Optimization of Cutting Conditions with an End Mill According to the Criterion of the Smallest Amplitude of Vibration

2021 ◽  
Vol 1037 ◽  
pp. 239-244
Author(s):  
Dmitriy Y. Topolov ◽  
Igor S. Boldyrev

The article discusses the issues of chatter damping during milling. The relationship between the amplitude of forced vibrations and the cutting speed has been established. The choice of the optimal values ​​of the cutting condition during end milling is proposed to ensure the minimum vibration amplitude.

1970 ◽  
Vol 2 (1) ◽  
Author(s):  
A.K.M.N. Amin, M.A. Rizal, and M. Razman

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.


2010 ◽  
Vol 97-101 ◽  
pp. 3108-3112
Author(s):  
Bing Yan ◽  
Chao Hui Xu ◽  
Wei Wang

The machining characteristics of hardened still for mould and die greatly affect the accuracy and productivity in industry. The physical modeling and simulation of ball end milling is investigated in this paper. The influence of cutting speed to the cutting mechanism in high speed cutting is taken into account and the momentum force of chip is introduced into the model. By analyzing the shape of the chips the relationship between the cutting speed and shear angle is obtained. The model has been tested on 718HH, with appropriate Seco tools. The validation shows that the adjustment between the model and the real force is adequate, both in shape and magnitude.


Author(s):  
Issam Abu-Mahfouz ◽  
Amit Banerjee ◽  
A. H. M. Esfakur Rahman

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.


2014 ◽  
Vol 800-801 ◽  
pp. 465-469
Author(s):  
An Shan Zhang ◽  
Xian Li Liu ◽  
Shu Cai Yang ◽  
Qi Zhang

Complex cavity generally is machined in 3 axis or 3+2 axis machine tools, it has large amount of metal to be removed. For complex cavity machining, the cutting speed of ball end mill`s head point is zero, which makes its end milling ability poor; Torus cutter `s flat bottom width is wide, which causes curvature interference and concave-uncut. So this article designs a new kind of cutter for complex cavity roughing and semi-finishing, which can improve ball end mill`s poor end milling ability and decrease flat-end width. The simulation results show that the new cutter`s feasibility of machining complex cavity is better, and it can obviously reduce the amount of owe cutting compared with the torus cutter; At the same time, the new cutter can improve machining efficiency by 32.4% compared with the ball end mill, and good surface can also be generated.


1999 ◽  
Vol 121 (4) ◽  
pp. 559-567 ◽  
Author(s):  
J. T. Roth ◽  
S. M. Pandit

Autoregressive models are fit to end-milling acceleration data and the Data Dependent Systems methodology is utilized to isolate the modal energies of the first and second multiples of the tooth pass frequency. The modal energies are shown to be closely linked to the wear curve and a detection scheme is developed that is capable of tracking the end-mill’s wear and providing an early warning of impending failure. Six life tests are conducted under varying conditions to demonstrate the capabilities of the detection scheme: standard cutting conditions, extreme cutting conditions, premature catastrophic failure and accelerometer placement. In all six cases, the detection scheme was able to provide a warning of impending failure several centimeters before the failure occurred.


2012 ◽  
Vol 538-541 ◽  
pp. 799-803 ◽  
Author(s):  
A.K.M. Nurul Amin ◽  
Muhd Hafiz B. Md. Saad ◽  
Muammer Din Arif

Tool steel - SKD 11 is frequently used in industries for making dies and molds. This grade is chosen for its toughness, strength, and hardness maintained up to high temperature. However, the same properties make the steel extremely difficult and expensive to machine using conventional approaches. Heat assisted machining has been found wide spread application in recent years to improve machinability of difficult-to-cut materials. This research paper presents the outcome of an investigation on heat assisted end milling of SKD 11 conducted on a vertical machining center using ball nose coated carbide inserts. The Design of Experiments (DoE) was done using the Response Surface Methodology, in order to develop empirical mathematical models of surface roughness and vibration in terms of cutting speed, feed, axial depth of cut, and heating temperature. The models were checked for significance using Analysis of Variance (ANOVA). 3-D response surface graphs of the interactions of primary cutting parameters with the responses were plotted. Optimization was then performed by using the desirability function approach. From the graphs and optimized results it was concluded that the primary input parameters could be controlled in order to reduce vibration amplitude and produce semi-finished machined surfaces applying induction heat assisted technique.


2020 ◽  
Vol 14 (1) ◽  
pp. 18-25
Author(s):  
Haruhiko Suwa ◽  
Soushi Sakamoto ◽  
Masafumi Nagata ◽  
Kazuhiro Tezuka ◽  
Tetsuo Samukawa ◽  
...  

Sintered tungsten carbide which has high hardness and high heat resistance, has been widely used in molds and dies. Research on the development of a cutting technology for sintered tungsten carbide (sintered WC-Co alloy) has been pursued mainly with the use of a turning process. We focused on building an efficient milling method for sintered tungsten carbide by using diamond-coated ball end tools, and have investigated their basic properties under specific cutting conditions. This study extends our previous work by enhancing cutting distance in the milling of sintered tungsten carbide, especially that with a “fine” WC grain. The surface roughness of cut workpieces is evaluated from the point of view of the quality of surface roughness. A series of cutting experiments under different cutting conditions were carried out, and the possibility of deriving a suitable cutting condition for the ball end milling of sintered tungsten carbide is discussed.


2015 ◽  
Vol 9 (2) ◽  
pp. 115-121 ◽  
Author(s):  
Hirohisa Narita ◽  

An evaluation system for calculating equivalent CO2emissions and machining costs is developed using an activity-based model. The system can evaluate a machining process from an NC program, workpiece information, and cutting tool information, and it can then calculate accurate equivalent CO2emissions and the machining cost. The cutting speed of an end mill operation is evaluated in terms of the equivalent CO2emission and the machining cost. Based on the results, optimal cutting conditions are determined to minimize the equivalent CO2emissions and the machining cost to the extent possible.


2012 ◽  
Vol 523-524 ◽  
pp. 109-112
Author(s):  
Fukuhito Nagata ◽  
Koji Akashi ◽  
Daisaku Ishibashi

The BTA tool is a tool for deep-hole drilling. The deep-hole which be machined by this tool has the excellent straightness and roughness. However, it's use a lot of cutting oil. Therefore, it will lead to environmental destruction. Thereupon, in this study, it is applied the near-dry system to the deep-hole drilling with BTA tool. In the previously, it was designed the experimental device with a double tube system, and the cutting experiments was carried out. In this system, the chip is discharged through inside of the inner tube. Frequently, the chip is cannot be divided by the adhesion on the cutting edge during drilling. Thereby, the chip was jammed into the inside of tool’s tube. It is tried experiments of various cutting conditions, cutting speed and feed rate, by tools with different geometry, height and width, of the chip-breaker. And, it is observed the discharge condition of chips, the chip’s shape and the situation of adhesion. As a result, it can be found the optimum cutting condition and tool’s geometry for a continuous chip’s discharge while the deep-hole is drilling by a BTA tool in near-dry system.


Author(s):  
Xuan-Truong Duong ◽  
Marek Balazinski ◽  
René Mayer

The initial tool wear during machining of titanium metal matrix composite (TiMMCs) is the result of several wear mechanisms: tool layer damage, friction - tribological wear, adhesion, diffusion and brace wear. This phenomenon occurs at the first instant and extends to only ten seconds at most. In this case the adhesive wear is the most important mechanism while the brace wear is considered as a resistance wear layer at the beginning of the steady wear period. In this paper, the effect of the initial tool wear and initial cutting conditions on tool wear progression and tool life is investigated. We proposed herein a new mathematical model based on the scatter wear and Lyapunov exponent to study quantitatively the “chaotic tool wear”. The Chaos theory, which has proved efficient in explaining how something changes in time, was used to demonstrate the dependence of the tool life on the initial cutting conditions and thus contribute to a better understanding of the influence of the initial cutting condition on the tool life. Based on the chaotic tool wear model, the scatter wear dimension and Lyapunov exponents were found to be positive in all case of the initial cutting conditions such as initial speed, feed rate and depth of cut. The initial cutting speed appears however to have the most significant impact on tool life. In particular, the mathematical model was successfully applied to the case of machining TiMMCs. It was clearly shown that changing the initial cutting speed by 20 m/min for the first two seconds of machining instead of keeping it constant at 60 m/min during the whole cutting process leads to an increase in the tool life (up to 24%).


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