scholarly journals Influence of Chatter of VMC Arising During End Milling Operation and Cutting Conditions on Quality of Machined Surface

1970 ◽  
Vol 2 (1) ◽  
Author(s):  
A.K.M.N. Amin, M.A. Rizal, and M. Razman
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Metal Removal ◽  
End Milling ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
End Mill ◽  
Machined Surface ◽  
Operating Cycle ◽  
Wide Range

Machine tool chatter is a dynamic instability of the cutting process. Chatter results in poor part surface finish, damaged cutting tool, and an irritating and unacceptable noise. Exten¬sive research has been undertaken to study the mechanisms of chatter formation. Efforts have been also made to prevent the occurrence of chatter vibration. Even though some progress have been made, fundamental studies on the mechanics of metal cutting are necessary to achieve chatter free operation of CNC machine tools to maintain their smooth operating cycle. The same is also true for Vertical Machining Centres (VMC), which operate at high cutting speeds and are capable of offering high metal removal rates. The present work deals with the effect of work materials, cutting conditions and diameter of end mill cutters on the frequency-amplitude characteristics of chatter and on machined surface roughness. Vibration data were recorded using an experimental rig consisting of KISTLER 3-component dynamometer model 9257B, amplifier, scope meters and a PC.  Three different types of vibrations were observed. The first type was a low frequency vibration, associated with the interrupted nature of end mill operation. The second type of vibration was associated with the instability of the chip formation process and the third type was due to chatter. The frequency of the last type remained practically unchanged over a wide range of cutting speed.  It was further observed that chip-tool contact processes had considerable effect on the roughness of the machined surface.Key Words: Chatter, Cutting Conditions, Stable Cutting, Surface Roughness.

The Investigation of Prediction Surface Roughness from Machining Forces in End Milling Processes

2011 ◽  
Vol 486 ◽  
pp. 91-94 ◽  
Author(s):  
Jabbar Abbas ◽  
Amin Al-Habaibeh ◽  
Dai Zhong Su
Keyword(s):  
Surface Roughness ◽  
End Milling ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Irregular Waves ◽  
Depth Of Cut ◽  
End Mill ◽  
Machined Surface ◽  
Machining Forces ◽  
Mill Cutter

Surface roughness is one of the most significant parameters to determine quality of machined parts. Surface roughness is defined as a group of irregular waves in the surface, measured in micrometers (μm). Many investigations have been performed to verify the relationship between surface roughness and cutting parameters such as cutting speed, feed rate and depth of cut. To predict the surface produced by end milling, surface roughness models have been developed in this paper using the machining forces by assuming the end mill cutter as a cantilever beam rigidly or semi- rigidly supported by tool holder. An Aluminium workpiece and solid carbide end mill tools are used in this work. Model to predict surface roughness has been developed. Close relationship between machined surface roughness and roughness predicted using the measured forces signals.

An Analysis on Temperature & Surface Roughness during End Milling of Ti-6Al-4V Alloy

2014 ◽  
Vol 592-594 ◽  
pp. 38-42 ◽  
Author(s):  
S. Samsudeensadham ◽  
Vijayan Krishnaraj
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Metal Cutting ◽  
End Milling ◽  
Cutting Speed ◽  
Critical Issue ◽  
Vital Role ◽  
Effect Of Temperature ◽  
Regression Equations ◽  
Machined Surface

The heat produced in metal cutting process is one of the most critical issue in machining of titanium alloys. High temperature in metal cutting degrades the tool life, surface integrity, size accuracy and machining efficiency dramatically. The temperature generated during end milling of titanium alloy, has been measured using Thermo camera. Surface roughness plays a vital role in evaluating and measuring the quality of the machined surface. During the experiments, cutting speed and feed rate have been changed to analyse the effect of temperature and surface roughness. It is observed that cutting speed has the greater effect on temperature and surface roughness during end milling of titanium alloy. The regression equations generated have better fit which can be used for optimization.

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.

Development of the cBN Electroplated End-Mill for High Precision Machining of CFRP

2020 ◽  
Author(s):  
Shinnosuke Yamashita ◽  
Tatsuya Furuki ◽  
Hiroyuki Kousaka ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
...  
Keyword(s):  
Surface Roughness ◽  
End Milling ◽  
Drop Out ◽  
End Mill ◽  
Machined Surface ◽  
Side Milling ◽  
Reinforced Plastics ◽  
Milled Surface ◽  
Grinding Conditions ◽  
Grinding Tool

Abstract Recently, the demand of carbon fiber reinforced plastics (CFRP) has been rapidly increased in various fields. In most cases, CFRP products requires a finish machining like cutting or grinding. In the case of an end-milling, burrs and uncut fibers are easy to occur. On the other hand, a precise machined surface and edge will be able to obtain by using the grinding tool. Therefore, this research has been developed a novel the cBN electroplated end-mill that combined end-mill and grinding tool. In this report, the effectiveness of developed tool was investigated. First, the developed tool cut the CFRP with side milling. As the result, the cBN abrasives that were fixed on the outer surface of developed tool did not drop out. Next, the end-milled surface of CFRP was ground with the developed tool under several grinding conditions based on the Design of Experiment. Consequently, the optimum grinding condition that can obtain the sharp edge which does not have burrs and uncut fibers was found. However, surface roughness was not good enough. Thus, an oscillating grinding was applied. In addition, the theoretical surface roughness formula in case using the developed tool was formularized. As the result, the required surface roughness in the airplane field was obtained.

Cutting Forces and Surface Roughness in High-Speed End Milling of Ti6Al4V

2013 ◽  
Vol 589-590 ◽  
pp. 76-81
Author(s):  
Fu Zeng Wang ◽  
Jun Zhao ◽  
An Hai Li ◽  
Jia Bang Zhao
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Cutting Forces ◽  
High Speed ◽  
End Milling ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Wide Range ◽  
Radial Depth ◽  
Coated Carbide

In this paper, high speed milling experiments on Ti6Al4V were conducted with coated carbide inserts under a wide range of cutting conditions. The effects of cutting speed, feed rate and radial depth of cut on the cutting forces, chip morphologies as well as surface roughness were investigated. The results indicated that the cutting speed 200m/min could be considered as a critical value at which both relatively low cutting forces and good surface quality can be obtained at the same time. When the cutting speed exceeds 200m/min, the cutting forces increase rapidly and the surface quality degrades. There exist obvious correlations between cutting forces and surface roughness.

An Approach to Improve Cutting Performance in Micromilling of Titanium Alloy

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Yunn-Shiuan Liao ◽  
Tsung-Hsien Li ◽  
Yi-Chen Liu
Keyword(s):  
Carbon Dioxide ◽  
Surface Roughness ◽  
Titanium Alloy ◽  
Flank Wear ◽  
End Milling ◽  
Cutting Speed ◽  
Liquid Carbon ◽  
Dry Cutting ◽  
Machined Surface ◽  
Liquid Carbon Dioxide

Abstract Application of liquid carbon dioxide to improve cutting performance in micro-end milling of Ti-6Al-4V titanium alloy was proposed in this study. It was found that the machined roughness decreased with the cutting speed as observed in the conventional cutting, when a 0.5 mm diameter end milling cutter was used in dry cutting. But, the tiny and shattered chips produced by the use of 0.3 mm diameter cutter could adhere on the machined surface and deteriorate surface finish, if the cutting speed was higher than 40 m/min. Cutting temperature was effectively decreased by applying liquid carbon dioxide during micromilling, which in turn reduced the amount of chips adhering on the machined surface and lowered flank wear. The surface roughness Ra at a cutting speed of 70 m/min was improved from 0.09 μm under dry cutting to 0.04 μm under the liquid carbon dioxide assisted cutting condition. And there were no flank wear and very few burrs left on the machined surface for the condition used in the experiment. The height of the burrs was only 25% of that under dry cutting. More, minimum quantity lubrication (MQL) was proposed to be applied together with the liquid carbon dioxide to enhance lubrication effect. It was noted that the machined surface roughness was further decreased by 15% as compared with that when the liquid carbon dioxide was applied alone. The height of burrs was reduced from 32 μm to 16 μm.

Experimental Research of Effective Cutting Speed Influence on Surface Roughness in Ball End Milling of C45 Material with Hardness 34 HRC

2014 ◽  
Vol 657 ◽  
pp. 53-57 ◽  
Author(s):  
Sándor Ravai Nagy ◽  
Ioan Paşca ◽  
Mircea Lobonțiu ◽  
Mihai Banica
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Experimental Research ◽  
Inclination Angle ◽  
Cutting Tool ◽  
End Milling ◽  
Cutting Speed ◽  
Cnc Machine Tools ◽  
Machined Surface ◽  
Ball End Milling

Machining of Complex Concave or Convex Surfaces Requires the Use of Ball End Milling Cutters. Obtaining the Expected Surface Quality Compete Various Technological Factors which should be Taken into Account. Following the Machining of the Surface with Different Inclination Angles between the Cutting Tool Axes and the Machined Surface, Significant Changes of the Surface Roughness have been Observed. Based on the Tests Performed, we can Determine the Range of the Tool Inclination Angle, which is the Best for the Surface Quality. we have also Made a Correlation between the Cutting Speeds, Inclination Angle of the Cutting Tool Toward the Machined Surface for an Obtained Surface Quality. the Presented Results are Based on Experimental Research in Industrial Conditions by Using CNC Machine Tools with 5 Axes. the Tests have been Performed on the C45 Material, Heat Treated to 34HRC.

Investigating the Effect of Cutting Speed Variation on Surface Roughness of 7136 Aluminum Alloy in End Milling

2015 ◽  
Vol 809-810 ◽  
pp. 129-134 ◽  
Author(s):  
Alina Bianca Bonţiu Pop ◽  
Mircea Lobonţiu
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Metal Cutting ◽  
End Milling ◽  
Cutting Speed ◽  
Processing Parameters ◽  
Milling Process ◽  
Future Research ◽  
Cutting Depth ◽  
Speed Variation

Surface quality is affected by various processing parameters and inherent uncertainties of the metal cutting process. Therefore, the surface roughness anticipation becomes a real challenge for engineers and researchers. In previous researches [1] I have investigated the feed rate influence on surface roughness and manufacturing time reduction. The 7136 aluminum alloy was machined by end milling operation using standard tools for aluminum machining. The purpose of this paper is to identify by experiments the influence of cutting speed variation on surface roughness. The scientific contribution brought by this research is the improvement of the end milling process of 7136 aluminum alloy. This material is an aluminum alloy developed by Universal Alloy Corporation and is used in the aircraft industry to manufacture parts from extruded profiles. The research method used to solve the problem is experiment. A range of cutting speeds was used while the cutting depth and the feed per tooth were constrained per minimum and maximum requirements defined for the given cutting tool. The experiment was performed by using a 16 mm End milling cutter, holding two indexable cutting inserts. The machine used for the milling tests was a HAAS VF2 CNC. The surface roughness (response) was measured by using a portable surface roughness tester (TESA RUGOSURF 20 Portable Surface Finish Instrument). Following the experimental research, results were obtained which highlight the cutting speed influence on surface roughness. Based on these results we created roughness variation diagrams according to the cutting speed for each value of feed per tooth and cutting depth. The final results will be used as data for future research.

SURFACE TEXTURE ANALYSIS AFTER BALL END MILLING WITH VARIOUS SURFACE INCLINATION OF HARDENED STEEL

2014 ◽  
Vol 21 (1) ◽  
pp. 145-156 ◽  
Author(s):  
Szymon Wojciechowski ◽  
Paweł Twardowski ◽  
Michał Wieczorowski
Keyword(s):  
Surface Roughness ◽  
Inclination Angle ◽  
Surface Texture ◽  
Cutting Speed ◽  
Power Density Spectrum ◽  
End Mill ◽  
Ball End Mill ◽  
Machined Surface ◽  
Surface Irregularities ◽  
Surface Inclination

Abstract In this paper, an analysis of various factors affecting machined surface texture is presented. The investigation was focused on ball end mill inclination against the work piece (defined by surface inclination angle a. Surface roughness was investigated in a 3D array, and measurements were conducted parallel to the feed motion direction. The analysis of machined surface irregularities as a function of frequency (wavelength A), on the basis of the Power Density Spectrum - PDS was also carried out. This kind of analysis is aimed at valuation of primary factors influencing surface roughness generation as well as its randomness. Subsequently, a surface roughness model including cutter displacements was developed. It was found that plain cutting with ball end mill (surface inclination angle a= 0°) is unfavorable from the point of view of surface roughness, because in cutter’s axis the cutting speed vc ~ 0 m/min. This means that a cutting process does not occur, whereas on the machined surface some characteristics marks can be found. These marks do not appear in case of a* 0°, because the cutting speed vc * 0 on the fill I length of the active cutting edge and as a result, the machined surface texture is more homogenous. Surface roughness parameters determined on the basis of the model including cutter displacements are closer to experimental data for cases with inclination angles a* 0°, in comparison with those determined for plain cutting (a= 0°). It is probably caused by higher contribution in surface irregularities generation of plastic and elastic deformations cumulated near the cutter’s free end than kinematic and geometric parameters, as well as cutter displacements.

scholarly journals Optimization of Cutting Conditions in End Milling Process with the Approach of Particle Swarm Optimization

2011 ◽  
pp. 120-124
Author(s):  
Vikas Pare ◽  
Geeta Agnihotri ◽  
C.M. Krishna
Keyword(s):  
Surface Roughness ◽  
Particle Swarm Optimization ◽  
Surface Finish ◽  
Metal Cutting ◽  
End Milling ◽  
Optimization Technique ◽  
Particle Swarm ◽  
Swarm Optimization ◽  
Wide Range ◽  
Input Variables

Milling is one of the progressive enhancements of miniaturized technologies which has wide range of application in industries and other related areas. Milling like any metal cutting operation is used with an objective of optimizing surface roughness at micro level and economic performance at macro level. In addition to surface finish, modern manufacturers do not want any compromise on the achievement of high quality, dimensional accuracy, high production rate, minimum wear on the cutting tools, cost saving and increase of the performance of the product with minimum environmental hazards. In order to optimize the surface finish, the empirical relationships between input and output variables should be established in order to predict the output. Optimization of these predictive models helps us to select appropriate input variables for achieving the best output performance. In this paper, four input variables are selected and surface roughness is taken as output variable. Particle swarm optimization technique is used for finding the optimum set of values of input variables and the results are compared with those obtained by GA optimization in the literature.

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