The Influence of High Pressure Coolant on Process Optimization in Heat Resistant Super Alloys (HRSA)

Sean HoltAerospace Application ManagerSandvik Coromant

Agenda

Introduction and history of High Pressure Challenges in Machining

– Operational differences

HPC System requirements, benefits & considerations HRSA machining results & difference with other materials Future trends & directions

2

3

The History of High Pressure Coolant (HPC)

1984 1990 1996 2007 2012

Multi-taskMachining centerTurning center

Pre

ssur

e ba

r (p

si)

500(7250)

100(1450)

Ccoupling for UHPC

VTL

Standard coupling

4

High Pressure CoolantDefinitions

High Pressure Coolant (HPC)up to 80 bar (1160 psi)– Standard option on most machines

• Turning centers• Machining centers• Multi-task machines

– Standard Coromant Capto® coupling– Standard Sandvik Coromant tools available

Ultra High Pressure Coolant (UHPC)over 80 bar (1160 psi )– Standard option for a few machine manufacturers

• Limited to VTLs

– Coromant Capto® coupling for UHPC– Tool holders only as special

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Pressure (p)Force per unit area– Pascal = N/m2

– Bar = 0.1 MPa (14.5 psi)

Flow rate ()Volume displaced per time unit– liter/min (gallons/min)

Velocity (w)Speed fluid moves through a tube– m/sec (ft/sec)

High Pressure CoolantDefinitions

Kk

()

(w)

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High Pressure CoolantChallenges in machining

Operation differences:

Turning – continuous single point– Cutting temperature– Chip control

Milling – interrupted multiple teeth– Chip formation– Cutter positioning– Re-cutting of chips – unsecure or short tool life

Drilling – continuous multiple teeth– Varying cutting temperature

• hot periphery• tough center

– Chip control and evacuation through flute

HPC – Machining Requirements

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HPC – System requirements

Pump/machine

– Pressure

– Volume/flow rate

– Filter

Tool

– Nozzle diameter

– Number of nozzles

– Jet flow

– Jet direction

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HPC – System requirementsPrinciples

Reducing the area increases the velocity

Smaller outlet reduces the pressure and flow rate requirements to achieve a high velocity jet

Flow velocity w1

Flow velocity w1

w2

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Flow expressed in m3/s CD Nozzle efficiency

- 80% 20 to 300 bars (290-4350 psi)

- 70% 300 to 1000 bars (4350-14500 psi)

n Number of nozzles d Nozzle diameter (m) p Pressure (Pa) - 1 bar (100 000

Pa) - 1 psi (6895 Pa) Fluid density - for water and

cutting fluids the density is~ 1000 kg/m3

HPC – System requirementsFlow requirement

The larger the outlet area the greater the flow required to deliver a given pressureThe larger the outlet area the greater the flow required to deliver a given pressure

HPC – Machining HRSAs

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Coromant Capto® Normal coolant inlet

• Hydraulic wedge lifts the chip• Reduces temperature• Improves chip control

High precision jet nozzles

Pre-defined target areas on the insert face

HPC – Turning applications Precision is the power

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With CoroTurn® HP 70 bars (1160 psi)– Metal removal +50 at same speed– Cutting speed +20% with same total metal removal

HPC – Turning applications Inconel 718 (46HRC) -Total material removed (TMR)

Insert ap fn

CNMX 1204A2-SM S05F 2.5 mm 0.3 mm/rev

CNMX 43A2-SM S05F 0.1 inch 0.012 inch/rev

To

tal

mat

eri

al –

Q (

cm

3)

Surface cutting speed –

Vc (m/min), ft/min

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Normal Pressure 80 bar (1160 psi)

HPC – Turning applications Inconel 718 (46HRC) - Chip control

Insert vc

CNGG 120408 -SGF1105 65 m/min

CNGG 432-SGF 1105 213 sfm

Feed fn (mm/rev)

Cutting depth ap (mm)

0.15 0.2 0.25

2.0

1.0

0.5

0.25Feed fn (mm/rev)

Cutting depth ap (mm)

0.15 0.2 0.25

2.0

1.0

0.5

0.25

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CoroTurn® HP normal pressure

CoroTurn® HP 80 bars, 1160 psi

HPC – Turning applications Inconel 718 (46HRC) - Demonstration

Insert ap fn

CNGG 120408-SGF 1105 0.25 mm 0.15 mm/rev

CNGG 432-SGF 1105 0.01 inch 0.006 inch/rev

HPC – Machining in the Future

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UHPC – Turning applications The basic concept of the technique

UHPC tool - coolant supplied externally into the Coromant Capto® coupling

UHPC blanks - prepared with foursealing seats

80-1000 bar (1160-14500 psi)

HPC tool – internal coolant supply through Coromant Capto ® polygon

80 bar (1160 psi)

Coolant inletUHPC HPC

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UHPC - 230 bar (3300 psi) – 3 minsNormal coolant – 3 mins

UHPC - 300 bar (4350 psi)

UHPC – Turning applicationsEffect on Inconel 718

UHPC - 150 bar (2200 psi)

Summary

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HPC has seen significant improvements in the last few years

New technologies & methods have made machining in HRSAs more efficient

Benefits of using HPC in HRSA machining: Improves chip control Improves tool life Improves cutting speeds

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