(Left) Fig 3: Small flexible
enclosure used during
development exercises. The
robot/enclosure interface
is effectively sealed against
leaks using an adaptable
occlusion.
(Left) Fig 4: One of the largest 3D metal
parts in the UK has now been produced
as a result of the Cranfield research.
Designed by BAE Systems engineers,
the part measures 1.2m in length and
is made from titanium alloy. Known
as a ‘spar section’ this forms a main
structural element in the aircraft wing
and took just 37 hours to build from
a digital model, where previously this
process would have taken many weeks.
Multiple access points.
References
Systems can be manufactured with numerous
access locations for personnel gloves and gas/
electrical entries. Large leak-tight zips afford easy
access for components.
1
P.A. Kobryn, U.S. Air Force Research Laboratory,
Materials and Manufacturing Directorate, AFRL/MLLMP,
Wright-Patterson AFB, OH 45433 USA
2
P. Edwards, A. O’Conner and M. Ramulu
J. Manuf. Sci. Eng 135(6), 061016 Nov 18, 2013
3. Current activity at TWI and Warwick University
(UK), Trumpf (D), ARCAM (S) and University of Texas
(USA).
4. Design for Wire and Arc Additive Layer
Manufacture. J. Mehnen, J. Ding,
Lockett, P. Kazanas. Manufacturing Department,
Cranfield University
5. Williams, S.W., Martina, F., Addison, A.C., Ding, J.,
Pardal G., and Colegrove, P.,
2015. Wire + Arc Additive Manufacturing, , Materials
Science and Technology
6. Huntingdon Fusion Techniques Ltd, United
Kingdom. www.huntingdonfusion.com
7. Brooks R. Siemens Now Producing Gas Turbine
Parts by Metal 3D Printing. American Machinist Feb 4,
2016
The largest facility supplied to the Cranfield
Welding Engineering Research Centre has a
volume of 27 cu m, adequate to accommodate
all work-pieces, welding equipment and even
a programmable robotic system. The research
team ensure that the optimum gas environment
during welding of titanium alloys is achieved by
evacuating the enclosure prior to admitting high
purity argon gas. This gives an operating oxygen
content well below 100 ppm (0.01%) and for the
Cranfied team this is considered low enough to
prevent significant oxidation of titanium alloys
during welding and cooling.
Author: Dr Michael J Fletcher, Delta Consultants
45
TN MAY 2016