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Wpływ mikrogeometrii krawędzi skrawającej na kształtowanie powierzchni frezem kulistym

Jemielniak Krzysztof

Mechanik

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2020

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R. 93, nr 10

14

PL

Kształtowanie powierzchni podczas obróbki skrawaniem jest wynikiem złożonego oddziaływania między krawędzią skrawającą i materiałem obrabianym, co sprawia, że rzeczywista topografia powierzchni różni się znacznie od teoretycznej. W artykule przedstawiono model takiej interakcji, pozwalający na wiarygodne przewidywanie topografii powierzchni frezowanej frezem kulistym.

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Modeling of cutter displacements during ball end milling of inclined surfaces

Wojciechowski S., Chwalczuk T., Twardowski P., Krolczyk G. M.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 4

798--805

EN

This work concentrates on the modeling of cutter's displacements during ball end milling with various surface inclinations. The cutter's displacements (vibrations) model including: tool's geometry, cutting conditions, surface inclination angle, run out and tool's deflections (induced by the cutting forces) was proposed. Subsequently, this model was validated empirically during the milling tests with various feed per tooth (fz), depth of cut (ap) and surface inclination angle (α) values. Experiments were carried out with the application of laser displacement sensor and force dynamometer. The research revealed that cutter's displacements are strongly affected by the cutter's run out and surface inclination. This observation is also confirmed by the developed model.

3

Surface texture analysis after ball end milling with various surface inclination of hardened steel

Wojciechowski S., Twardowski P., Wieczorowski M.

Metrology and Measurement Systems

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2014

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Vol. 21, nr 1

145--156

EN

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 α. 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 λ), 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 α = 0°) is unfavorable from the point of view of surface roughness, because in cutter’s axis the cutting speed νc ≈ 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 α ≠ 0°, because the cutting speed νc ≠ 0 on the full 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 α ≠ 0°, in comparison with those determined for plain cutting (α = 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.

4

Wpływ odchylenia freza o zakończeniu kulistym na energię usuwania materiału

Szafarczyk M.

Mechanik

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2013

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R. 86, nr 8-9

769

5

Investigation of surface integrity in high-speed ball end milling of cantilever shaped thin plate of Inconel 718

Bhopale N N, Pawade R S

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 2

616--622

EN

The paper addresses the effects of cutting speed and feed on the work piece deflection and surface integrity during milling of cantilever shaped Inconel 718 plate under different cutter orientations. The experiments were conducted on a CNC vertical milling machine using 10 mm diameter TiAlN coated solid carbide ball end milling cutter. Surface integrity is assessed in terms of micro hardness beneath the machined surface. The micro-hardness profile shows different patterns at various cutting parameters. It is observed that at large cutting speed as well as feeds, thicker work piece with larger work piece inclination shows higher micro hardness as compared to the other machining conditions.

6

Influence of workpiece inclination angle on the surface roughness in ball end milling of the titanium alloy Ti-6Al-4V

Daymi A., Boujelbene M., Linares J. M., Bayraktar E., Ben Amara A.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 35, nr 1

79-86

EN

Purpose: The aim of this work is to provide an in-depth understanding of the surface texture produced by various workpiece inclination angles using high speed finish ball end-milling of the titanium alloy Ti-6Al-4V. Design/methodology/approach: This paper presents an approach to develop a mathematical model of surface roughness in end-milling by the experimental design methodology. Machining variables such as cutting speed, feed and radial depth of cut, which are easily controllable, are considered in building the model. The influence of the workpiece inclination angle on the surface roughness of the machined workpiece was also investigated. Findings: According to the mathematical model, an increase in either the feed or the radial depth of cut increases the surface roughness, whilst an increase in cutting speed decreases it. The radial depth of cut ae is the most significant parameter in the model. Results analysis of the 2D/3D surface roughness parameters of the machined parts shows the improvement of the surface roughness quality when it is machined with a workpiece inclination angle of 25°. Research limitations/implications: As perspectives of this work, we can study the influence of the different machining strategies on the surface integrity of this titanium alloy, including the study of the residual stress. Practical implications: We propose to study the improvement of the surface quality of the orthopedic prostheses, which is an influencing parameter in their lifetime, by implementing the high speed cutting technique. The mathematical model of the surface roughness is a very important result of this work. In fact, it allows selecting the best cutting conditions to obtain a better workpiece surface quality. Originality/value: In this work, three dimensional surface roughness parameters were studied: the 3D surface topographies were obtained using a 3D measurement station and the mathematical model of Sa. The arithmetic mean deviation of the surface was established in order to minimize the experimental works and to have an idea about the surface roughness evolution as a function of cutting parameters.

7

Intelligent system for machining and optimization of 3D sculptured surfaces with ball-end milling

Milfelner M., Kopac J., Cus F., Zuperl U.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 14, nr 1-2

171--177

EN

Purpose: This paper describes about intelligent machining system which is applied in a high speed machining robot with on-line monitoring and optimization for ball-end milling process. Design/methodology/approach: Manufacturing of 3D sculptured surfaces on high speed machining robot involves a number of machining parameters and tool geometries. The system collects machining data and cutting parameters which are necessary for genetic algorithm optimization. Findings: An intelligent machining system is developed for the simulation and testing on the PC machine. It is based on a main PC computer, which is connected to the high speed machining robot main processor so that control and communication can be realized. The system collects the variables of the cutting process by means of sensors which are optimized with the genetic algorithms. Research limitations/implications: 3D sculptured milling covers a wide range of operations. In 3D metal cutting processes, cutting conditions have an influence on reducing the production cost and time and deciding the quality of a final product. Practical implications: Simulated results show that the proposed intelligent machining system is effective and efficient, and can be integrated into a real-time intelligent manufacturing system for solving complex machining optimization problems. Originality/value: The paper describes about intelligent machining system which can applied in intelligent manufacturing process.