scholarly journals Geometric Analysis of Undeformed Chip Thickness in Ball-Nosed End Milling

2004 ◽  
Vol 47 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Hisanobu TERAI ◽  
Minghui HAO ◽  
Koichi KIKKAWA ◽  
Yoshio MIZUGAKI
Keyword(s):  
End Milling ◽  
Geometric Analysis ◽  
Chip Thickness ◽  
Undeformed Chip Thickness

An Approach to Modeling Cutting Forces in Five-Axis Ball-End Milling of Curved Geometries Based on Tool Motion Analysis

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Guo Dongming ◽  
Ren Fei ◽  
Sun Yuwen
Keyword(s):  
Motion Analysis ◽  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Axis Orientation ◽  
Undeformed Chip Thickness ◽  
Ball End Milling ◽  
Tool Motion ◽  
Five Axis

The prediction of five-axis ball-end milling forces is quite a challenge due to difficulties of determining the underformed chip thickness and engaged cutting edge. To solve these concerns, this paper presents a new mechanistic model of cutting forces based on tool motion analysis. In the model, for undeformed chip thickness determination, an analytical model is first established to describe the sweep surface of cutting edge during the five-axis ball-end milling process of curved geometries. The undeformed chip thickness is then calculated according to the real kinematic trajectory of cutting edges under continuous change of the cutter axis orientation. A Z-map method is used to verify the engaged cutting edge and cutting coefficients are subsequently calibrated. The mechanistic method is applied to predict the cutting force. Validation tests are conducted under different cutter postures and cutting conditions. The comparison between predicted and measured values demonstrates the applicability of the proposed prediction model of cutting forces.

Investigation of the size effect on burr formation in two-dimensional vibration-assisted micro end milling

2011 ◽  
Vol 225 (11) ◽  
pp. 2032-2039 ◽  
Author(s):  
H Ding ◽  
S-J Chen ◽  
R Ibrahim ◽  
K Cheng
Keyword(s):  
Tool Wear ◽  
Size Effect ◽  
End Milling ◽  
Chip Thickness ◽  
Integrated Model ◽  
Burr Formation ◽  
Two Dimensional ◽  
Undeformed Chip Thickness ◽  
Cutting Edge Radius ◽  
Micro End Milling

In precision and micro cutting processes, the tool cutting edge radius is generally quite large compared to the undeformed chip thickness, which can cause ploughing/rubbing between the tool and the workpiece and thus affect surface finish, tool wear, and burr formation. This paper investigates the effect of the size effect on top burr formation in two-dimensional vibration-assisted micro end milling (2D VAMEM). This is achieved by studying the effects of the ratio of undeformed chip thickness to the cutting edge radius, and the ratio of the time when the undeformed chip thickness is less than the minimum chip thickness to the total cutting time on top burr formation, using a model that integrates the chip thickness model of the 2D VAMEM and the minimum chip thickness prediction model. The corresponding experiments are carried out to verify the integrated model. It is found that feed per tooth has a significant effect on the height of the top burr, and the use of vibration-assisted cutting in micro end milling can minimize the size effect and improve the cutting performance, thereby reducing the height of the top burr. In addition, selecting suitable vibration parameters can significantly decrease the height of the top burr. The integrated model can be used to optimize the machining parameters to reduce burr size and further study the size effect on cutting force, surface roughness, and tool wear in 2D VAMEM.

scholarly journals Temperature Distribution of Micro Milling Process due to Uncut Chip Thickness

2014 ◽  
Vol 939 ◽  
pp. 214-221 ◽  
Author(s):  
B.T.H.T. Baharudin ◽  
Kooi Pin Ng ◽  
S. Sulaiman ◽  
R. Samin ◽  
M.S Ismail
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Model Validation ◽  
End Milling ◽  
Chip Thickness ◽  
Milling Process ◽  
Micro Milling ◽  
Work Piece ◽  
Workpiece Material ◽  
Undeformed Chip Thickness

A simplified model for micro milling process is presented, as well as results on temperature on tool and work piece. The purpose is to investigate on finite element modelling of two flute micro end milling process of titanium alloy, Ti6Al4V with prediction of temperature distribution. ABAQUS/Explicit has been chosen as solver for the analysis. A thermo-mechanical analysis was performed. First model was created by selecting medium carbon steel, AISI1045, as workpiece material for model validation purpose. Second model was created by modifying the workpiece material from AISI1045 to Ti6Al4V. The model consists of two parts which are tungsten carbide micro tool and workpiece. Johnson-Cook law model has been applied as material constitutive properties for both materials due to its severe plastic deformation occur during machining. Prediction on forces was obtained during the analysis. Model validation was done by comparing results published by Woon et al. in 2008. The results showed a good agreement in cutting force. Once this was proved, the same model was then modified to simulate finite element analysis in micro milling of Ti6Al4V. Prediction of temperature distribution of micro end mill of Ti6Al4V was done in relation of different undeformed chip thickness. The findings showed that temperature increases as undeformed chip thickness increases. Temperature distribution of Ti6Al4V and AISI1045 under same machining conditions was compared. Results showed that the highest temperature was concentrated at tool edge for Ti6Al4V.

Micro Flat End Milling Simulation Model With Instantaneous Plowing Area Prediction

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.

Mechanistic Modeling of the Ball End Milling Process for Multi-Axis Machining of Free-Form Surfaces

2000 ◽  
Vol 123 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Rixin Zhu ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor
Keyword(s):  
End Milling ◽  
Chip Thickness ◽  
Mechanistic Modeling ◽  
Free Form ◽  
Surface Geometry ◽  
Workpiece Surface ◽  
Ball End Milling ◽  
Modeling Approach ◽  
Free Form Surfaces ◽  
Cutting Point

A mechanistic modeling approach to predicting cutting forces is developed for multi-axis ball end milling of free-form surfaces. The workpiece surface is represented by discretized point vectors. The modeling approach employs the cutting edge profile in either analytical or measured form. The engaged cut geometry is determined by classification of the elemental cutting point positions with respect to the workpiece surface. The chip load model determines the undeformed chip thickness distribution along the cutting edges with consideration of various process faults. Given a 5-axis tool path in a cutter location file, shape driving profiles are generated and piecewise ruled surfaces are used to construct the tool swept envelope. The tool swept envelope is then used to update the workpiece surface geometry employing the Z-map method. A series of 3-axis and 5-axis surface machining tests on Ti6A14V were conducted to validate the model. The model shows good computational efficiency, and the force predictions are found in good agreement with the measured data.

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