The determination of instantaneous uncut chip thickness for non-uniform helix angle tools with complex tool path in ultrasonic milling process

As a key factor, the accuracy of the instantaneous undeformed thickness model determines the force-predicting precision and further affects workpiece machining precision in the micro-milling process. The runout with five parameters affects the machining process more significantly compared with macro-milling. Furthermore, modern industry uses cutters with non-uniform pitch and helix angles more and more common for their excellent properties. In this article, an instantaneous undeformed thickness model is presented regarding cutter runout, variable pitch, and helix angles in the micro-milling process. The cutter edge with the cutter runout effect is modeled. Then, the intersecting ellipse between the plane vertical to the spindle axis and the cutter surface which is a cylinder can be gained. Based on this, the points, which are used to remove the material, on the ellipse as well as cutter edges are calculated. The true trochoid trajectory for each cutting point along the tool path is built. Finally, the instantaneous undeformed thickness values are computed using a numerical algorithm. In addition, this article analyzes runout parameters’ effects on the instantaneous undeformed thickness values. After that, helix and pitch angles’ effects on the instantaneous undeformed thickness are studied. Ultimately, the last section verifies the correctness and validity of the instantaneous undeformed thickness model based on the experiment conducted in the literature.

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An integral algorithm for instantaneous uncut chip thickness measuring in the milling process

Advances in Production Engineering & Management ◽

10.14743/apem2018.3.291 ◽

2018 ◽

Vol 13 (3) ◽

pp. 297-306

Author(s):

Y. Li ◽

Z.J. Yang ◽

C. Chen ◽

Y.X. Song ◽

J.J. Zhang ◽

...

Keyword(s):

Chip Thickness ◽

Milling Process ◽

Uncut Chip Thickness ◽

Instantaneous Uncut Chip Thickness

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Instantaneous Uncut Chip Thickness Model in End Milling Based on an Improved Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.764.399 ◽

2018 ◽

Vol 764 ◽

pp. 399-407

Author(s):

Yue Zhang ◽

Zhi Qiang Yu ◽

Tai Yong Wang

Keyword(s):

End Milling ◽

Chip Thickness ◽

Transcendental Equation ◽

Milling Process ◽

Force Model ◽

Uncut Chip Thickness ◽

Milling Force ◽

Milling Force Model ◽

Instantaneous Uncut Chip Thickness ◽

Taylor’S Series

The instantaneous uncut chip thickness is an important parameter in the study of milling force model. By analyzing the real tooth trajectory in milling process, accurate instantaneous uncut chip thickness can be obtained to solve the complex transcendental equation. Traditional chip thickness models always simplify the tooth trajectory to get approximate solution. A new instantaneous uncut chip thickness model is proposed in this paper. Based on real tooth trajectory of general end milling cutter, a Taylor's series is used to approximate the involved infinitesimal variable in the transcendental equation, which results in an explicit expression for practical application of the uncut chip thickness with higher accuracy compared to the traditional model.

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Micro Flat End Milling Simulation Model With Instantaneous Plowing Area Prediction

Journal of Micro and Nano-Manufacturing ◽

10.1115/1.4032757 ◽

2016 ◽

Vol 4 (2) ◽

Author(s):

Abdolreza Bayesteh ◽

Junghyuk Ko ◽

Martin Byung-Guk Jun

Keyword(s):

Feed Rate ◽

Tool Path ◽

End Milling ◽

Chip Thickness ◽

Depth Of Cut ◽

Uncut Chip Thickness ◽

Chip Area ◽

Edge Radius ◽

Wide Range ◽

Radial Depth

There is an increasing demand for product miniaturization and parts with features as low as few microns. Micromilling is one of the promising methods to fabricate miniature parts in a wide range of sectors including biomedical, electronic, and aerospace. Due to the large edge radius relative to uncut chip thickness, plowing is a dominant cutting mechanism in micromilling for low feed rates and has adverse effects on the surface quality, and thus, for a given tool path, it is important to be able to predict the amount of plowing. This paper presents a new method to calculate plowing volume for a given tool path in micromilling. For an incremental feed rate movement of a micro end mill along a given tool path, the uncut chip thickness at a given feed rate is determined, and based on the minimum chip thickness value compared to the uncut chip thickness, the areas of plowing and shearing are calculated. The workpiece is represented by a dual-Dexel model, and the simulation properties are initialized with real cutting parameters. During real-time simulation, the plowed volume is calculated using the algorithm developed. The simulated chip area results are qualitatively compared with measured resultant forces for verification of the model and using the model, effects of cutting conditions such as feed rate, edge radius, and radial depth of cut on the amount of shearing and plowing are investigated.

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FE analysis of the effects of process representations on the prediction of residual stresses and chip morphology in the down-milling of Ti6Al4V

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4051287 ◽

2021 ◽

pp. 1-50

Author(s):

Nejah Tounsi ◽

Tahany El-Wardany

Keyword(s):

Experimental Data ◽

Residual Stresses ◽

Orthogonal Cutting ◽

Chip Thickness ◽

Chip Morphology ◽

Milling Process ◽

Uncut Chip Thickness ◽

Orthogonal Machining ◽

Cutting Length ◽

Sequential Cuts

Abstract Part I of these two-part papers will investigate the effect of three FEM representations of the milling process on the prediction of chip morphology and residual stresses (RS), when down-milling small uncut chips with thickness in the micrometer range and finite cutting edge radius. They are: i) orthogonal cutting with the mean uncut chip thickness t, obtained by averaging the uncut chip thickness over the cutting length, ii) orthogonal cutting with variable t, which characterizes the down-milling process and which is imposed on a flat surface of the final workpiece, and iii) modelling the true kinematics of the down milling process. The appropriate constitutive model is identified through 2D FEM investigation of the effects of selected constitutive equations and failure models on the prediction of RS and chip morphology in the dry orthogonal machining of Ti6Al4V and comparison to experimental measurements. The chip morphology and RS prediction capability of these representations is assessed using the available set of experimental data. Models featuring variable chip thickness have revealed the transition from continuous chip formation to the rubbing mode and have improved the predictions of residual stresses. The use of sequential cuts is necessary to converge toward experimental data.

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Off-line error compensation in corner milling process

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405416666901 ◽

2016 ◽

Vol 232 (7) ◽

pp. 1172-1181 ◽

Cited By ~ 7

Author(s):

Caixu Yue ◽

Xianli Liu ◽

Yunpeng Ding ◽

Steven Y Liang

Keyword(s):

Cutting Force ◽

Error Compensation ◽

Tool Path ◽

Chip Thickness ◽

Milling Process ◽

Process Conditions ◽

Force Model ◽

Tool Deflection ◽

Profile Error ◽

Compensation Algorithm

Tool deflection induced by cutting force could result in dimensional inaccuracies or profile error in corner milling process. Error compensation has been proved to be an effective method to get accuracy component in milling process. This article presents a methodology to compensate profile errors by modifying tool path. The compensation effect strongly depends on accuracy of the cutting force model used. The mathematical expression of chip thickness is proposed based on the true track of cutting edge for corner milling process, which considers the effect of tool deflection. The deflection of tool is calculated by finite element method. Then, an off-line compensation algorithm for corner profile error is developed. Following the theoretical analysis, the effect of the error compensation algorithm is verified by experimental study. The outcome provides useful comprehension about selection of process conditions for corner milling process.

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Chip Thickness Analysis in Peripheral Milling of Curved Surfaces with Variable Curvature Considering Cutter Runout

Materials Science Forum ◽

10.4028/www.scientific.net/msf.697-698.75 ◽

2011 ◽

Vol 697-698 ◽

pp. 75-79 ◽

Cited By ~ 3

Author(s):

Y. Yang ◽

Min Wan ◽

Wei Hong Zhang ◽

Y. Li

Keyword(s):

Chip Thickness ◽

Current Approach ◽

The Novel ◽

Cutter Runout ◽

Peripheral Milling ◽

Uncut Chip Thickness ◽

Systematic Analysis ◽

Variable Curvature ◽

Proposed Model ◽

Instantaneous Uncut Chip Thickness

Analysis of instantaneous uncut chip thickness (IUCT) in peripheral milling of curved surface with variable curvature is nontrivial due to the combined influences of both process geometry and cutter runout. This paper gives a systematic analysis of IUCT including the effects of changing workpiece geometry and the cutter runout in peripheral milling. The prominent feature of this analysis procedure lies in that the novel equation for computing the IUCT is mathematically derived in detail. Numerical simulations are performed to study the effect of workpiece curvature and cutter runout on IUCT. The proposed model is validated by comparing the measured cutting forces with those predicted based on the IUCT which is obtained using the current approach.

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