Concept: the idea here is to peform casting - without the bulk melt. The molten metal comes from a MIG welder - which is a ready source of molten metal in the absence of a melting or induction furnace. The MIG wire melt is simply used as the source of molten metal.
- Steel parts almost directly from 3D prints
- Based on 3D Printing Investment Casting
- 3D print a form
- Make a cast form with Plaster of Paris or a higher temperature formula for steel.
- MIG weld into it using aluminum or steel wire.
- For aluminum, ZA, brass - plaster of paris will work
- For steel, higher temperature investment casting slurry needs to be used. This appears to be more advanced, and slurries may not be available transparently. (Refractory Cement? I have seen this being used for small scale forges, it can be found at hardware stores.
- Get flux core aluminum MIG wire (gasless) - $11 - 
- Make a 3D print with hole for electrode
- Make a mold via plaster of paris. See Plaster Mold Casting
- Fill with MIG welder
Comparison to Powder (Sintering or Melting Methods)
- Simpler lacking lasers or electron beams
- More sealed ie not porous