A copper lattice
structure created with Northwestern Engineering's new 3-D printing process
(January 11, 2016) New
rapid method expands the types of metals, alloys, and architectures that can be
additively manufactured
A team of Northwestern Engineers has created a new way to
print three-dimensional metallic objects using rust and metal powders.
While current methods rely on vast metal powder beds and
expensive lasers or electron beams, Northwestern’s new technique uses liquid
inks and common furnaces, resulting in a cheaper, faster, and more uniform
process. The Northwestern team also demonstrated that the new method works for
an extensive variety of metals, metal mixtures, alloys, and metal oxides and
compounds.
“This is exciting because most advanced manufacturing
methods being used for metallic printing are limited as far as which metals and
alloys can be printed and what types of architecture can be created,” said
Ramille Shah, assistant professor of materials science and engineering in the
McCormick School of Engineering and of surgery in the Feinberg School of
Medicine, who led the study. “Our method greatly expands the architectures and
metals we’re able to print, which really opens the door for a lot of different
applications.”
Conventional methods for 3-D printing metallic structures
are both time and cost intensive. The process takes a very intense energy
source, such as a focused laser or electron beam, that moves across a bed of
metal powder, defining an object’s architecture in a single layer by fusing
powder particles together. New powder is placed on top on the previous layer,
and these steps are repeated to create a 3-D object. Any unfused powder is
subsequently removed, which prevents certain architectures, such as those that
are hollow and enclosed, from being created. This method is also significantly
limited by the types of compatible metals and alloys that can be used.