High Precise Milling Process by cBN End Mills

2012 ◽  
Vol 6 (4) ◽  
pp. 542-545 ◽  
Author(s):  
Katsumi Naganuma ◽  
◽  
Masato Mori
Keyword(s):  
Research And Development ◽  
Tool Life ◽  
Small Diameter ◽  
Milling Process ◽  
Machining Accuracy ◽  
End Mill ◽  
Hard Materials ◽  
Machining Quality ◽  
Machining Test ◽  
End Mills

Molding technology is one way of producing the micro-precision parts required by various industries. To Advance this molding technology, various elemental technologies related to materials, construction and machiningmethods are evolving together. One of these elemental technologies is milling by end mill. Further research and development of end mill is underway in response to improvement and requirement of molding technologies. There are various demands for end mills such as improvement of tool life and stable machining quality. Here we report the small diameter cBN end mill, developed as a tool to provide with stable machining accuracy with long tool life for high hard materials. We report the investigations and characteristics at the time of development and show the machining test.

Monitoring of End-Mill Behavior with Its Projection Image

2006 ◽  
Vol 315-316 ◽  
pp. 474-480
Author(s):  
Dun Wen Zuo ◽  
Yoshihiro Kawano
Keyword(s):  
High Speed ◽  
Small Diameter ◽  
Milling Process ◽  
Measuring System ◽  
End Mill ◽  
Static State ◽  
High Speed Cutting ◽  
Projection Image ◽  
Image Width ◽  
End Mills

End mills with small diameter have found their wide application with the development of high-speed cutting. It becomes more and more important to develop effective methods to monitor and control the milling process with small end mills. In this paper, a measuring system of projection image for small end mills is introduced, and the application of the projection image to monitor the behavior of the end mill is discussed. It is found that for static state of the end mill, the measurement accuracy can be easily controlled within 1 μm. When the end mill rotates, it is not so difficult to control the accuracy within 3 μm. By using of the change in image width, the radial wear of end mill can be predicted. On the other hand, if the centre shift of the image is pre-measured, the deflection of the end mill during cutting can be predicted.

Research on Tool Wear Form in Micro Turn-Milling Process

2012 ◽  
Vol 184-185 ◽  
pp. 663-667 ◽  
Author(s):  
Lin Hui Zhao ◽  
Jian Cheng Zhang ◽  
Wei Su
Keyword(s):  
Tool Wear ◽  
Small Diameter ◽  
Milling Process ◽  
Milling Tool ◽  
Key Factor ◽  
Part Surface ◽  
End Mills ◽  
Series Of Experiments ◽  
Turn Milling ◽  
Wear Condition

In micro machining, turn-milling tool wear is a key factor for part surface quality. This paper carries on experiments on end mills wear in micro turn-milling machining, aiming to research the wear form and provide some reference data for developing wear standard of small diameter end mills. To measure wear condition of end mills, machine vision technique is utilized. This paper designs and sets up an online end mill wear measurement system for a micro turn-milling process center. With a series of experiments on small diameter end mills, wear conditions of different cutting positions are researched. Based on analysis of experiment data, wear characteristics and wear rule for micro turn-milling process are summarized in this paper.

Study on Machining Accuracy in Micro-Endmilling

2012 ◽  
Vol 516 ◽  
pp. 349-354
Author(s):  
Mitsuyoshi Nomura ◽  
Bo Xiao Ma ◽  
Osamu Horiuchi ◽  
Takayuki Shibata ◽  
Yoshihiko Murakami ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Tool Life ◽  
Thermal Deformation ◽  
Machining Accuracy ◽  
Bending Fatigue ◽  
Burr Size ◽  
End Mills ◽  
Strength And Stiffness ◽  
Point Of Reference

Micro end mills, for example, smaller than 0.5 mm in diameter have low strength and stiffness. They are rather difficult to be re-sharpened by grinding. Therefore they are usually used until their breakage or are exchanged for a new one when the machining results lose quality. In the previous study [, tool life up to breakage was experimentally investigated under various feed rates and some useful information was obtained to predict tool life considering a sort of bending fatigue. For each experiment, a new tool was used to machine slots till it broke due to fatigue and/or wear. In this study, in order to measure tool life based upon another point of reference, the machining accuracies of the above slots were investigated. The main results obtained are as follows: (1) Slot depth first increased due to thermal deformation of the spindle and then decreased due to tool wear, (2) Slot width decreased as the tool wear increased, (3) Slot bottom corner radius increased as the tool wear increased, (4) Burr size increased as the tool wear increased, (5) Surface roughness of the slot bottom seemed to be influenced by feed rate, tool wear and chatter.

scholarly journals Design and Optimization of Variable Pitch End Mills Based on Dynamic Balance Accuracy

2021 ◽  
Author(s):  
Wanying Nie ◽  
Minli Zheng ◽  
Shicheng Xu ◽  
Yuexiu Liu ◽  
Haibin Yu
Keyword(s):  
High Speed ◽  
Dynamic Balance ◽  
Optimization Method ◽  
Relative Displacement ◽  
Milling Process ◽  
Structure Design ◽  
End Mill ◽  
Variable Pitch ◽  
Balance Accuracy ◽  
End Mills

Abstract Variable pitch end mills are widely used in the high-speed milling process due to having better vibration reduction properties. However, because of the unequal pitch angles and the asymmetrical structure of end mills, there are principle error, poor dynamic balance accuracy, and serious tool vibration problems in the milling process. In order to improve the dynamic balance accuracy of variable pitch end mills, the structure of the end mill is designed and optimized based on the minimum eccentricity criterion in this paper. Firstly, by analyzing the dynamic balance of variable pitch end mills, the relationship between it and eccentricity is defined, and the end section model and the centroid equation are developed through the structure design of end mills. Then, the optimization method of variable pitch end mills is analyzed, the eccentricity decreases from e0= 150um to e'0 = 3um based on this method. the structure of the end mill is optimized to meet the design criteria, which improves the balance accuracy level of end mills. Finally, through the modal analysis for the optimized structure of the variable pitch end mill, the maximum relative displacement in the mode is reduced by about 17%, it is verified that the optimized end mills have better dynamic performances, which is of great significance for alleviating the cutting vibration and improving the cutting stability.

Generalized Modeling of Milling Mechanics and Dynamics: Part I — Helical End Mills

1999 ◽  
Author(s):  
Serafettin Engin ◽  
Yusuf Altintas
Keyword(s):  
Cutting Forces ◽  
Chip Thickness ◽  
Milling Process ◽  
Cutting Edge ◽  
End Mill ◽  
Edge Point ◽  
Stability Lobes ◽  
End Mills ◽  
Helical Flute ◽  
Cutting Point

Abstract Variety of helical end mill geometry is used in industry. Helical cylindrical, helical ball, taper helical ball, bull nosed and special purpose end mills are widely used in aerospace, automotive and die machining industry. While the geometry of each cutter may be different, the mechanics and dynamics of the milling process at each cutting edge point are common. This paper presents a generalized mathematical model of most helical end mills used in industry. The end mill geometry is modeled by helical flutes wrapped around a parametric envelope. The coordinates of a cutting edge point along the parametric helical flute are mathematically expressed. The chip thickness at each cutting point is evaluated by using the true kinematics of milling including the structural vibrations of both cutter and workpiece. By integrating the process along each cutting edge, which is in contact with the workpiece, the cutting forces, vibrations, dimensional surface finish and chatter stability lobes for an arbitrary end mill can be predicted. The predicted and measured cutting forces, surface roughness and stability lobes for ball, helical tapered ball, and bull nosed end mills are provided to illustrate the viability of the proposed generalized end mill analysis.

An Innovative Machining Strategy for Efficient Peripheral Finishing of Hard Materials with Highly-Varied-Helix End Mill

2015 ◽  
Vol 9 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Atsushi Ito ◽  
◽  
Eiji Shamoto ◽  
Keyword(s):  
Helix Angle ◽  
Hardened Steel ◽  
Chatter Vibration ◽  
End Mill ◽  
Rough Machining ◽  
Regenerative Chatter ◽  
Hard Materials ◽  
End Mills ◽  
Low Stiffness ◽  
Low Radial Immersion

Grinding is usually applied to the peripheral finishing of hardened steel since the high specific cutting force and low stiffness of slender end mills often causes chatter vibration. On the other hand, varied-helix end mills have suppressed regenerative chatter vibration successfully in the rough machining of flexible workpieces. In this research, varied-helix end mills are applied to the extremely low radial immersion finishing of hardened steel, and the validity of this application is discussed and verified experimentally in terms of suppression of regenerative chatter vibration. A special varied-helix end mill with an extremely large helix angle difference is developed for this new application, and its performance is compared to that of an ordinarily-varied-helix end mill for the low-radial-immersion peripheral finishing of hard materials.

scholarly journals High-Efficiency Milling of Steam Turbine Blade

2016 ◽  
Vol 10 (6) ◽  
pp. 993-999 ◽  
Author(s):  
Xin Yuan ◽  
◽  
Takanori Yazawa ◽  
Hideo Ito ◽  
Tatsuki Otsubo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Steam Turbine ◽  
Turbine Blade ◽  
High Efficiency ◽  
Small Diameter ◽  
Surface Profile ◽  
End Mill ◽  
End Mills ◽  
Steam Turbine Blade

Conventional methods often use ball end mills with a small diameter to finish machining of a steam turbine blade to satisfy accuracy requirements by using a small pick feed value. Thus, the cutting length increases, resulting in increased wear and a lower milling efficiency. Therefore, a new method using a tilt-taper end mill is proposed. This paper presents the validity of the proposed method used for milling planes by comparing the ball and square end mills through tool wear experiments. Factors including removal degree, surface roughness, tool wear, and machined surfaces are investigated with respect to the plane model. The experimental results show that tilt end mill can retard the tool wear remarkably to obtain a steady surface profile, and the maximum surface roughness value, using the tilt-taper end mill, is less than 6μm until process completion.

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