Tool stiffness influence on the chosen physical parameters of the milling process

2012 ◽  
Vol 60 (3) ◽  
pp. 597-604 ◽  
Author(s):  
W. Zębala
Keyword(s):  
Titanium Alloy ◽  
Aluminium Alloy ◽  
Chip Formation ◽  
Cutting Forces ◽  
Contact Point ◽  
Milling Process ◽  
Cutting Process ◽  
Physical Parameters ◽  
Titanium Alloy Ti6al4v ◽  
The Impact

Abstract This article presents our own model researches, relating to the down milling process of Aluminium alloy (Al6061) and Titanium alloy (Ti6Al4V), with a tool made of sintered carbides. These investigations pay the special attention to the impact of the tool rigidity on the process of chip formation. The simulation calculations have been carried out for two cases of the cutting process: case 1 - assuming an ideally rigid construction of a milling cutter (length of tool does not impact its deflection under the cutting forces); case 2 - it is possible that the tool can be subjected to deflection under the cutting forces (length of a tool part is counted from the holder end to the contact point of a cutting edge with the machining material).

scholarly journals The influence of tool diameter on wear during milling of titanium alloy Ti6Al4V

Mechanik ◽  
2017 ◽  
Vol 90 (3) ◽  
pp. 198-200
Author(s):  
Józef Kuczmaszewski ◽  
Kazimierz Zaleski ◽  
Jakub Matuszak ◽  
Tomasz Pałka ◽  
Rafał Garwacki
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
Milling Process ◽  
Production Costs ◽  
High Durability ◽  
Titanium Alloy Ti6al4v ◽  
Wear Tool ◽  
Tool Diameter ◽  
The Impact ◽  
Large Coefficient

One of the main problems associated with machining of difficult-to-cut materials is tool wear. Tool wear may comprise a large proportion of production costs. Titanium alloys due to its properties – low thermal conductivity, high durability and a large coefficient of friction belong to difficult-to-cut materials. The paper presents the results of research on the impact of cutter diameter on tool wear during the milling process of titanium alloy Ti6Al4V.

scholarly journals Towards Dry Machining of Titanium-Based Alloys: A New Approach Using an Oxygen-Free Environment

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1161
Author(s):  
Hans Jürgen Maier ◽  
Sebastian Herbst ◽  
Berend Denkena ◽  
Marc-André Dittrich ◽  
Florian Schaper ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Wear Mechanism ◽  
Chip Formation ◽  
Cutting Forces ◽  
High Vacuum ◽  
Argon Atmosphere ◽  
Dry Machining ◽  
New Approach ◽  
Underlying Mechanisms ◽  
Free Environment

In the current study, the potential of dry machining of the titanium alloy Ti-6Al-4V with uncoated tungsten carbide solid endmills was explored. It is demonstrated that tribo-oxidation is the dominant wear mechanism, which can be suppressed by milling in an extreme high vacuum adequate (XHV) environment. The latter was realized by using a silane-doped argon atmosphere. In the XHV environment, titanium adhesion on the tool was substantially less pronounced as compared to reference machining experiments conducted in air. This goes hand in hand with lower cutting forces in the XHV environment and corresponding changes in chip formation. The underlying mechanisms and the ramifications with respect to application of this approach to dry machining of other metals are discussed.

Mechanism of Variable Helix Tools in Suppressing Chatter Using Process Damping for Machining Titanium Alloys at Low Cutting Speed

2013 ◽  
Vol 773-774 ◽  
pp. 370-376
Author(s):  
Muhammad Adib Shaharun ◽  
Ahmad Razlan Yusoff ◽  
Mohammad S. Reza
Keyword(s):  
Titanium Alloy ◽  
Cutting Speed ◽  
Milling Process ◽  
Cutting Process ◽  
Chatter Vibration ◽  
Process Damping ◽  
High Cutting Speed ◽  
Titanium Machining ◽  
Different Types ◽  
Variable Helix

Titanium is difficult-to-cut materials due to its poor machinability and thermal conductivity when machining at high cutting speed. To overcome this machining titanium alloy problem, this study in interaction between machining structural system and the cutting process are very important. One of the main problems in the cutting process is chatter vibration. Due to chatter problem, the mechanism to suppress chatter named, process damping is a useful method can be manipulated to improve the limited productivity of titanium machining at low speed machining in milling process. In the present study, experiment are conducted to evaluate and study the process damping mechanism in milling using different types of variable tools geometries. These tools are variable he-lix/uniform pitch, variable pitch/uniform helix and variable helix and pitch and uniform helix/pitch. The result showed that the variable helix and pitch tools is very significantly improve process damping performance in machining titanium alloy compare to traditional of regular tools and other irregular tools.

scholarly journals Analytical modelling of cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V

2014 ◽  
Vol 229 (6) ◽  
pp. 1122-1133 ◽  
Author(s):  
Yun Chen ◽  
Huaizhong Li ◽  
Jun Wang
Keyword(s):  
Titanium Alloy ◽  
Cutting Forces ◽  
Chemical Reactivity ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Analytical Modelling ◽  
Shear Instability ◽  
Published Data ◽  
Machining Processes ◽  
Titanium Alloy Ti6al4v

Titanium and its alloys are difficult to machine due to their high chemical reactivity with tool materials and low thermal conductivity. Chip segmentation caused by the thermoplastic instability is always observed in titanium machining processes, which leads to varied cutting forces and chip thickness, etc. This paper presents an analytical modelling approach for cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V. The catastrophic shear instability in the primary shear plane is assumed as a semi-static process. An analytical approach is used to evaluate chip thicknesses and forces in the near-orthogonal cutting process. The shear flow stress of the material is modelled by using the Johnson–Cook constitutive material law where the strain hardening, strain rate sensitivity and thermal softening behaviours are coupled. The thermal equations with non-uniform heat partitions along the tool–chip interface are solved by a finite difference method. The model prediction is verified with experimental data, where a good agreement in terms of the average cutting forces and chip thickness is shown. A comparison of the predicted temperatures with published data obtained by using the finite element method is also presented.

3D FE-Based Modelling and Simulation of the Micro Milling Process

2012 ◽  
Vol 516 ◽  
pp. 634-639 ◽  
Author(s):  
Tao Wu ◽  
Kai Cheng
Keyword(s):  
Chip Formation ◽  
Cutting Forces ◽  
Reasonable Agreement ◽  
Large Deformations ◽  
Helix Angle ◽  
Milling Process ◽  
Modelling And Simulation ◽  
Micro Milling ◽  
3D Finite Element ◽  
Milling Performance

Modelling and simulation of the micro milling process has the potential to improve tool design and optimize cutting conditions. This paper presents a novel and effective 3D finite element (FE) based method for simulating the micro milling process under large deformations. A tooling model incorporating a helix angle is developed for cutting forces, tooling temperature and chip formation prediction. The proposed approach is experimentally validated and the simulated micro milling performance such as micro chip formation and cutting forces are in reasonable agreement with the measured results in cutting trials.

Gezielte Begrenzung der Spandickenschwankungen/Development of a counter element for influencing chip formation when machining titanium. Restriction of chip thickness deviations

2020 ◽  
Vol 110 (11-12) ◽  
pp. 806-810
Author(s):  
Sebastian Berger ◽  
Jannis Saelzer ◽  
Dirk Biermann
Keyword(s):  
Titanium Alloy ◽  
Surface Quality ◽  
Tool Life ◽  
Chip Formation ◽  
Chip Thickness ◽  
Vibration Damping ◽  
Suitable Choice ◽  
Periodic Excitation ◽  
Segmented Chip ◽  
Titanium Alloy Ti6al4v

Dieser Beitrag stellt die simulative Analyse zum Einfluss eines begrenzenden Elements zur Unterdrückung der Segmentspanbildung bei der Zerspanung der Titanlegierung Ti6Al4V vor. Dabei lässt sich aufzeigen, dass eine spanbildungsinduzierte periodische Anregung des Systems durch die geeignete Wahl von Geometrie und Positionierung des Elementes verhindert werden kann, wodurch sich die Werkzeugstandzeit und die Oberflächenqualität verbessern und schwingungsdämpfende Maßnahmen obsolet werden. This paper presents the simulative analysis of the influence of a counter element for the suppression of segmented chip formation during the machining of titanium alloy Ti6Al4V. It is shown that a chip formation induced periodic excitation of the system can be prevented by a suitable choice of geometry and positioning of the element, leading to increased tool life and surface quality as well as making vibration damping methods obsolete.

The prediction of cutting force in end milling titanium alloy (Ti6Al4V) with polycrystalline diamond tools

2016 ◽  
Vol 231 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Wencheng Pan ◽  
Songlin Ding ◽  
John Mo
Keyword(s):  
Titanium Alloy ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Polycrystalline Diamond ◽  
Force Model ◽  
Machining Parameters ◽  
Diamond Tools ◽  
Cutting Coefficients ◽  
Titanium Alloy Ti6al4v

Cutting force coefficients were conventionally described as the power function of instantaneous uncut chip thickness. However, it was found that the changes in the three controllable machining parameters (cutting speed, feed and axial cutting depth) could significantly affect the values of cutting coefficients. An improved cutting force model was developed in this article based on the experimental investigation of end milling titanium alloy (Ti6Al4V) with polycrystalline diamond tools. The relationships between machining parameters and cutting force are established based on the introduction of the new cutting coefficients. By integrating the effects of varying cutting parameters in the prediction model, cutting forces and the fluctuation of cutting force in each milling cycle were calculated. Validation experiments show that the predicted peak values of cutting forces highly match the experimental results; the accuracy of the model is up to 90% in predicting instantaneous cutting forces.

A smooth particle hydrodynamic model for two-dimensional numerical simulation of Ti–6Al–4V serrated chip deformation based on TANH constitutive law

2018 ◽  
Vol 233 (9) ◽  
pp. 3004-3017 ◽  
Author(s):  
Weilong Niu ◽  
Rong Mo ◽  
Huibin Sun ◽  
Balachander Gnanasekaran ◽  
Yihui Zhu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Chip Formation ◽  
Cutting Forces ◽  
Damage Model ◽  
Smooth Particle Hydrodynamic ◽  
Chip Morphology ◽  
Constitutive Law ◽  
Cutting Process ◽  
Serrated Chip ◽  
Cutting Model

The saw-tooth chip formation is one of the main machining characteristics in cutting of titanium alloys. The numerical simulation of saw-tooth chip formation, however, is still not accurate, since most of these numerical simulation models are based on traditional finite element method, which have difficulties in handling extremely large deformation that always occurs in the cutting process. Furthermore, these models adopt the Johnson–Cook damage constitutive law that is implemented in commercial codes such as ABAQUS® and LS-DYNA® to describe the dynamic mechanical properties of material, but Johnson–Cook damage constitutive law cannot account for the material of behavior due to strain softening and the dynamic recrystallization mechanism that occurs in the cutting process of Ti–6Al–4. Therefore, this work introduces a material constitutive model named hyperbolic tangent (TANH) and an improved smooth particle hydrodynamics method, and then develops an improved cutting model for Ti–6Al–4V titanium alloy through our in-house code to predict saw-tooth chip morphology and cutting forces. When compared to the experiments and Johnson–Cook damage model, the improved cutting model better explains and predicts the shear localized saw-tooth chip deformation as well as cutting forces.

scholarly journals Effect of tool wear on quality in drilling of titanium alloy Ti6Al4V, Part II: Microstructure and Microhardness

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Kallol Das ◽  
Mahdi Eynian ◽  
Anders Wretland
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
Surface Quality ◽  
Cutting Forces ◽  
Coolant Flow ◽  
Entry And Exit ◽  
Dry Cutting ◽  
Quality Issues ◽  
Titanium Alloy Ti6al4v

AbstractDrilling of Ti6Al4V with worn tools can introduce superficial and easily measured features such as increase of cutting forces, entry and exit burrs and surface quality issues and defects. Such issues were presented in the part I of this paper. In part II, subsurface quality alterations, such as changes of the microstructure and microhardness variation is considered by preparing metallographic sections and measurement, mapping of the depth of grain deformation, and microhardness in these sections. Drastic changes in the microstructure and microhardness were found in sections drilled with drills with large wear lands, particularly in the dry cutting tests. These measurements emphasize the importance of detection of tool wear and ensuring coolant flow in drilling of holes in titanium components.

A General Formulation of the Milling Process Equation: Contribution to Machine Tool Chatter Research—5

1968 ◽  
Vol 90 (2) ◽  
pp. 317-324 ◽  
Author(s):  
R. Sridhar ◽  
R. E. Hohn ◽  
G. W. Long
Keyword(s):  
Machine Tool ◽  
Cutting Forces ◽  
Single Point ◽  
Milling Process ◽  
Cutting Process ◽  
Varying Coefficients ◽  
Machine Tool Structure ◽  
Time Varying Coefficients ◽  
Linear Differential ◽  
Vector Matrix

In the cutting process, forces are induced at each of the cutter teeth in contact with the workpiece, and these forces in turn excite the machine tool structure. Due to the inherent feedback which exists between the cutting forces and the structure deflection, there are conditions under which this system becomes unstable. When this occurs, a condition of self-excited chatter exists. In the theory of self-excited chatter for single point tools wherein the tool is continuously in contact with the workpiece, the system can be described by a time-invariant equation, and has been rather fully developed. However, the milling process cannot be described in this manner. It is characterized by a multitooth cutter, and the cutting process itself is interrupted. Also, the direction of the cutting forces generated by each tooth does not remain constant with respect to the machine tool structure as for turning operations, but changes direction as a function of cutter position. In this paper, more complete description of the milling process is formulated. The resulting equation is a general nth order vector-matrix linear equation with periodic coefficients and a transport lag. Or equally, it is a linear differential-difference equation with time-varying coefficients. This equation is then expressed as n-first order equations (state variable form), consistent with current literature and in a form compatible for digital computer analysis.

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