Some Effect of Environment of Work Surface in Metal Cutting : 2nd Report, Shear Angle, Friction Angle and Cutting Energies

1976 ◽  
Vol 42 (353) ◽  
pp. 307-315 ◽  
Author(s):  
Katsumi SAKAKIDA ◽  
Zenjiro WATANABE ◽  
Masami MASUKO
Keyword(s):  
Metal Cutting ◽  
Friction Angle ◽  
Shear Angle ◽  
Work Surface

Research on Improvement of Merchant Shear Angle Model

2014 ◽  
Vol 894 ◽  
pp. 192-200 ◽  
Author(s):  
Shu Ting Wang ◽  
Yu Cheng Zhang ◽  
Wei Dong Gou ◽  
Chuan Jiang Liu
Keyword(s):  
Metal Cutting ◽  
Friction Angle ◽  
Calculation Model ◽  
Shear Angle ◽  
Zone Model ◽  
Analysis Model ◽  
Calculation Results ◽  
The Impact ◽  
Angle Calculation ◽  
Key Parameter

Shear angle is a key parameter to characterize the metal cutting. In this paper the Merchant analysis model of shear angle is improved. The impact of shear angle on the shear stress is quantitatively analyzed by using of the unequal division shear zone model and Johnson-Cook constitutive model, and the functional relationship between the tool-chip friction angle and the shear angle is established by Schulz empirical formula. Thus the new shear angle calculation model is established. Calculation results and experiments verify the effectiveness of the improved Merchant model.

Effect of Surface Slope on Shear Angle in Metal Cutting

1970 ◽  
Vol 92 (1) ◽  
pp. 115-118 ◽  
Author(s):  
G. Boothroyd
Keyword(s):  
Metal Cutting ◽  
Chip Thickness ◽  
Shear Angle ◽  
Rate Of Change ◽  
Cutting Condition ◽  
Surface Slope ◽  
Undeformed Chip Thickness ◽  
Work Surface ◽  
Machine Tool Chatter ◽  
Effect Of Surface

The effect of the work surface slope, or the rate of change of undeformed chip thickness, on the shear angle in metal cutting is studied experimentally. It is shown that the results of previous analyses only apply to one specific cutting condition and cannot generally be used in studies of machine tool chatter.

scholarly journals Influence of the Rake Angle on Nanocutting of Fe Single Crystals: A Molecular-Dynamics Study

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 516 ◽  
Author(s):  
Iyad Alabd Alhafez ◽  
Herbert M. Urbassek
Keyword(s):  
Molecular Dynamics ◽  
Chip Thickness ◽  
Mass Conservation ◽  
Friction Angle ◽  
Rake Angle ◽  
Shear Angle ◽  
Dynamics Simulation ◽  
Burgers Vector ◽  
Edge Dislocations ◽  
Cutting Direction

Using molecular dynamics simulation, we study the cutting of an Fe single crystal using tools with various rake angles α . We focus on the (110)[001] cut system, since here, the crystal plasticity is governed by a simple mechanism for not too strongly negative rake angles. In this case, the evolution of the chip is driven by the generation of edge dislocations with the Burgers vector b = 1 2 [ 111 ] , such that a fixed shear angle of ϕ = 54.7 ∘ is established. It is independent of the rake angle of the tool. The chip form is rectangular, and the chip thickness agrees with the theoretical result calculated for this shear angle from the law of mass conservation. We find that the force angle χ between the direction of the force and the cutting direction is independent of the rake angle; however, it does not obey the predictions of macroscopic cutting theories, nor the correlations observed in experiments of (polycrystalline) cutting of mild steel. Only for (strongly) negative rake angles, the mechanism of plasticity changes, leading to a complex chip shape or even suppressing the formation of a chip. In these cases, the force angle strongly increases while the friction angle tends to zero.

On the Effects of a Built-Up Edge on Acoustic Emission in Metal Cutting

1990 ◽  
Vol 112 (2) ◽  
pp. 184-189 ◽  
Author(s):  
D. V. Hutton ◽  
Qinghuan Yu
Keyword(s):  
Acoustic Emission ◽  
Experimental Evidence ◽  
Deformation Zone ◽  
Metal Cutting ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Rake Angle ◽  
Shear Angle ◽  
Cutting Conditions ◽  
Effective Rake Angle

Experimental evidence is presented which indicates that the presence of a built-up edge can significantly affect the generation of acoustic emission in metal cutting. Results for machining SAE 1018 and 4140 steels show that the built-up edge can mask the generally accepted AE-cutting speed relation when cutting tools having small rake angles are used. Under cutting conditions conducive to development of a built-up edge, it is shown that increased acoustic emission is generated as a result of increased effective rake angle and corresponding increase of shear angle in the primary deformation zone. Three distinct types of built-up edge have been observed and classified as immature, periodic, or developed, according to effect on acoustic emission.

Experimental Study on Effects of Feed per Tooth on Shear Angle and Friction Angle in Orthogonal Milling of Titanium Alloy

2014 ◽  
Vol 941-944 ◽  
pp. 1947-1951
Author(s):  
Wan Zhu Liu ◽  
Qiang Liu
Keyword(s):  
Titanium Alloy ◽  
Physical Phenomenon ◽  
Orthogonal Cutting ◽  
Friction Angle ◽  
Milling Process ◽  
Shear Angle ◽  
Experimental Results ◽  
Force Modeling ◽  
Increase With Increase ◽  
Cutting Model

Shear angle and friction angle are the two characteristic parameters in orthogonal cutting model. This paper investigated effects of feed per tooth on shear angle and friction angle in orthogonal milling of titanium alloy Ti6Al4V by experimental approach. Three different straight tooth milling tool with different rake angles are used in this research. Experimental results reveals that in orthogonal milling of Ti6Al4V alloy, shear angle will decrease with increase of feed per tooth and friction angle will increase with increase of feed per tooth. And then variation of shear angle and friction angle affect the values of force coefficients. The experimental results provide deep understand of basic physical phenomenon in milling process and sheds light on more accurate cutting force modeling.

Theoretical and numerical modeling of tool–chip friction in ultrasonic-assisted turning

2018 ◽  
Vol 233 (4) ◽  
pp. 824-838 ◽  
Author(s):  
Mohammad Lotfi ◽  
Saeid Amini ◽  
Hossein Ashrafi
Keyword(s):  
Thermal Conduction ◽  
Metal Cutting ◽  
Contact Length ◽  
Friction Model ◽  
Shear Angle ◽  
Sliding Contact ◽  
Simulation Methods ◽  
Ultrasonic Assisted ◽  
Cutting Operation ◽  
Intermittent Contact

Decrease of friction in tool–chip contact zone is a key subject in metal cutting operation. Therefore, effect of ultrasonic vibration in this area is analyzed by using experimental and simulation methods. In this study, a theoretical model is firstly developed based on the shear friction model, and then sticking–sliding contact zones plus their contact lengths are defined in order to simulate conventional and ultrasonic-assisted turning. Accordingly, shear angle, sticky length, and cutting forces were measured in experiments as input parameters for the calculation of friction coefficients. As a result, intermittent contact of vibrated tool decreases the time of thermal conduction in tool–chip interface, resulting in a significant reduction in friction coefficient and contact length, particularly, in sticky region.

Dynamics of the Metal-Cutting Process

1965 ◽  
Vol 87 (4) ◽  
pp. 429-441 ◽  
Author(s):  
Paul Albrecht
Keyword(s):  
Dynamic Response ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Dynamic Properties ◽  
Chip Thickness ◽  
Cutting Process ◽  
Uncut Chip Thickness ◽  
Work Surface ◽  
Experimental Approaches ◽  
Inertia Forces

An investigation into the dynamics of the metal-cutting process has been carried out using analytical and experimental approaches. An exploratory analysis into the dynamic behavior of the cutting process revealed such dynamic properties as a loop response of the cutting forces caused by the waviness of the work surface. This finding indicates the possibility of unstable behavior of the cutting process in itself. It was possible to describe analytically the phase between the force response and fluctuations of uncut chip thickness for the case of a wavy work surface. Effects of the magnitude of the shear angle as well as of its fluctuations have been studied which make it possible to correlate the instability within the cutting process to the properties of the work material. Apart from the configuration of the cutting process, its physical properties, such as inertia forces in chip formation, have been introduced into the analysis because inertia forces, negligible at steady state, may grow significant if cutting conditions are fluctuating at higher frequencies. An experimental setup has been devised and built featuring a special design of a tool dynamometer particularly suitable for the measurement of dynamic response of the cutting forces. In the setup, a cutting tool activated by a hydraulic shaker is controlled in an average position by a feedback loop mechanism. This setup makes it possible to obtain a record of the dynamic response of cutting forces caused by the fluctuation of uncut chip thickness produced by an oscillating tool in the frequency range up to about 400 cps.

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