Metal 3D printing uses powder materials. Anyone who knows anything about metal 3D printing knows that, but a partnership between 3D MakerJet and ZBOT has developed a prototype for a powderless wire-feed 3D printer that will use metal filament. Very few details have been released about the printer so far, but it's expected to be on the market sometime this year, so more information should be forthcoming very soon. Check out more at3DPrint.com: http://3dprint.com/117311/wire-feed-powderless-printer/