Not so much 3D printing as 3D spraying

spray 

Engineers to fine-tune ‘cold spray,’ the next-gen 3-D printing and manufacturing technology
[Via EurekAlert! – Space and Planetary Science]

(Trinity College Dublin) Engineers from Trinity College Dublin are leading a four-year, 500,000 European Space Agency project to fine-tune ‘Cold Spray,’ — a revolutionary, environmentally friendly technology that deposits materials onto engineering components. The fruits of their labors will be seen on spacecraft in outer space as well as on a variety of household applications and on the transport vehicles we use every day.

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Looks like cool technology. No heat is needed.