Freeform fabrication of functional aluminium prototypes using powder metallurgy

Freeform fabrication methods allow the direct formation of parts built laye r by layer, under the control of a CAD drawing. Most of these methods form parts in thermoplastic or thermoset polymers, but there would be many appli cations for freeform fabrication of fully functional metal or ceramic parts . We describe here the freeforming of sinterable aluminium alloys. In addit ion, the building approach allows different materials to be positioned with in a monolithic part for an optimal combination of properties. This is illu strated here with the formation of an aluminium gear with a metal-matrix co mposite wear surface. (C) 1999 Kluwer Academic Publishers.