Presentation given by Sir Micahel Nairn, Chairman Rautomead Limted, at Interwire 2019. Abstract Many modern industrial applications of copper-based conductor wires call not only for high electrical conductivity, but also for other matching physical properties, including high tensile strength, high softening temperatures, creep resistance, abrasion resistance and corrosion resistance, while maintaining also good ductility. The paper shows examples of dilute copper alloys offering these properties and techniques and equipment which have been developed by Rautomead for reliable, continuous production to narrow chemical tolerances.

1. Rautomead Limited

2. Rautomead Limited
“Continuous Casting of Dilute
Copper Alloys for Drawing to
Wire in Specialist Applications”

3. Rautomead Limited
Introduction to Rautomead
• Established in 1978 in Scotland, UK
• Development and exploitation of the technology of
continuous casting of non-ferrous metals
• 390 installations worldwide, including 86 for oxygen-free
copper and copper conductor alloys
• Life-long technical support for customers
• Strong focus on technical innovation

4. Rautomead Limited
Characteristics of the Technology
• Elimination of Intermediate Processes
• Near Net Size Production
• Reduction in Capital Investment
• Reduction in Cost of Production
• Semi-finished Wire Rod Closer to Point of Use

5. Rautomead Limited
Dilute Copper Alloy
Types
Group A Group B
Copper Chrome Zirconium Copper Magnesium
Copper Zirconium Copper Tin
Copper Iron Titanium
Magnesium
Silver-bearing Copper
Copper Titanium Copper Silicon Manganese

6. Rautomead Limited
Dilute Copper Alloy
Types
Group A Applications
Copper Chrome Zirconium Railway wire
Welding tips
Commutator sections
Copper Zirconium EDM wire
Magnet wire
Copper Iron Titanium
Magnesium
Automotive wire
Copper Titanium Replacement for CuBe

7. Rautomead Limited
Dilute Copper Alloy
Types
Group B Applications
Copper Magnesium Railway wire
Automotive wire
Copper Tin Railway wire
Electrical spring wire
Silver-bearing Copper Alternator windings
Terminals, switches, contacts
Copper Silicon Manganese Automotive welding wire

8. Rautomead Limited
Market Sectors
Sector Drivers
Automotive Reduced Emissions,
Electric Traction, Reduced
Weight, Greater Range,
More Gadgets, Longer
Warranty Periods, Lower
Life-time Cost
Electronics & Industrial Miniaturisation, Higher
Tensile Strength, Higher
Flexural Strength
Railways Higher Speed, Higher
Strength, Reduced Creep,
Long Uninterrupted
Lengths

9. Rautomead Limited
Target Properties
Good Electrical Conductivity & Ductility,
but also
Higher tensile strength
Higher softening temperature
Improved abrasion resistance
Better creep resistance
Better corrosion resistance
Avoidance of toxic hazards

10. Rautomead Limited
Principal Alloying Elements
Silver
Tin
Ag
Sn
<4.0
%
<0.2
%
High softening temperatures
Good corrosion resistance
Manganese
Magnesium
Mn
Mg
<1.0
%
<0.6
%
High tensile strength
High tensile strength
Chrome Cr <1.0
%
High strength. Age hardening
Silicon Si <3.0
%
High tensile strength
Zirconium Zr <1.0
%
High softening temperatures
Iron Fe <2.0 High tensile strength

11. Rautomead Limited
Technical Challenges
Solubility in Copper
Formation of Oxides and Nitrides
Thorough Mixing
Volatility of Elements
Aggressive Nature of Elements
Material Losses
Process Yield

12. Rautomead Limited
Cored Wire Feed
powder
Chromium
Zirconium
Magnesium
programme
d
additions

13. Rautomead Limited
grain
Silver
Tin
automatic
dosage
Grain
Feed

14. Rautomead Limited
RSL 1400
Cu Cr Zr
Cored Wire Feed
Sealed Lid
Group A
Cr0.6, Zr0.04,
Cu
Cr +/- 0.01%
Zr +/- 0.005%

15. Rautomead Limited
RSL 1400
Cu Cr Zr
Cored Wire Feed
Sealed Lid
Group A

16. Rautomead Limited
RSL 1400
Cu Cr Zr
Cored Wire Feed
Sealed Lid
Group A

17. Rautomead Limited
RSL 1400
Cu Zr 0.35
as-cast 15mm
Group A

18. Rautomead Limited
RSL 1400
Cu Zr 0.35
as-cast 15mm
Group A

19. Rautomead Limited
RS 3000S
Cu Mg
5 strands
8 – 30mm
dia.
Mg +/- 0.01%
Group B

20. Rautomead Limited
RS 3000S
Cu Mg
multiple
strands
8 – 30mm dia
Group B

21. Rautomead Limited
RS 1000
Cu Ag
vertical &
horizontal
8 – 30mm
dia.
Ag +/-0.002%
Group B

22. Rautomead Limited
RS 3000S
Cu Mg
5 strands
8 – 30mm dia.
Group
B

23. Rautomead Limited
RS 3000S
Cu Mg
Catenary Wires
Messenger Wire
Dropper Wire
Contact Wire
Group B

24. Rautomead Limited
Furnace Cut-Away (RS 3000S)

25. Rautomead Limited
Graphite Crucible and Heating Elements (RS 3000)

26. Rautomead Limited
Graphite Heating Elements

27. Rautomead Limited
Graphite Crucible

28. Rautomead Limited
Joint Projects between Rautomead and University of
Dundee
Modelling of the continuous casting process
Fundamental studies of temperatures, movement and
solidification
Technical
Innovation

29. Rautomead Limited
Base case in oxygen-free copper at 8mm diameter with
push-back control
Validation in comparison with practical results
Objectives to
 Predict casting behaviour
 Identify defects in cast rod
 Investigate unique casting phenomena
Simulation of Casting
Process

30. Rautomead Limited
Graphite/Ceramic, die-
cap-packing materials
Supercooler
Metal/alloy meltcm
cm
Crucible
Resistance Heaters
2-D Area
Simulated

31. Rautomead Limited
Supercoolers at 25 oC
Red = Hot
(1200 oC)
Blue = cold
(25 oC)
Heat Flow Within Die & Crucible

32. Rautomead Limited
Red =
Hot
liquid
metal
Blue =
cold
Solid
metal
Arrows show
fluid and
solid
motions
Solidification Within
Die

33. Rautomead Limited
Red = Faster
Blue = slow
Arrows
show
fluid and
solid
motions
Velocity Flow Within Die & Surrounding
Crucible

34. Rautomead Limited
Simulated Liquid Fraction

35. Rautomead Limited
8mm dia. oxygen-free as cast copper rod

36. Rautomead Limited
Phase-field coupled Monte-Carlo Potts Simulation

37. Rautomead Limited
“Technology Never Stands Still”
Thank you
www.rautomead.com
Rautomead Limited
PO Box 100, Dundee DD1 9QY
Scotland, U.K.
www.rautomead.com