3D printed part
In industry today, parts are being printed in all types of materials, including metals. Only problem is the typical school, or home hobbyist, can't afford a printer like that. There you'll only see the kind that print the somewhat porous, fairly brittle "plastic". Never mind the CAD/CAM you have to learn to make the parts.
G.E. is actually printing some jet engine parts out of metal, on a production basis. Parts that cannot be machined, or that would have to be made out of several pieces welded together, are great candidates for 3D printing. You'll be seeing a lot more of this in the near future.
Check out the industrial 3D printers:
http://www.stratasys.com/
Nylon HVAC parts:
![](http://www.stratasys.com/~/media/en/Resources/Case%20Studies/Commercial%20Products/RedDOT/FDM%20Nylon%2012/RedDot-nylon-prototypes-forweb.jpg)
Polycarbonate helicopter parts:
And the most exciting of all,
Direct Metal Laser Sintering: [ame="https://www.youtube.com/watch?feature=player_embedded&v=PHaXX2OoOs4"]https://www.youtube.com/watch?feature=player_embedded&v=PHaXX2OoOs4[/ame]