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Green Cutting using Supersonic Air Jets as Coolant and
Lubricant during Turning
Authors Andrea Bareggi (presenter) Andrew TorranceGarret O’Donnell
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Department of Mechanical and Manufacturing Engineering
The University of Dublin
Trinity College
Trinity College Dublin
Introduction
Difficult-to-cut materials• Heat resistant alloys• Hard materials• Super stainless alloys (or
super-alloys)
Trinity College Dublin
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Introduction
Difficult-to-cut materials• Heat resistant alloys• Hard materials• Super stainless alloys (or
super-alloys)
Trinity College Dublin
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• Nickel base alloys• Cobalt base alloys• Titanium alloys• Iron base (high chromium
stainless steel) after Seco Technical Guide, Turning Difficult-To-Machine Alloy, S. Miller, Advanced materials means advanced engines, Interdisciplinary Science Review, vol.21 (2) (1996) pp.117-129
CoolantsTrinity College Dublin
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• Thermal damage
After P. Dahlman, M. Escursell / International Journal of Machine Tools & Manufacture vol.44 (2004) pp.109–115
CoolantsTrinity College Dublin
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• Thermal damage• Wearing by friction
After P. Dahlman, M. Escursell / International Journal of Machine Tools & Manufacture vol.44 (2004) pp.109–115
CoolantsTrinity College Dublin
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• Thermal damage• Wearing by friction• Built up edges
After P. Dahlman, M. Escursell / International Journal of Machine Tools & Manufacture vol.44 (2004) pp.109–115
CoolantsTrinity College Dublin
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• Thermal damage• Wearing by friction• Built up edges
• Sweeping and cleaning the chip-tool interface
Improving cooling techniquesTrinity College Dublin
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• Reducing cutting forces
• Reducing tool wearing
• Reducing workpiece temperature
• Reducing costs
• Reducing environmental impact
Using air jets: why?Trinity College Dublin
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• Good for environment
• Not toxic for the operator
• Cheap
• Good for chip sweeping
• More likely to penetrate into the chip-tool interface
• Capable of accelerating fluid particles to give better heat transfer
Experimental apparatusTrinity College Dublin
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• Ursus 225 Centre Lathe
• Kistler piezoelectric tool-force dynamometer
• WC inserts with different nose radius
• Supersonic nozzle Silvent 1011
• Hommel roughness tester
• Infrared camera
Test setupTrinity College Dublin
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• Cutting speed: 270 m/min• Depth of cut: 0.5 mm• Feed: 0.095 mm/rev• Insert nose radius: 0.4 mm• Rake angle: 5°• Air jet pressure (nozzle
inlet): 6 bar• Insert material: WC• Workpiece material:
AISI1020 steel
Experimental ResultsTrinity College Dublin
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• Force
Small reduction of forces, when using air jets
Experimental ResultsTrinity College Dublin
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• Force
• Finishing
Without jet Ra = 0.83μm
With jet Ra = 0.75 μm
Experimental ResultsTrinity College Dublin
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• Force
• Finishing• Chip shape
and colour
Air jet on
Air jet off
Experimental ResultsTrinity College Dublin
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• Force
• Finishing• Chip shape
and colour• Thermo-
CameraAir jet on Air jet off
Finite Element ModelTrinity College Dublin
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• Deform-3D™• Arbitrary Lagragian
Eulerian formulation• adaptive non-linear
remeshing algorithm• fully coupled
thermo-mechanical analysis
Finite Element ModelTrinity College Dublin
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Finite Element ModelTrinity College Dublin
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• Deform-3D™• Arbitrary Lagragian
Eulerian formulation• adaptive non-linear
remeshing algorithm• fully coupled
thermo-mechanical analysis
• Force prediction
Finite Element ModelTrinity College Dublin
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• Femlab3.1™• Frictional power• Estimated specific
cutting energy• Heat transfer by
formed chip• Thermal power
generation in the chip-tool interface area
Conclusions & Further ResearchTrinity College Dublin
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• Heat transfer by impinging jet
1. Fluid-dynamic data
2. Estimated Nusselt number
3. Temperature measurement with hot-spot radiometer
Conclusions & Further ResearchTrinity College Dublin
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• Heat transfer by impinging jet
• Chip shape and shear plane investigation
1. Beneficial effect of the force applied on the chip by the air jet
2. Quick-stop tests
Conclusions & Further ResearchTrinity College Dublin
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• Heat transfer by impinging jet
• Chip shape and shear plane investigation
• Improve the FE modeling
1. Modeling the air jet effect (Deform)
2. Improving the friction model (Deform)
3. Improve heat transfer model in chip-tool interface (Femlab)
4. Develop a fluid-structure interaction model (Femlab)
Conclusions & Further ResearchTrinity College Dublin
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• Heat transfer by impinging jet
• Chip shape and shear plane investigation
• Improve the FE modeling
• Testing
1. Cutting parameters
2. Workpiece and insert standard materials
3. Air jet positioning
4. Investigating the use of atomized fluids
5. Investigating the use of two nozzles: overhead and flank configuration
Conclusions & Further ResearchTrinity College Dublin
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• Heat transfer by impinging jet
• Chip shape and shear plane investigation
• Improve the FE modeling
• Testing• Advanced testing
1. Nickel base alloys cutting
2. Other machining applications
Conclusions & Further ResearchTrinity College Dublin
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Thank you for the attention