Green Cutting using Supersonic Air Jets as Coolant and Lubricant during Turning Authors Andrea Bareggi (presenter) Andrew Torrance Garret O’Donnell ICMR 2006 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 ICMR 2006

Introduction Difficult-to-cut materials Heat resistant alloys Hard materials Super stainless alloys (or super-alloys) Trinity College Dublin ICMR 2006 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

Coolants Trinity College Dublin ICMR 2006 Thermal damage After P. Dahlman, M. Escursell / International Journal of Machine Tools & Manufacture vol.44 (2004) pp.109–115

Coolants Trinity College Dublin ICMR 2006 Thermal damage Wearing by friction After P. Dahlman, M. Escursell / International Journal of Machine Tools & Manufacture vol.44 (2004) pp.109–115

Coolants Trinity College Dublin ICMR 2006 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

Coolants Trinity College Dublin ICMR 2006 Thermal damage Wearing by friction Built up edges Sweeping and cleaning the chip-tool interface

Improving cooling techniques Trinity College Dublin ICMR 2006 Reducing cutting forces Reducing tool wearing Reducing workpiece temperature Reducing costs Reducing environmental impact

Using air jets: why? Trinity College Dublin ICMR 2006 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 apparatus Trinity College Dublin ICMR 2006 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 setup Trinity College Dublin ICMR 2006 Cutting speed: 270 m/min Depth of cut: 0.5 mm Feed: 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 Results Trinity College Dublin ICMR 2006 Force Small reduction of forces, when using air jets

Experimental Results Trinity College Dublin ICMR 2006 Force Finishing Without jet R a = 0.83μm With jet R a = 0.75 μm

Experimental Results Trinity College Dublin ICMR 2006 Force Finishing Chip shape and colour Air jet on Air jet off

Experimental Results Trinity College Dublin ICMR 2006 Force Finishing Chip shape and colour Thermo- Camera Air jet onAir jet off

Finite Element Model Trinity College Dublin ICMR 2006 Deform-3D™ Arbitrary Lagragian Eulerian formulation adaptive non-linear remeshing algorithm fully coupled thermo-mechanical analysis

Finite Element Model Trinity College Dublin ICMR 2006 Finite Element Model Trinity College Dublin ICMR 2006 Deform-3D™ Arbitrary Lagragian Eulerian formulation adaptive non-linear remeshing algorithm fully coupled thermo-mechanical analysis Force prediction

Finite Element Model Trinity College Dublin ICMR 2006 Femlab3.1™ Frictional power Estimated specific cutting energy Heat transfer by formed chip Thermal power generation in the chip- tool interface area

Conclusions & Further Research Trinity College Dublin ICMR 2006 Heat transfer by impinging jet 1.Fluid-dynamic data 2.Estimated Nusselt number 3.Temperature measurement with hot-spot radiometer

Conclusions & Further Research Trinity College Dublin ICMR 2006 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 Research Trinity College Dublin ICMR 2006 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 Research Trinity College Dublin ICMR 2006 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 Research Trinity College Dublin ICMR 2006 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 Research Trinity College Dublin ICMR 2006 Thank you for the attention