The Influence of High Pressure Coolant on
Process Optimization in Heat Resistant
Super Alloys (HRSA)
Sean Holt
Aerospace Application Manager
Sandvik 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
The History of High Pressure Coolant (HPC)
Pressure bar (psi)
500
(7250)
Ccoupling for UHPC
VTL
100
(1450)
Standard coupling
1984
3
Multi-task
Machining center
Turning center
1990
1996
2007
2012
High Pressure Coolant
Definitions
 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
4
High Pressure Coolant
Definitions
 Pressure (p)
( )
Force per unit area
– Pascal
– Bar
N/m2
=
= 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)
5
K
k
(w)
High Pressure Coolant
Challenges 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
6
HPC – Machining Requirements
HPC – System requirements
 Pump/machine
 Tool
– Pressure
– Nozzle diameter
– Volume/flow rate
– Number of nozzles
– Filter
– Jet flow
– Jet direction
8
HPC – System requirements
Principles
 Reducing the area
increases the velocity
 Smaller outlet reduces the
pressure and flow rate
requirements to achieve a
high velocity jet
9
Flow
velocity w1
Flow
velocity w1
w2
HPC – System requirements
Flow requirement
 
 CD
Flow expressed in m3/s
Nozzle efficiency
- 80% 20 to 300 bars (290-4350 psi)
- 70% 300 to 1000 bars (4350-14500 psi)
n
d
p

Number of nozzles
Nozzle diameter (m)
Pressure (Pa) - 1 bar (100 000 Pa)
- 1 psi (6895 Pa)
Fluid density - for water and
cutting fluids the density is
~ 1000 kg/m3
The larger the outlet area the greater the flow required to deliver a given pressure
10
HPC – Machining HRSAs
HPC – Turning applications
Precision is the power
• Hydraulic wedge lifts the chip
• Reduces temperature
• Improves chip control
Coromant Capto®
Normal coolant inlet
High precision jet nozzles
Pre-defined target areas on
the insert face
12
HPC – Turning applications
Inconel 718 (46HRC) -Total material removed (TMR)
ap
fn
CNMX 1204A2-SM S05F
2.5 mm
0.3 mm/rev
CNMX 43A2-SM S05F
0.1 inch
0.012 inch/rev
With CoroTurn® HP 70 bars (1160 psi)
– Metal removal +50 at same speed
– Cutting speed +20% with same total metal removal
Total material – Q (cm3)
Insert
Surface cutting speed –
Vc (m/min), ft/min
13
HPC – Turning applications
Inconel 718 (46HRC) - Chip control
Insert
vc
CNGG 120408 -SGF1105
65 m/min
CNGG 432-SGF 1105
213 sfm
Normal Pressure
80 bar (1160 psi)
Cutting depth
ap (mm)
Cutting depth
ap (mm)
2.0
2.0
1.0
1.0
0.5
0.5
Feed
fn (mm/rev)
0.25
0.15
14
0.2
0.25
Feed
fn (mm/rev)
0.25
0.15
0.2
0.25
HPC – Turning applications
Inconel 718 (46HRC) - Demonstration
Insert
ap
CNGG 120408-SGF 1105
0.25 mm
0.15 mm/rev
CNGG 432-SGF 1105
0.01 inch
0.006 inch/rev
CoroTurn® HP
normal pressure
15
fn
CoroTurn® HP
80 bars, 1160 psi
HPC – Machining in the Future
UHPC – Turning applications
The basic concept of the technique
UHPC
HPC
Coolant inlet
 UHPC tool - coolant supplied externally  HPC tool – internal coolant supply
through Coromant Capto ® polygon
into the Coromant Capto® coupling
 80 bar (1160 psi)
 UHPC blanks - prepared with four
sealing seats
 80-1000 bar (1160-14500 psi)
17
UHPC – Turning applications
Effect on Inconel 718
Normal coolant – 3 mins
UHPC - 230 bar (3300 psi) – 3 mins
UHPC - 150 bar (2200 psi)
UHPC - 300 bar (4350 psi)
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Summary
 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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