Academic insight
head to head
I’ve spent 30 years optimizing materials for use in
aerospace and automotive applications, looking
at how we design, make and use them. My latest
research focuses on the additive manufacturing
(AM) of alloys for use in aerospace applications.
We’ve received a £2.6 million (US$3.2 million) grant
for the next ten years which will enable us to
develop AM alloys for industrial applications. We’re
using one of the world’s most advanced tools to
help investigate the challenges associated with AM
alloys – Diamond Light Source the UK’s National
synchrotron science facility at Harwell near Oxford.
The synchrotron lets us see inside the alloys as the
AM machine makes components.
The synchrotron emits electrons at the speed of
light and bends them using electromagnetics to
create a continuous beam of light at wavelengths
from near infrared to hard x-rays. At the point where
the beam of electrons bends it gives us a flux of
light up to 10 million times brighter than the sun.
During the AM process we don’t know exactly
what is going on at a microstructural level in the
alloy as it solidifies. This is important as an alloy’s
strength is dependent on the microstructures
inside it. So, the research team is using the hard
x-rays from the synchrotron to get a series of 3D
images about how an alloy takes shape as a 3D
printed component builds up. Up until now we’ve
Professor Peter Lee, from University College
London is using the ultimate NDT tool,
Diamond Light Source in Oxfordshire, UK, to
improve additive manufacturing processes
only been able to look at the microstructure of a
material after it has been produced. The
synchrotron enables us to learn how to tune a
material inside itself, as we are building it.
We use cameras that capture 10,000 frames a
second – each frame is 1MB, so we accumulate
10TB a day, a massive amount of data. We are
developing characterization algorithms to detect
microstructural features, such as grain size,
A peek into
3d printing
“Using the synchrotron we can
see inside the shape to assess the
individual stresses as it is being made”
porosity or cracks. We are coding this into artificial
intelligence to automate AM processes and
creating models so components can be analyzed
prior to undergoing the AM process. One of our
main aims is to produce a closed feedback loop
control algorithm. This means when a defect like a
pore happens during manufacturing, the AM
machine can automatically take action to rebuild. If
it can’t be rebuilt we calculate the reduction in
strength and scrap it if required.
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In our test-AM machine there is also an infrared
camera and optical cameras that we calibrate by
correlating the synchrotron’s imaging to the
instruments. These highly-calibrated instruments
may one day be integrated into other AM machines.
We are also researching how to predict the lifetime
of an AM-made component to potentially enable
component-specific FAA approvals.
The results of our work is already enabling
companies to optimize their processes, such as
devising guidelines for recycling the powder. Our
research can help calibrate the metrology and NDT
aerospace engineers are doing everyday. It is
helping to develop in-situ repair technology for
components like blisks in engines and enabling AM
to produce shapes that were previously impossible
to make. Using the synchrotron we can see inside
the shape to assess the individual stresses as it is
being made inside the product. \\
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