TPT July 2011

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July 2011 107 ›
Cutting, Sawing & Saw BladeS
Titanium troubles solved by Prototyp tooling
TESTS with a Walter Prototyp carbide
milling cutter have shown Airbus that it can
transform its titanium machining capabilities,
doubling cutting volumes during roughing
operations on one workpiece.
Applied to the Ti6Al4V alloy, a 25mm
diameter Prototyp Ti40 solid carbide end mill
removed 160-200cm3/min of material at feed
rates of 50-60m/min. This compares with
80cm3/min at 25m/min using a 32mm HSS
tool – cutting data that has characterised
the Airbus workpiece since the mid-1990s.
Machining of Ti6Al4V is inherently
problematic, according to Walter GB.
The material, widely used for aerospace
applications, has extremely poor thermal
conductivity (Ti6Al4V is 7.56W/mK while
Ck45 steel is 51.9W/mK), a low elastic
modulus (110kN/mm2 compared to Ck45’s
210kN/mm2), and a distinct tendency to
‘gum’, with the machining heat being largely
dissipated by the tool’s cutting edge rather
than by the swarf, as is the case with steel.
However, Walter’s development of
titanium-compatible carbide substrates
has resulted, for example, in the Prototyp
Ti40 solid carbide end mill. This tough
and relatively vibration-immune carbide has
proved its worth in the Airbus project.
Further Walter trials – in this instance with
Ti5553 (Ti-5Al-5V-5Mo-3Cr), a near-beta
alloy with higher temperature resistance
than Ti6Al4V and a Brinell hardness of 430 –
have also proved successful when using the
Ti40 at reduced cutting speeds and feeds.
Walter’s on-going developments in
titanium machining also include larger
diameter tools that necessitate the use
of PVD Tiger.tec inserts – WSM35 with
high wear resistance for good machining
conditions and WSP45 with increased
toughness for difficult conditions.
Walter’s G77 insert geometry (with large
rake angle of 20deg) has been optimised
for titanium alloys and is now available for
shoulder mills and porcupine cutters (type
ADGT) and round insert cutters (RO.X).
Walter GB Limited – UK
Fax: +44 1527 839499
Email:
Website:
The Walter Prototyp T140 solid
carbide end mill doubled cutting
volumes on titanium at Airbus
Flying cutting machine with
double vertical blade
OLIMPIA 80 has designed and built a
new double blade flying cut-off for in-line
cutting of large pipes, in round, square and
rectangular shapes, at production speeds up
to 80-85m/min. The particular features of the
equipment make it mainly suitable for high
thickness tubes. Olimpia 80 offers different
models covering a complete range from 3"
to 16" tube OD.
The innovative system with vertical
parallel movement of blades allows the
reduction of the cutting cycle time and an
easier set up of the blades. The cutting
speed has an increase of 30-40% compared
to traditional cut-off, and the reduced contact
time of the blade into the cut tube, compared
to conventional cutting systems, allows a
reduction of the consumption of the blade
circumference.
The system uses special gear boxes,
without play, specifically designed and
ensuring higher blade resistance and longer
life. The double vertical blade cut off can be
used with HSS and TCT blades.
The equipment is completely
computerised, and the set up of the cutting
positions is performed automatically. In the
case of production of section tubes,
thanks to a universal tube blocking
system, vice change is not necessary.
Olimpia 80 Srl – Italy
Fax: +39 0523 864584
Email:
Website:
The new double blade
flying cut-off