scholarly journals Influence of dynamic geometric parameters on multi-axis machining processes

DYNA ◽  
2020 ◽  
Vol 87 (215) ◽  
pp. 214-220
Author(s):  
Andrés Felipe Cifuentes Gómez ◽  
Ernesto Cordoba Nieto
Keyword(s):  
Fourth Order ◽  
End Milling ◽  
Simulation Models ◽  
Angular Speed ◽  
Machining Processes ◽  
Lead Angle ◽  
Factorial Model ◽  
Geometric Factors ◽  
Milling Tool ◽  
Flat End Milling

By means of experimental, geometric and simulation models, roughness values of third and fourth order deviations are determined. The simulation environment is developed from the integration and simulated verification (ISV) in software NX 11 and the geometric approximations are validated through the analysis confocal microscopy.An experiment design is carried out to determine the influence of the dynamic geometric factors: transverse feed (Ae), lead angle and tilt angle, with a flat end milling tool with 1 mm diameter. In the experiment a 3k factorial model is presented to specify the factor with the greatest influence on the roughness. As a result, an optimum (minimum) roughness value is obtained. The lead angle has a moderate influence. Fourth order deviations are associated with the feed per tooth, with a constant angular speed of 5,000 rpm

High-Performance-Fräsbearbeitung von Graphitelektroden/High-Performance-milling of graphite electrodes – Potentials of monolithic ceramic end milling tool

2020 ◽  
Vol 110 (11-12) ◽  
pp. 790-795
Author(s):  
Eckhart Uhlmann ◽  
Julian Polte ◽  
Christoph Hein ◽  
Christian Jahnke ◽  
Mitchel Polte ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
High Performance ◽  
Electrical Discharge Machining ◽  
End Milling ◽  
Life Time ◽  
Machining Processes ◽  
Graphite Electrodes ◽  
New Approach ◽  
Milling Tool ◽  
Milling Tools

Mittels Fräsen gefertigte Formelektroden aus Feinkorngraphit sind für die Funkenerosion essentiell. Die spezifischen Werkstoffeigenschaften des Graphits resultieren in einer hervorragenden Zerspanbarkeit mit hohen Zeitspanvolumina QW und einer effizienten Anwendung in der Funkenerosion. Allerdings sind die Standzeiten TSt der Fräswerkzeuge durch einen ausgeprägten Werkzeugverschleiß stark limitiert. Die Verringerung des Werkzeugverschleißes stellt somit ein Potenzial für weitere Effizienzsteigerungen dar. Eine Perspektive bietet der Einsatz vollkeramischer Fräswerkzeuge. Milled graphite electrodes are essential for electrical discharge machining processes. The properties of the graphite allow high material removal rates QW and an effective application in electrical discharge machining. The life time TSt of the milling tools is limited by an extended wear at the same time. For this purpose, monolithic ceramic end milling tools are a promising new approach.

scholarly journals An Experimental Evaluation of Particle Impact Dampers Applied on the Tool for Milling of Hardened Steel Complex Surface

2021 ◽  
Author(s):  
Victor Rossi Saciotto ◽  
Anselmo Eduardo Diniz
Keyword(s):  
Complex Geometry ◽  
End Milling ◽  
Removal Rate ◽  
Complex Surface ◽  
Momentum Exchange ◽  
Machining Processes ◽  
Milling Tool ◽  
Highly Nonlinear ◽  
The Impact ◽  
Finishing Tool

Abstract In the manufacturing of dies and molds, vibrations may represent serious problems, since the finishing tool used is usually slender (high Length / Diameter ratio) in order to machine deep cavities with complex geometry, typical of these products. Vibration is an undesirable phenomenon in any machining operation as it can lead to poor surface finish, lower material removal rate and increased tool wear. The use of impact dampers in the tool has proven to be an effective method for reducing vibration in machining processes. Damping occurs through energy dissipation and linear momentum exchange during intermittent collisions between the main structure (in this case the milling tool) and a free mass (spheres or cylinders placed within a tool cavity). Although efficient, these types of dampers are highly nonlinear. Thus, the aim of this work is to analyze the effect of different materials and geometries (steel spheres, tungsten spheres and steel cylinders) acting as impact dampers inside a ball nose end milling tool. To do so, milling of a convex D6 steel surface was performed, comparing commercial tool holders with dampened ones. The results showed that the tools with impact dampers generated lower values of roughness in the workpiece (around 30% of the value observed in the conventional steel tool holder for the case of steel cylinders and around 40% for both spheres) and presented lower levels of vibration when compared to the same tool without the impact damper, mainly in the machining of workpiece regions where radial and tangential forces are predominant. The tool which used tungsten spheres generated roughness surfaces similar to those obtained with steel spheres, while the tool that used steel cylinders only generated lower roughness in the regions where the axial force component is not predominant, which shows that their performance is highly dependent on the resulting force direction.

Prediction of Burr Formation in Fabricating MEMS Components by Micro End Milling

2009 ◽  
Vol 74 ◽  
pp. 247-250 ◽  
Author(s):  
Mohammad Yeakub Ali ◽  
Mohd Aliff Omar ◽  
Khairul Irman Othman ◽  
Wayne N.P. Hung
Keyword(s):  
End Milling ◽  
Cutting Speed ◽  
304 Stainless Steel ◽  
Burr Formation ◽  
Aisi 304 ◽  
Burr Height ◽  
Milling Parameters ◽  
Milling Tool ◽  
Micro End Milling ◽  
Chip Load

This paper discusses burr formation in micromilling of AISI 304 stainless steel. Chip load, cutting speed and the application of coolant were chosen as the milling parameters. Experiments were conducted using 500 µm diameter tungsten carbide end milling tool. Milling parameters and measured burr height values were analyzed and statistical models were developed for the estimation of burr height. The models showed that the chip load and cutting speed both have direct and interactive contribution to burr formation. When micromachining without coolant, the burr height increases about 40% compared to that of machining with coolant. The optimized values of chip load and cutting speed were found to be 1 µm/tooth and 78 mms-1 respectively. The predicted burr heights were 5-7% larger than that of measured values.

scholarly journals Experimental and Numerical Analysis of High-Speed Internally Cooled Milling

CONVERTER ◽  
2021 ◽  
pp. 748-756
Author(s):  
Ningxia Yin Et al.
Keyword(s):  
High Speed ◽  
End Milling ◽  
Double Helix ◽  
Channel Structure ◽  
Dynamics Simulation ◽  
Thermal Dissipation ◽  
Machined Surface ◽  
Milling Tool ◽  
Internally Cooled ◽  
Cooling Technology

Advanced cooling technology is a crucial measure of thermal dissipation for high-speed end-milling. In order to get an appropriate cooling technology and decrease the negative effects of traditional wet cutting, internally cooled cutting has been paid more and more attention. Because of interrupted cutting and uneven force, there was few application and investigation on internally cooled end-milling. In the paper, the effect of the end-milling tool with different internally cooled channel structure has been researched by experiment and theoretical analysis. The experimental results indicate that the end-milling tool with double helix channels carried out best machined surface quality. And the experiment result was also been analyzed and explained by computational fluid dynamics simulation, which provides a basis for the applying of the high-speed internally cooled end-milling tool.

Experimental Investigation of the Effect of the Machine Kinematic Behavior on the Surface Topography and Roughness in High Speed Ball end Milling of the AISI4142 Steel

2021 ◽  
Author(s):  
Sai Lotfi ◽  
Belguith Rami ◽  
Baili Maher ◽  
Desseins Gilles ◽  
Bouzid Wassila
Keyword(s):  
Surface Topography ◽  
High Speed ◽  
End Milling ◽  
Experimental Investigations ◽  
Ball End Milling ◽  
Tool Paths ◽  
Stationary Zone ◽  
Machining Errors ◽  
Kinematic Behavior ◽  
Milling Tool

Abstract The analysis of the surface topography in ball end milling is an objective studied by many researchers, several methods were used and many combinations of cutting conditions and machining errors are considered. In the milling tool paths the trajectories presents a points of changing direction where the tool decelerates before and accelerates after respecting the velocity profiles of the machine. In this paper, we propose experimental investigations of the effect of the kinematic behavior of the machine tool on the surface quality. A poor topography and roughness are remarked on the deceleration and the acceleration zones compared to the stationary zone.

scholarly journals Modified Mechanistic Model Based on Gaussian Process Adjusting Technique for Cutting Force Prediction in Micro-End Milling

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Xiaoping Liao ◽  
Zhenkun Zhang ◽  
Kai Chen ◽  
Kang Li ◽  
Junyan Ma ◽  
...  
Keyword(s):  
Gaussian Process ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Mechanistic Model ◽  
Machining Process ◽  
Mechanistic Models ◽  
Machining Processes ◽  
Model Based ◽  
Micro End Milling

Micro-end milling is in common use of machining micro- and mesoscale products and is superior to other micro-machining processes in the manufacture of complex structures. Cutting force is the most direct factor reflecting the processing state, the change of which is related to the workpiece surface quality, tool wear and machine vibration, and so on, which indicates that it is important to analyze and predict cutting forces during machining process. In such problems, mechanistic models are frequently used for predicting machining forces and studying the effects of various process variables. However, these mechanistic models are derived based on various engineering assumptions and approximations (such as the slip-line field theory). As a result, the mechanistic models are generally less accurate. To accurately predict cutting forces, the paper proposes two modified mechanistic models, modified mechanistic models I and II. The modified mechanistic models are the integration of mathematical model based on Gaussian process (GP) adjustment model and mechanical model. Two different models have been validated on micro-end-milling experimental measurement. The mean absolute percentage errors of models I and II are 7.76% and 6.73%, respectively, while the original mechanistic model’s is 15.14%. It is obvious that the modified models are in better agreement with experiment. And model II performs better between the two modified mechanistic models.

A HIGHER FIDELITY MODELING OF THE CUTTING EDGE OF BALL-END MILLING TOOL

2011 ◽  
Vol 10 (01) ◽  
pp. 101-108 ◽  
Author(s):  
XIULIN SUI ◽  
IMRE HORVATH ◽  
JIATAI ZHANG ◽  
PING ZHANG
Keyword(s):  
End Milling ◽  
Milling Process ◽  
Cutting Edge ◽  
Ball End Milling ◽  
Machining Conditions ◽  
Milling Tool ◽  
Efficient Planning ◽  
Pilot Implementation ◽  
Physical Changes ◽  
Milling Forces

Ball-end milling tools have been widely used in machining of complex freeform surfaces. The precision and efficiency of ball-end milling process can be improved by an accurate modeling of the tools, the tools' paths and the machining conditions. However, only rough geometric models have been applied so far, which do not consider the machining conditions and the physical changes. To achieve the best results, an accurate modeling of the cutting edge and the physical behavior of the entire cutter is needed. This paper proposes an articulated model that enumerates both the geometric characteristics and the physical effects acting on the cutting edge-segment of a ball-end milling cutter. The model considers the deformations caused by the milling forces, vibration, spindle eccentricity, together with thermal deformation and wear of the cutter. The mathematical description of the behavior has been transferred into a computational model. The pilot implementation has been tested in a practical application. The first findings show that the proposed theoretical model and implementation provide sufficiently precise information about the behavior of the cutter in virtual simulations; hence it can be the basis of a fully fledged and more efficient planning of milling processes.

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