ET'16 - How to Benefit from Isothermal Extrusion - Alexander Klaus ELEVENTH INTERNATIONAL ALUMINUM EXTRUSION TECHNOLOGY SEMINAR AND EXPOSITION

1. ELEVENTH INTERNATIONAL ALUMINUM EXTRUSION TECHNOLOGY
SEMINAR AND EXPOSITION
How to Benefit from
Isothermal Extrusion
Alexander Klaus

2. Constellium: a leader in innovative aluminium solutions
for the automotive, aerospace & packaging industries
2
Over 10,000 full-time employees
€5.2 billion in sales
22 manufacturing sites
C-TEC, our world-class Technology Center
Headquartered in Amsterdam, The Netherlands.
Corporate offices in Paris, France, Zurich, Switzerland and
New York, USA
2015 key figures

3. A global network of 22 facilities
3
An introduction to Constellium 2016

4. Problem: surface defects

5. Challenges
Reliability Stable process conditions,
controlled process
Productivity Ram speed, quality
Documentation Production data
Using temperature process control
 Achieve constant profile exit temperature
 Adapt ram speed and billet temperature /
taper to improve productivity
 Collect detailed process data

6. Isothermal extrusion: billet taper
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40 Exit temp. (°C)
Ram speed (mm/s)
± 1,5°C
Set billet
temperature
480°C Taper
70°C/m
Exit temp.
variation
within measuring
accuracyConstant
ram speed
Ideal state
 Constant speed
 Constant exit temp.
Achieved by correct
billet taper

7. Die limit diagram + process control problem
Billet temperature
Ram
speed
Set exit temp
1
2
±20°C
±10%
surface
defects
max.
pressure
mech.
prop.
Process control
does not detect
 Dimensional defects
 Mech. properties
 Surface defects
(only exit
temperature)
Process control
increases speed
 Is that feasible?

8. Isothermal extrusion: application

9. Speed related quality problems
 Surface defects
 Linked to exit temperature
 Not linked to exit temperature
 Dimensional defects
 Speed-sensitive dies
 Quench distortion
 Mechanical defects
 High quench exit temperature
 Metallurgical defects
 Peripheral coarse grain

10. Quality gates during extrusion
Press Quench
Cold saw
Cooling table
Log furnace
Stacker
Quality
Lab
Q1
Q2
Q3

11. Quality gates during extrusion and
recipe management strategy
Quality gates
1. QGate – at the press
 Outer surface
 Simple dimensions
 Quench settings
2. QGate – at the cold saw
 Inner surface
 Full geometry
3. QGate – at the quality lab
 Mechanical properties
 Metallurgical properties
Recipe management strategy
1. “Free Run”
 Use TPC to increase speed
2. “Delayed Run”
 Use TPC to current recipe
 1 billet trial within order (higher speed)
 Check at Q2
 Use TPC to increase recipe
/ repeat / feed back
3. “Last Billet Run”
 Use TPC to current recipe
 1 billet trial at end of order
 Check at Q3 / update recipe / repeat
product quality
can be fully
assessed

12. Conclusion
 Reliable and highly productive environment required
 Temperature process control does not prevent quality problems –
it even causes new ones
 Used correctly, process control enables increased repeatability
 Recipe management depending on quality gates
 Free run
 Delayed run
 Last billet run