Robust chatter stability in micro-milling operations

CIRP Annals ◽  
2010 ◽  
Vol 59 (1) ◽  
pp. 391-394 ◽  
Author(s):  
S.S. Park ◽  
R. Rahnama
Keyword(s):  
Micro Milling ◽  
Chatter Stability ◽  
Milling Operations

Chatter Stability in Micro Milling Processes Considering Ploughing and Process Damping Effects

2009 ◽  
Author(s):  
Ramin Rahnama ◽  
Mozhdeh Sajjadi ◽  
Simon S. Park
Keyword(s):  
Time Domain ◽  
Chip Thickness ◽  
Experimental Tests ◽  
Micro Milling ◽  
Chatter Stability ◽  
Workpiece Material ◽  
Process Damping ◽  
Milling Operations ◽  
Milling Operation ◽  
Cutting Mechanisms

Micro milling operations utilize miniature tools to remove workpiece material, in order to create the desired 3D miniature components. One of the challenges in a micro milling operation is the unstable phenomenon called regenerative chatter. The occurrence of chatter in the micro domain, as in macro machining, is detrimental to part finishes and significantly reduces the longevity of tools. There are two different cutting mechanisms in micro milling operations, which are determined by the critical chip thickness. When the chip thickness is less than the critical chip thickness, no chip forms and ploughing occurs; whereas, when the chip thickness is greater than the critical chip thickness, a chip forms and shearing cutting happens. During each rotation of the tool, the cutting mechanisms switch from ploughing to shearing and vice versa. This paper introduces a time domain chatter model to investigate the effects of the ploughing and shearing mechanisms on stability. The model also considers the effects of process damping in micro milling, especially at low spindle speeds. Several experimental tests have been performed to validate the model.

Effects of Ion Beam Milling on Surface Topography

1973 ◽  
Vol 31 ◽  
pp. 84-85
Author(s):  
P.G. Pawar ◽  
P. Duhamel ◽  
G.W. Monk
Keyword(s):  
Surface Topography ◽  
Ion Beam ◽  
Solid Material ◽  
Beam Current ◽  
Atomic Mass ◽  
Micro Milling ◽  
Ion Milling ◽  
Controlled Atmospheres ◽  
Milling Operations ◽  
Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

scholarly journals An Efficient Third-Order Full-Discretization Method for Prediction of Regenerative Chatter Stability in Milling

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Chao Huang ◽  
Wen-An Yang ◽  
Xulin Cai ◽  
Weichao Liu ◽  
YouPeng You
Keyword(s):  
Metal Removal ◽  
Removal Rate ◽  
Discretization Method ◽  
Chatter Stability ◽  
Computationally Efficient ◽  
Third Order ◽  
Regenerative Chatter ◽  
Full Discretization ◽  
Milling Operations ◽  
Comparison Results

The prediction of regenerative chatter stability has long been recognized as an important issue of concern in the field of machining community because it limits metal removal rate below the machine’s capacity and hence reduces the productivity of the machine. Various full-discretization methods have been designed for predicting regenerative chatter stability. The main problem of such methods is that they can predict the regenerative chatter stability but do not efficiently determine stability lobe diagrams (SLDs). Using third-order Newton interpolation and third-order Hermite interpolation techniques, this study proposes a straightforward and effective third-order full-discretization method (called NI-HI-3rdFDM) to predict the regenerative chatter stability in milling operations. Experimental results using simulation show that the proposed NI-HI-3rdFDM can not only efficiently predict the regenerative chatter stability but also accurately identify the SLD. The comparison results also indicate that the proposed NI-HI-3rdFDM is very much more accurate than that of other existing methods for predicting the regenerative chatter stability in milling operations. A demonstrative experimental verification is provided to illustrate the usage of the proposed NI-HI-3rdFDM to regenerative chatter stability prediction. The feature of accurate computing makes the proposed NI-HI-3rdFDM more adaptable to a dynamic milling scenario, in which a computationally efficient and accurate chatter stability method is required.

Chatter Stability Model of Micro-Milling With Process Damping

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Xiaoliang Jin ◽  
Yusuf Altintas
Keyword(s):  
Finite Element ◽  
Cutting Speed ◽  
Rake Angle ◽  
Micro Milling ◽  
Piezo Actuator ◽  
Chatter Stability ◽  
Line Field ◽  
Process Damping ◽  
Aisi 1045 Steel ◽  
1045 Steel

This paper presents the prediction of cutting forces and chatter stability of micro-milling operations from the material's constitutive flow stress and structural dynamics of the micro-end mill. The cutting force coefficients are identified either using previously presented slip-line field or finite element methods by considering the effects of chip size, cutting edge radius, rake angle and cutting speed. The process damping caused by the plowing of round edge is modeled by finite element method. The frequency response function of the fragile micro-mill is measured through specially devised piezo actuator mechanism. Dynamic model of micro-milling with the velocity dependent process damping mechanism is presented, and the chatter stability is predicted in frequency domain. The proposed models have been experimentally verified in micro-milling of AISI 1045 steel.

scholarly journals Micro-Milling Process of Metals: A Comparison between Femtosecond Laser and EDM Techniques

2021 ◽  
Vol 5 (4) ◽  
pp. 125
Author(s):  
Luigi Calabrese ◽  
Martina Azzolini ◽  
Federico Bassi ◽  
Enrico Gallus ◽  
Sara Bocchi ◽  
...  
Keyword(s):  
Removal Rate ◽  
Milling Process ◽  
Micro Milling ◽  
Electric Discharge Machining ◽  
Workpiece Material ◽  
Electrically Conductive ◽  
Milling Operations ◽  
Micro Channels ◽  
Micro Pillars

Nowadays, micro-machining techniques are commonly used in several industrial fields, such as automotive, aerospace and medical. Different technologies are available, and the choice must be made considering many factors, such as the type of machining, the number of lots and the required accuracy specifications in terms of geometrical tolerances and surface finish. Lasers and electric discharge machining (EDM) are widely used to produce micro-components and are similarly unconventional thermal technologies. In general, a laser is particularly appreciated by the industry for the excellent machining speeds and for the possibility to machine essentially any type of materials. EDM, on the other hand, has a poor material removal rate (MRR) but can produce microparts on only electrically conductive workpieces, reaching high geometrical accuracy and realizing steep walls. The most common micro-application for both the technologies is drilling but they can make also milling operations. In this work, a comparison of femto-laser and EDM technologies was made focusing on micro-milling. Two features were selected to make the comparison: micro-channels and micro-pillars. The depth was varied on two levels for both features. As workpiece material, aluminum, stainless steel and titanium alloy were tested. Data regarding the process performance and the geometrical characteristics of the features were analyzed. The results obtained with the two technologies were compared. This work improves the knowledge of the micro-manufacturing processes and can help in the characterization of their capabilities.

Command shaping control for micro-milling operations

2011 ◽  
Vol 9 (6) ◽  
pp. 1136-1145 ◽  
Author(s):  
Joel Fortgang ◽  
William Singhose ◽  
Juan de Juanes Márquez ◽  
Jesus Perez
Keyword(s):  
Micro Milling ◽  
Command Shaping ◽  
Milling Operations

Simulation Model for Micro-Milling Operations and Surface Generation

2011 ◽  
Vol 223 ◽  
pp. 849-858 ◽  
Author(s):  
Iwona Piotrowska Kurczewski ◽  
Jost Vehmeyer
Keyword(s):  
Quality Parameters ◽  
Micro Milling ◽  
Surface Generation ◽  
Generation Model ◽  
Time Step ◽  
Cross Sectional ◽  
Production Chain ◽  
Milling Operations ◽  
Full Production ◽  
Workpiece Interaction

In this paper we propose a new mathematical model for micro milling operations. To achieve the desired quality of the final product or the desired structure on the product's surface the process kinematics as well as tool-workpiece interaction are considered. The presented model takes into account the relative motion between tool and workpiece. We consider the input infeed rate which is reduced by the elastic deflection of the tool due to the cutting forces appearing during the process. The tool wear and surface texture depend on the cutting force; therefore the analysis of the forces plays an important role in characterizing the cutting process. Moreover, the analyzing these forces during the simulation we can calculate the effective cross-sectional area of the cut in each time step of the process. This gives us a forward model for the full production chain. This model is extended in order to include a surface generation model as well as quality parameters for the resulting micro-milling surface.

Micro Milling on Thin Wire

2017 ◽  
Vol 749 ◽  
pp. 81-86
Author(s):  
Masaki Serizawa ◽  
Takashi Matsumura
Keyword(s):  
Cutting Forces ◽  
Micro Milling ◽  
End Mill ◽  
Thin Wires ◽  
Feed Direction ◽  
Surface Finishes ◽  
Milling Operations ◽  
Fine Surface ◽  
Clamping System ◽  
Scale Structures

Micro milling is discussed to fabricate micro-scale structures on titanium alloy thin wires. A machine tool was developed to conduct the milling operations with improving the clamping stiffness. A 0.3 mm diameter wire inserted into polyurethane tubes was clamped on an R-shaped groove on the machine table. The cutting tests were conducted with or without the polyurethane tube support. The machining shapes, the surface finishes and the cutting forces were measured to verify the effect of the polyurethane tube and machine table clamping system on stability in the cutting process. The groove direction is out of the feed direction of the end mill without the polyurethane tube support. The micro grooves are machined properly with a fine surface in the feed direction with the support. The cutting forces change periodically with the cutting thickness and the rotation of the cutter in milling. Non-symmetric grooves are also machined with the developed clamping system.

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