<span>Background of the invention: The present invention pertains to the art of metallurgy and materials science, and more particularly to a process for producing powder metallurgy or ceramic or glass objects of simple or complex geometries. The invention is particularly applicable to a process for joining powder metallurgy objects in the green or brown state to form larger or more complex parts. The invention may be advantageously employed in other environments and applications. Although quite complex metallic shapes can be fabricated via a number of primary processes such as casting, forging, machining, and various powder-processing methods such as powder injection molding (PIM), all of these processes suffer some limitations in permissible part geometry. The limitations of the various forming methods, be they economic or technological, often dictate that a secondary joining operation is preferable or required. A number of different techniques are currently known and used to join dense monolithic parts. These include: welding, brazing, soldering, reaction bonding, adhesive joining, and use of mechanical fasteners. However, such methods generally create non-uniform structures. For example, in the case of a weld, even though its composition may be nominally the same as the base metal, the joint material and/or "heat affected zone" of the base metal has a microstructure and concomitant properties that differ from the base metal, often substantially. In the case of soldering, </span><span>brazing, and adhesive joining, a foreign material is left in the joint. Mechanical fasteners require holes that can serve as stress concentrators, and often the design must be constrained to allow access during assembly. These techniques, developed for dense monolithic materials, are also used currently for powder processed components after they are densified. The three most prevalent methods for shaping parts are casting, deformation processing, and machining. In casting, the material is melted and poured into a mold. The liquid takes the shape of the mold cavity under some combination of gravity and pressure, and subsequent solidification results in the permanent storage of the shape information. In deformation processing, the material is typically heated to lower the effective yield stress and a shaped tool is brought to bear against the plastic mass under external pressure sufficient that permanent deformation occurs. The part typically retains its shape when the stress is removed. The familiar process of machining involves selective removal of material from the surface of a solid object by the action of a machine tool. In all of these processes, the metal is a dense solid monolith at the end of the shaping process. Powder processing, however, is different. In powder processing, shaping is often mediated through the presence of a carrier fluid, which can be a water-based solution, mixture of organic liquids, or molten polymers.http://www.google.com/patents?vid=USPAT6033788</span>

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