There’s a gallery of images available that demonstrate the process of lost-PLA casting to create a metal object using 3D printing.
Let’s first explain the “lost-PLA” process. The idea is to do the following:
- Print an object
- Surround the object with a liquid casting material and let it harden
- Put the solid cast into a furnace to burn away all traces of the PLA, leaving a hollow mold
- Pour in some hot liquid metal and let cool into a solid
- Break away the casting material to reveal a metal cast object
- Finish as required
It sounds like a recipe, and it is. The key is that at a sufficiently high temperature, the PLA essentially evaporates into almost nothing. This enables the formation of a hollow that becomes the mold.
The anonymous set of images shows the design, 3D printing (in this case on an Ultimaker 2), casting and finishing steps.
The results are pretty decent and you can do it too, if you happen to have a vacuum, electric furnace, 3D printer and some design skills.