3D printing metals has advanced so much in recent years. It is possible to print parts with gradients of different metals.
Now a team of engineers from Northwestern University, USA has created a way to print three dimensional metallic objects using metal powders. Rust all prepared in the form of paints in liquid or paste form to paint with rust (outstanding). While the current methods use “beds” of powdered metal and high power lasers or electron beams new technique uses liquid paints and common ovens resulting in a faster, cheaper and more uniform results.
New method works for wide variety of metals, mixtures of metals, alloys, compounds and metal oxides, including iron oxide, or rust.
“Our method expands enormously architectures and metals that we are able to print, which really opens the door to a number of different applications” said engineer Ramille Shah, Coordinator of the team.
Sintering and extrusion
Instead of a very intense energy source such as a laser or an electron beam used to melt the powdered metal particles, used in conventional methods for 3D printing, the new method dispenses with the so-called “bed of powder” and the energy beam, in addition to split the process into two steps: printing and merging the layers.
The first step uses a liquid metal ink or a mixture of metallic powders, solvents and an elastomer Binder released through a nozzle ink at room temperature. Despite starting with a liquid ink extruded material the nozzle solidifies instantly and merges with the material already filed, allowing manufacture large objects that can be handled immediately.
2. In the second step
Already in its final form, the piece is annealed by heating in an oven process known as sintering, in which metallic powders come together without merger. “By separating and sintering, it seems that complicate the process,” says professor David Dunand. “But, in fact, he released, since each step is much easier to separately than combined approach”.
This simplification should assist in the improvement of the technique with a view to obtaining pieces that can decrease or eliminate the need for final treatment.