G. Abba ◽  
Guang Qi Cai
Keyword(s):  
Cutting Forces ◽  
Chip Thickness ◽  
Milling Process ◽  
Micro Milling ◽  
Surface Generation ◽  
Minimum Chip Thickness ◽  
Experiment Validation ◽  
Metal Phases

In this paper, a micro milling model is brought forward. The influences of different metal phases and the minimum chip thickness are considered in the model. The cutting forces and the surface generation in the micro milling process are predicted. Through the experiment validation, the results correlate to the model very well.

Dynamic Simulation of the Micro-Milling Process Including Minimum Chip Thickness and Size Effect

2012 ◽  
Vol 504-506 ◽  
pp. 1269-1274 ◽  
Author(s):  
François Ducobu ◽  
Edouard Rivière-Lorphèvre ◽  
Enrico Filippi
Keyword(s):  
Size Effect ◽  
Cutting Forces ◽  
Mechanistic Model ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Milling Process ◽  
Cutting Conditions ◽  
Micro Milling ◽  
Minimum Chip Thickness ◽  
Physical Phenomena

Micro-milling with a cutting tool is a manufacturing technique that allows production of parts ranging from several millimeters to several micrometers. The technique is based on a downscaling of macroscopic milling process. Micro-milling is one of the most effective process to produce complex three-dimensional micro-parts, including sharp edges and with a good surface quality. Reducing the dimensions of the cutter and the cutting conditions requires taking into account physical phenomena that can be neglected in macro-milling. These phenomena include a size effect (nonlinear rising of specific cutting force when chip thickness decreases), the minimum chip thickness (under a given dimension, no chip can be machined) and the heterogeneity of the material (the size of the grains composing the material is significant as compared to the dimension of the chip). The aim of this paper is to introduce some phenomena, appearing in micromilling, in the mechanistic dynamic simulation software ‘dystamill’ developed for macro-milling. The software is able to simulate the cutting forces, the dynamic behavior of the tool and the workpiece and the kinematic surface finish in 2D1/2 milling operation (slotting, face milling, shoulder milling,…). It can be used to predict chatter-free cutting condition for example. The mechanistic model of the cutting forces is deduced from the local FEM simulation of orthogonal cutting. This FEM model uses the commercial software ABAQUS and is able to simulate chip formation and cutting forces in an orthogonal cutting test. This model is able to reproduce physical phenomena in macro cutting conditions (including segmented chip) as well as specific phenomena in micro cutting conditions (minimum chip thickness and size effect). The minimum chip thickness is also taken into account by the global model. The results of simulation for the machining of titanium alloy Ti6Al4V under macro and micro milling condition with the mechanistic model are presented discussed. This approach connects together local machining simulation and global models.

Mechanism of Cutting Force and Surface Generation in Dynamic Milling

1991 ◽  
Vol 113 (2) ◽  
pp. 160-168 ◽  
Author(s):  
D. Montgomery ◽  
Y. Altintas
Keyword(s):  
Cutting Force ◽  
Surface Finish ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Dominant Frequency ◽  
Milling Process ◽  
Cutting Edge ◽  
Surface Generation ◽  
Uncut Chip Thickness ◽  
Improved Model

An improved model of the milling process is presented. The model proposes a method of determining cutting forces in five distinct regions where the cutting edge travels during dynamic milling. Trochoidal motion of the milling cutter is used in determining uncut chip thickness. The kinematics of the cutter and workpiece vibrations are modelled, which identifies the orientation and velocity direction of the cutting edge during dynamic cutting. The model allows the prediction of forces and surface finish under rigid or dynamic cutting conditions. The proposed mechanism of chip thickness, force and surface generation is proven with simulation and experimental results. It is found that when the tooth passing frequency is selected to be an integer ratio of a dominant frequency of tool-workpiece structure in milling imprint of vibrations on the surface finish is avoided.

scholarly journals Development and validation of a meshless 3D material point method for simulating the micro-milling process

2018 ◽  
Author(s):  
Sabine Leroch ◽  
Stefan J Eder ◽  
Georg Ganzenmüller ◽  
Jose Luis Sandoval Murillo ◽  
Manel Rodriguez Ripoll
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Material Point Method ◽  
Milling Process ◽  
Material Point ◽  
Finite Element Simulations ◽  
Point Method ◽  
Micro Milling ◽  
3D Simulations

A meshless Generalized Interpolation Material Point Method for simulating the micro-milling process was developed. This method has several advantages over well-established approaches (such as finite elements) when it comes to large plastic strains and deformations, since it inherently does not suffer from tensileinstability problems. The feasibility of the developed material point model for simulating micro-milling is verified against finite element simulations and experimental data. The model is able to successfully predict experimentally measured cutting forces and determine chip temperatures in agreement with conventional finite element simulations. After having verified the approach, the model was applied to perform extensive numerical 3D simulations of the micro-milling process. The goal is to evaluate the response of the micro-milling cutting forces as function of the hardening behavior of the micro-milled material. The meshless 3D simulations reveal a dependency of tool force slopes (with respect to the uncut chip thickness) on the hard-ening parameters. Based on these findings, a new approach is outlined to determine hardening parametersdirectly from two micro-milling experiments with distinct, sufficiently large uncut chip thicknesses.

An experimental analysis of minimum chip thickness in micro-milling of two different titanium alloys

2020 ◽  
Vol 234 (12) ◽  
pp. 1486-1498 ◽  
Author(s):  
Kubilay Aslantas ◽  
Luqman KH Alatrushi ◽  
Fevzi Bedir ◽  
Yusuf Kaynak ◽  
Nihat Yılmaz
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Ti6al4v Alloy ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Minimum Chip Thickness ◽  
Burr Width

Micro-milling is a micro-mechanical cutting method used to obtain complex and three-dimensional micro geometries. Micro-cutting tools are used in the manufacturing of micro-components and the type of workpiece is also important for good surface quality and minimum burr. In this study, micro machinability of Ti6Al4V alloy which is used most frequently in micro-component production is compared with Ti5553 alloy. Micro-milling of Ti5553 alloy and comparison of the minimum chip thickness with Ti6Al4V were performed for the first time in this study. Using different cutting parameters, the variation of surface roughness, burr width, and cutting forces were investigated. The cutting tests were carried out on a specially designed and high-precision micro-milling test system using a TiCN-coated two-flute end mill of 0.6 mm diameter. According to the results, minimum chip thickness is approximately 0.3 times the edge radius of the cutting tool and does not vary with the alloy type. At feed rates smaller than the minimum chip thickness, both the cutting forces increase and the surface quality decreases. For both alloys, reduced feed rate and increased depth of cut lead to increased burr width. The burr widths in Ti6Al4V alloy are higher. At the end of the study, the limits of the cutting parameters where plowing occurred for the both alloys are clearly determined. In addition, the limits of the cutting parameter causing plowing have been confirmed by cutting forces, surface roughness, and burr formation.

Model of the instantaneous undeformed chip thickness in micro-milling based on tooth trajectory

2016 ◽  
Vol 232 (2) ◽  
pp. 226-239 ◽  
Author(s):  
Xiaohong Lu ◽  
Zhenyuan Jia ◽  
Furui Wang ◽  
Guangjun Li ◽  
Likun Si ◽  
...  
Keyword(s):  
Cutting Forces ◽  
Chip Thickness ◽  
Milling Process ◽  
Cutting Edge ◽  
Micro Milling ◽  
Undeformed Chip Thickness ◽  
Single Tooth ◽  
Extended Length ◽  
Manufacturing Errors ◽  
Tooth Cutting

Instantaneous undeformed chip thickness is one of the key parameters in modeling of micro-milling process. Most of the existing instantaneous undeformed chip thickness models in meso-scale cutting process are based on the trochoidal trajectory of the cutting edge, which neglect the influences of cutter installation errors, cutter-holder manufacturing errors, radial runout of the spindle and so forth on the instantaneous undeformed chip thickness. This article investigates the tooth trajectory in micro-milling process. A prediction model of radial runout of cutting edge is built, with consideration of the effects of the extended length of micro-milling cutter and the spindle speed. Considering the effects of cutting-edge trochoidal trajectory, radial runout of cutting edge and the minimum cutting thickness, a novel instantaneous undeformed chip thickness model is proposed, and the phenomenon of single-tooth cutting in micro-milling process is analyzed. Comparisons of cutting forces under different chip thickness models and experimental data indicate that this new model can be used to predict cutting forces.

An accurate instantaneous uncut chip thickness model combining runout effect in micro-milling using cutters with the non-uniform helix and pitch angles

2019 ◽  
Vol 234 (5) ◽  
pp. 859-870 ◽  
Author(s):  
Qiang Guo ◽  
Yan Jiang ◽  
Zhibo Yang ◽  
Fei Yan
Keyword(s):  
Tool Path ◽  
Chip Thickness ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Cutter Runout ◽  
Model Combining ◽  
Key Factor ◽  
Cutting Point ◽  
Instantaneous Uncut Chip Thickness

As a key factor, the accuracy of the instantaneous undeformed thickness model determines the force-predicting precision and further affects workpiece machining precision in the micro-milling process. The runout with five parameters affects the machining process more significantly compared with macro-milling. Furthermore, modern industry uses cutters with non-uniform pitch and helix angles more and more common for their excellent properties. In this article, an instantaneous undeformed thickness model is presented regarding cutter runout, variable pitch, and helix angles in the micro-milling process. The cutter edge with the cutter runout effect is modeled. Then, the intersecting ellipse between the plane vertical to the spindle axis and the cutter surface which is a cylinder can be gained. Based on this, the points, which are used to remove the material, on the ellipse as well as cutter edges are calculated. The true trochoid trajectory for each cutting point along the tool path is built. Finally, the instantaneous undeformed thickness values are computed using a numerical algorithm. In addition, this article analyzes runout parameters’ effects on the instantaneous undeformed thickness values. After that, helix and pitch angles’ effects on the instantaneous undeformed thickness are studied. Ultimately, the last section verifies the correctness and validity of the instantaneous undeformed thickness model based on the experiment conducted in the literature.

Dynamic cutting force prediction for micro end milling considering tool vibrations and run-out

2018 ◽  
Vol 233 (7) ◽  
pp. 2248-2261 ◽  
Author(s):  
Xuewei Zhang ◽  
Tianbiao Yu ◽  
Wanshan Wang
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Milling Process ◽  
Force Model ◽  
Dynamic Cutting Force ◽  
Micro End Milling ◽  
Tool Vibrations ◽  
End Milling Process

An accurate prediction of cutting forces in the micro end milling, which is affected by many factors, is the basis for increasing the machining productivity and selecting optimal cutting parameters. This paper develops a dynamic cutting force model in the micro end milling taking into account tool vibrations and run-out. The influence of tool run-out is integrated with the trochoidal trajectory of tooth and the size effect of cutting edge radius into the static undeformed chip thickness. Meanwhile, the real-time tool vibrations are obtained from differential motion equations with the measured modal parameters, in which the process damping effect is superposed as feedback on the undeformed chip thickness. The proposed dynamic cutting force model has been experimentally validated in the micro end milling process of the Al6061 workpiece. The tool run-out parameters and cutting forces coefficients can be identified on the basis of the measured cutting forces. Compared with the traditional model without tool vibrations and run-out, the predicted and measured cutting forces in the micro end milling process show closer agreement when considering tool vibrations and run-out.

Identification of the Cutting Forces Coefficients via Milling Process Simulation

2011 ◽  
Author(s):  
Sergey A. Voronov ◽  
Igor A. Kiselev ◽  
Maxim G. Yakovlev
Keyword(s):  
Cutting Forces ◽  
Chip Thickness ◽  
Element Model ◽  
Optimization Method ◽  
Milling Process ◽  
Force Model ◽  
Processed Material ◽  
A New Technique ◽  
The Mathematical Model ◽  
The Given

The paper is devoted to the description of a new technique (numerical and experimental) identification of the dependences between cutting forces and instantaneous chip thickness. It is required to measure only the cutting forces versus cutting conditions. Experimentally, for the given pair the processed material – the tool, coefficients of the cutting forces model are calculated by means of the optimization method (Nelder-Mead algorithm). The mathematical model of the milling process developed by authors on each step of the Nelder-Mead method is used for the process numerical simulation under given coefficients of the cutting force model. The elaborated numerical modeling algorithm allows investigating the dynamics and the kinematics of the milling process. The dynamic model of the tool, the algorithm of geometrical modeling of the instantaneous chip thickness, the finite element model of the detail are embedded into the whole model of the milling process.

3D FE-Based Modelling and Simulation of the Micro Milling Process

2012 ◽  
Vol 516 ◽  
pp. 634-639 ◽  
Author(s):  
Tao Wu ◽  
Kai Cheng
Keyword(s):  
Chip Formation ◽  
Cutting Forces ◽  
Reasonable Agreement ◽  
Large Deformations ◽  
Helix Angle ◽  
Milling Process ◽  
Modelling And Simulation ◽  
Micro Milling ◽  
3D Finite Element ◽  
Milling Performance

Modelling and simulation of the micro milling process has the potential to improve tool design and optimize cutting conditions. This paper presents a novel and effective 3D finite element (FE) based method for simulating the micro milling process under large deformations. A tooling model incorporating a helix angle is developed for cutting forces, tooling temperature and chip formation prediction. The proposed approach is experimentally validated and the simulated micro milling performance such as micro chip formation and cutting forces are in reasonable agreement with the measured results in cutting trials.

Cutting forces analysis of micro-milling process on Inconel 718 – a finite element approach

2020 ◽  
Vol 11 (02) ◽  
pp. 2050011
Author(s):  
Padmaja Tripathy ◽  
Kalipada Maity
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Inconel 718 ◽  
Cutting Speed ◽  
Fem Analysis ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Parameters

This paper presents a modeling and simulation of micro-milling process with finite element modeling (FEM) analysis to predict cutting forces. The micro-milling of Inconel 718 is conducted using high-speed steel (HSS) micro-end mill cutter of 1mm diameter. The machining parameters considered for simulation are feed rate, cutting speed and depth of cut which are varied at three levels. The FEM analysis of machining process is divided into three parts, i.e., pre-processer, simulation and post-processor. In pre-processor, the input data are provided for simulation. The machining process is further simulated with the pre-processor data. For data extraction and viewing the simulated results, post-processor is used. A set of experiments are conducted for validation of simulated process. The simulated and experimental results are compared and the results are found to be having a good agreement.

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