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3D–Printed Rocket Engines

Unintended explosions are in fact so common that rocket
scientists have come up with a euphemism for when it
happens: rapid unscheduled disassembly, or RUD for short.
Every time a rocket engine blows up, the source of the failure
needs to be found so that it can be fixed. A new and improved
engine is then designed, manufactured, shipped to the test site
and fired, and the cycle begins again – until the only
disassembly taking place is of the slow, scheduled kind.
Perfecting rocket engines in this way is one of the main
sources of developmental delays in what is a rapidly
expanding space industry.

Today, 3D printing technology, using heat-resistant metal
alloys, is revolutionising trial-and-error rocket development.
Whole structures that would have previously required hundreds
of distinct components can now be printed in a matter of days.
This means you can expect to see many more rockets blowing
into tiny pieces in the coming years, but the parts they’re
actually made of are set to become larger and fewer as the
private sector space race intensifies.

Rocket engines generate the energy
equivalent of detonating a tonne of TNT
every second, directing that energy into
an exhaust that reaches temperatures
well over 3,000 celsius. Those engines
that manage this without rapidly
dissembling in an unscheduled fashion
take at least three years to engineer from
scratch, most of which is taken up by the
cyclical process of redesign, rebuild,
refire and repeat.
Increasingly, engineers are favouring a process
called selective laser sintering to 3D-print rocket
engine parts in an additive process. It works by
first laying down a layer of metal powder, before
melting shapes into the powder with lasers. The
metal binds where it’s melted, and remains
powder where it’s not. Once the shape has
cooled, another layer of powder is added, and
the part is built up layer by layer. For rocket
engines, an Inconel copper super alloy powder is
used, because it can withstand very high
temperatures. Selective laser sintering allows for
multiple components to be printed in-house, as
one unified part, in a matter of days.
Courtesy—The Conversa on

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