Abstract: A powder injection molding process for making hard to make parts having internal cavities and hard to make parts made by the process. Metal powders having a variety of shapes and sizes are mixed with binder to make a feedstock. The feedstock is molded into at least two raw molded parts which are then sintered to join the parts together to form the hard to make part. This process eliminates all secondary operations in parts having internal cavities where core withdrawal is not possible. In preferred embodiment two raw parts are joined together during the sintering step without adding any materials to assist the bonding. This methodology can be used to make assemblies that have complex internal cavities such as filter sections and wave-guide components that are a low cost critical solution for the communications industry.

Abstract: Apparatus and method for water atomizing molten metal to provide a low oxygen metal powder. A molten metal stream is introduced to an atomization vessel containing a pressurized inert gas. The metal stream is atomized, by impingement of high pressure water within the atomization vessel. The atomization vessel has an exit aperture located so that the slurry of water and metal powder can exit from the atomization vessel only after deflection within the atomization vessel. Inert gas contained within the atomization vessel and entrapped within the slurry during atomization begins to leave the slurry during deflection, the inert gas returning to the atomization vessel atmosphere. The inert gas removal process continues after passage through the exit aperture and entrance into a closed degassing vessel.

Abstract: A process is disclosed for producing a high density spray cast metal body from a highly energetic atomized metal stream by directing said atomized stream into the interior of a mold and causing said stream to scan and fill said mold interior by effecting relative movement between said atomized metal stream and said mold, thereby producing a fine grained spray cast metal body of high density.

Abstract: Thermally induced porosity, which can lead to cracking in metal powders after consolidation, is believed to be caused by the entrapment of the inert gas used for atomization within the metal powders. The addition of an activating agent to the molten alloy prior to atomization with an inert gas, such as argon, serves to substantially reduce the porosity of metal powders. Suitable activating agents are characterized by an ability to rapidly diffuse to the surface of a molten metal particle and an affinity for oxygen. Activating agents that are useful for high nickel alloys and highly alloyed steels include magnesium, calcium, lithium, silicon, and rare earths.