High-Accuracy Machining of Thin-Walled Workpiece by Non-Rotational Tool-Analysis of Machining Accuracy Based on Deflection of Tool and Workpiece Using FEM-

2010 ◽  
Vol 4 (3) ◽  
pp. 243-251 ◽  
Author(s):  
Hiroyasu Iwabe ◽  
◽  
Hideaki Matsuhashi ◽  
Hayato Akutsu ◽  
Tomoyuki Shioya ◽  
...  
Keyword(s):  
Fem Analysis ◽  
Depth Of Cut ◽  
Machining Accuracy ◽  
Thin Wall ◽  
Shape Error ◽  
Machined Surface ◽  
Dimensional Error ◽  
Tool Edge ◽  
Deflection Analysis ◽  
Predicted Values

In this paper, the FEM analysis and the machining of a workpiece using a non-rotational tool are attempted in order to produce a highly accurate surface on a thin wall. Also, the machining accuracy of the thin wall produced by the non-rotational tool is compared with that produced by an end mill. The main results are as follows. (1) FEM models for the tool and workpiece are made and the machining accuracy is predicted based on the deflection analysis using FEM due to the cutting force. (2) The tendency of the shape of machined surface is almost coincident with that of the predicted shape, so the propriety of the method of analysis is verified. (3) Both dimensional and shape error on the inside and outside surfaces of the workpiece produced by the non-rotational tool prove larger than the predicted values. Although the shape error proved a little larger than the predicted value, the target value of 5μm was achieved. (4) It is shown that the dimensional error due to under cutting decreases with the decrease in the radius of the tool edge. And also, on and after the second cutting process, the cutting at the commanded depth of cut was achieved even if the micro depth of cut.

Machining Evaluation of High-Speed Milling for Thin-Wall Machining of Al7075-T651

2014 ◽  
Vol 541-542 ◽  
pp. 785-791 ◽  
Author(s):  
Joon Young Koo ◽  
Pyeong Ho Kim ◽  
Moon Ho Cho ◽  
Hyuk Kim ◽  
Jeong Kyu Oh ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
Cutting Forces ◽  
High Speed ◽  
Surface Condition ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
Thin Wall ◽  
Machined Surface ◽  
High Speed Milling

This paper presents finite element method (FEM) and experimental analysis on high-speed milling for thin-wall machining of Al7075-T651. Changes in cutting forces, temperature, and chip morphology according to cutting conditions are analyzed using FEM. Results of machining experiments are analyzed in terms of cutting forces and surface integrity such as surface roughness and surface condition. Variables of cutting conditions are feed per tooth, spindle speed, and axial depth of cut. Cutting conditions to improve surface integrity were investigated by analysis on cutting forces and surface roughness, and machined surface condition.

Investigation on Affecting Factors of Vibration in Milling Harden Steel Assembled with Different Hardness

2013 ◽  
Vol 546 ◽  
pp. 137-141 ◽  
Author(s):  
Yang Yu Wang ◽  
Hao Dong Zhou ◽  
Dong Hui Wen ◽  
Shi Ming Ji ◽  
Hui Qiang Wang
Keyword(s):  
End Milling ◽  
Vibration Signal ◽  
Cutting Parameters ◽  
Transitional Zone ◽  
Depth Of Cut ◽  
Machining Accuracy ◽  
Affecting Factors ◽  
Machined Surface ◽  
Reasonable Choice ◽  
Milling Vibration

The milling vibration affects machined surface quality and the size of the error, and has an important impact on the machining accuracy. This paper studies the different cutting parameters on cutting conditions on milling vibration during ball end milling Cr12MoV hardened steel assembled with different hardness steels, and use LMS. Test. Lab software to analyze the vibration signal on the condition of different spindle speed milling direction, axial depth of cut, and the vibration signal of transitional zone and the non-transitional zone are compared, providing the basis for a reasonable choice of milling parameters.

FEM Analysis of Temperature in High Speed Cutting of TiAl6V4 Alloys

2012 ◽  
Vol 522 ◽  
pp. 201-205
Author(s):  
You Xi Lin ◽  
Cong Ming Yan ◽  
Zheng Ying Lin
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Temperature ◽  
Fem Analysis ◽  
Element Model ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Radial Depth

mprovements in modeling and simulation of metal cutting processes are required in advanced manufacturing technologies. A three dimensional fully thermal mechanical coupled finite element model had been applied to simulate and analyze the cutting temperature for high speed milling of TiAl6V4 titanium alloy. The temperature distribution induced in the tool and the workpiece was predicted. The effects of the milling speed and radial depth of cut on the maximum cutting temperature in the tool was investigated. The results show that only a rising of temperature in the lamella of the machined surface is influenced by the milling heat. The maximum temperature in the tool increases with increasing radial depth of cut and milling speed which value is 310°C at a speed of 60 m/min and increases to 740°C at 400m/min. The maximum temperature is only effective on a concentrated area at the cutting edge and the location of the maximum temperature moves away from the tool tip for higher radial depths of milling. The predicted temperature distribution during the cutting process is consistent with the experimental results given in the literature. The results obtained from this study provide a fundamental understanding the process mechanics of HSM of TiAl6V4 titanium alloys.

scholarly journals Improved Method for Synchronizing Motion Accuracy of Linear and Rotary Axes Under Constant Feed Speed Vector at End Milling Point – Investigation of Motion Error Under NC-Commanded Motion –

2019 ◽  
Vol 13 (5) ◽  
pp. 679-690 ◽  
Author(s):  
Takamaru Suzuki ◽  
Kazuki Yoshikawa ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Takakazu Ikegami ◽  
...  
Keyword(s):  
End Milling ◽  
Research Work ◽  
Free Form ◽  
Machining Accuracy ◽  
Feed Speed ◽  
Shape Error ◽  
Control Coefficient ◽  
Machined Surface ◽  
Motion Error ◽  
Rotary Axis

A 5-axis machining center (5MC) is noted for its synchronous control capability, making it a feasible tool for quickly and accurately machining complicated three-dimensional surfaces such as propellers and hypoid gears as it is equipped with a direct-drive (DD) motor in the rotary axis. The current research work identified the necessity of improving both the accuracy of the machined shape and the consistency of the free-form machined surface. A method for maintaining the feed speed vector at the milling point by controlling two linear axes and the rotary axis of a 5MC to improve the quality of the machined surface was investigated. Additionally, a method was proposed for reducing the shape error of machined workpieces by considering differences in the servo characteristics of the three axes. The shape error was significantly reduced by applying the proposed method using a precedent control coefficient determined via calculations. To maintain the feed speed vector at the milling point in the machining of complex shapes, rapid velocity change in each axis is often required, leading to inaccuracy caused by torque saturation at a DD motor in the rotary axis. The results of this study indicate that torque saturation can be evaluated via simulation and that the machining accuracy and consistency can be improved by accounting for these errors using the proposed precedent control coefficient method.

Experimental Study on Milling Hardened SKD Steel Using Micro CBN Ball-End Mills

2010 ◽  
Vol 126-128 ◽  
pp. 773-778
Author(s):  
Yung Tien Liu ◽  
Neng Hsin Chiu ◽  
Yen Chun Lin ◽  
Chih Liang Lai ◽  
Yu Fu Lin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
End Milling ◽  
Milling Process ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Machined Surface ◽  
Performance Function ◽  
End Mills

Micro ball-end milling process features the ability of machining complex surfaces, precision machining accuracy, and excellent machined surface roughness. However, because the diameter of a micro milling tool is very small, a rapid progress of tool wear or even tool breakage usually happens when machining a high-strength hardened mold steel using improper machining parameters. As a result, the machining cost would rise due to the quality defect in machined workpiece. In this study, to investigate how the machining parameters affect the cutting behaviors, a series of experiments using micro CBN ball-end mills with a diameter of 0.5 mm were performed to cut the SKD11 mold steel with hardness of HRC 61. The machining parameters are selected as the feeding speed (f) being 840, 960 and 1,080 mm/min, depth of cut (ap) being 30, 45, 60 μm, and spindle speed (vs) being fixed as 30,000 rpm. According to the experimental results, the measured three-axis cutting forces, flank wears, and surface roughness of machined workpiece are highly related to the cutting length. It is expected that the measured results can be used to construct a performance function of a micro ball-end tool. With referring to the performance function, the tool life can be well expected, and thus a progress in machining efficiency without tool failure can be achieved.

Surface Roughness Identification in End Milling Using Vibration Signals and Fuzzy Clustering

2016 ◽  
Author(s):  
Issam Abu-Mahfouz ◽  
Amit Banerjee ◽  
A. H. M. Esfakur Rahman
Keyword(s):  
Surface Roughness ◽  
Fuzzy Clustering ◽  
Wavelet Transforms ◽  
Fourier Transforms ◽  
End Milling ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Machined Surface ◽  
Vibration Signals

The study presented involves the identification of surface roughness in Aluminum work pieces in an end milling process using fuzzy clustering of vibration signals. Vibration signals are experimentally acquired using an accelerometer for varying cutting conditions such as spindle speed, feed rate and depth of cut. Features are then extracted by processing the acquired signals in both the time and frequency domain. Techniques based on statistical parameters, Fast Fourier Transforms (FFT) and the Continuous Wavelet Transforms (CWT) are utilized for feature extraction. The surface roughness of the machined surface is also measured. In this study, fuzzy clustering is used to partition the feature sets, followed by a correlation with the experimentally obtained surface roughness measurements. The fuzzifier and the number of clusters are varied and it is found that the partitions produced by fuzzy clustering in the vibration signal feature space are related to the partitions based on cutting conditions with surface roughness as the output parameter. The results based on limited simulations are encouraging and work is underway to develop a larger framework for online cutting condition monitoring system for end milling.

scholarly journals Surface Integrity Investigation to Determine Rough Milling Effects for Assessment of Machining Allowance for Subsequent Finish Milling of Alloy 718

2021 ◽  
Vol 5 (2) ◽  
pp. 48
Author(s):  
Jonas Holmberg ◽  
Anders Wretland ◽  
Johan Berglund ◽  
Tomas Beno ◽  
Anton Milesic Karlsson
Keyword(s):  
Surface Integrity ◽  
Milling Process ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Milling Operations ◽  
Milling Operation ◽  
Machining Allowance ◽  
Rough Milling

The planned material volume to be removed from a blank to create the final shape of a part is commonly referred to as allowance. Determination of machining allowance is essential and has a great impact on productivity. The objective of the present work is to use a case study to investigate how a prior rough milling operation affects the finish machined surface and, after that, to use this knowledge to design a methodology for how to assess the machining allowance for subsequent milling operations based on residual stresses. Subsequent milling operations were performed to study the final surface integrity across a milled slot. This was done by rough ceramic milling followed by finish milling in seven subsequent steps. The results show that the up-, centre and down-milling induce different stresses and impact depths. Employing the developed methodology, the depth where the directional influence of the milling process diminishes has been shown to be a suitable minimum limit for the allowance. At this depth, the plastic flow causing severe deformation is not present anymore. It was shown that the centre of the milled slot has the deepest impact depth of 500 µm, up-milling caused an intermediate impact depth of 400 µm followed by down milling with an impact depth of 300 µm. With merged envelope profiles, it was shown that the effects from rough ceramic milling are gone after 3 finish milling passes, with a total depth of cut of 150 µm.

Experiment Study on Deflection of Aluminum Alloy Thin-Wall Workpiece in Milling Process

2011 ◽  
Vol 697-698 ◽  
pp. 129-132 ◽  
Author(s):  
Bing Han ◽  
Cheng Zu Ren ◽  
X.Y. Yang ◽  
Guang Chen
Keyword(s):  
Aluminum Alloy ◽  
Coordinate Measuring Machine ◽  
Milling Process ◽  
Cnc Machining ◽  
Machining Accuracy ◽  
Thin Wall ◽  
Machining Center ◽  
Machining Errors ◽  
Alloy Material ◽  
Measuring Machine

The deflection of Aluminum alloy thin-wall workpiece caused by the milling force leads to additional machining errors and reduces machining accuracy. In this paper, a set of experiments of milling thin-wall workpiece were carried out to study the deflection of thin-wall workpiece. The workpieces, with different types of material and different thicknesses, were machined on CNC machining center. The deflections of workpiece were measured by a three-coordinate measuring machine. Effects of Aluminum alloy material and thickness on deflection are discussed based on the experimental data.

Grinding-aided electrochemical discharge drilling in the light of electrochemistry

2018 ◽  
Vol 233 (6) ◽  
pp. 1896-1909 ◽  
Author(s):  
VG Ladeesh ◽  
R Manu
Keyword(s):  
Material Removal Rate ◽  
Borosilicate Glass ◽  
Chemical Etching ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Accuracy ◽  
Hybrid Technique ◽  
Machined Surface ◽  
Influence Of Process Parameters ◽  
Electrochemical Discharge

The electrically non-conductive materials like glass, ceramics, quartz, etc. are of great interest for many applications in modern industries. Machining them with high quality and at a faster rate is a challenging task. In this study, a novel technique called grinding aided electrochemical discharge drilling (G-ECDD) is demonstrated which uses a hollow diamond core drill as the tool for performing electrochemical discharge machining of borosilicate glass. The new hybrid technique enhances the material removal rate and machining accuracy to several folds by combining the thermal melting action of discharges and grinding action of the abrasive tool. This paper presents the experimental investigation on the material removal rate during G-ECDD of glass while using different electrolytes. An attempt has been made to explore the influence of electrolyte temperature on G-ECDD performance by maintaining the electrolyte at different temperatures. Experiments were conducted using three different electrolytes which include NaOH, KOH, and the mixture of both. The results obtained from this study revealed that an increase in temperature will favor chemical etching as well as electrochemical reaction rate. Also, it was observed that heating the electrolyte leads to an increase in the bubble density and enhances the ion mobility. This causes the formation of gas film at a faster rate and thereby improving the discharge activity. Thus, machining will be done at a faster rate. Better results are obtained while using a mixture of NaOH and KOH. From the microscopic images of the machined surface, it was observed that material removal mechanism in G-ECDD is a combination of grinding action, electrochemical discharges, and chemical etching. Response surface methodology was adopted for studying the influence of process parameters on the performance of G-ECDD. The new technique of grinding aided electrochemical discharge drilling proved its potential to machine borosilicate glass and simultaneously offers good material removal rate, repeatability, and accuracy.

Thermal hardening and calculation of the mathematical model of face milling of parts made of steel 95X18-Sh to improve the quality of the surface layer

2021 ◽  
pp. 200-206
Author(s):  
I.N. Sedinin ◽  
V.F. Makarov
Keyword(s):  
Mathematical Model ◽  
Cutting Speed ◽  
Physical And Mechanical Properties ◽  
Face Milling ◽  
Experiment Planning ◽  
Depth Of Cut ◽  
Machined Surface ◽  
The Mathematical Model ◽  
Full Factorial

It is considered the complex of operations of the technological process for the heat treatment of steel 95X18-Sh, as a result of which the material of the samples increases the hardness to 59...61 HRC, and also improves the physical and mechanical properties. A full-scale full factorial experiment of face milling of samples was carried out using the method of mathematical planning. In the experiments, a high-precision machine and a carbide cutting tool were used. To calculate the values of the roughness function, the following are taken as independent variables: cutting speed, feed per tooth and depth of cut. In order to determine the coefficients of the linear equation, a central compositional orthogonal plan of the second order for three factors was used. A matrix of levels of variation of independent variable factors and a matrix of experiment planning were compiled. A regression analysis of the obtained experimental statistical data was carried out using the Microsoft Excel, Statistica and Wolfram Alpha programs. As a result of the calculations, a mathematical model of the roughness of the machined surface and optimal cutting conditions were determined.

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