Tungsten heavy alloys are two phase metal matrix composites that provide unique strength, ductility and density combinations when liquid phase sintered. They are used in military and commercial applications requireing costly, complex shaped final forms that result in expensive material losses due to machining. Powder injection molding (PIM) is a process ideally suited for producing complex net shape parts while retaining the unique property combination of the tungsten heavy alloys which are extremely sensitive to processing conditions, impurities and post sintering treatments. Phase I has successfully demonstrated that PIM of a 95W heavy alloy can produce material properties that are equivalent to or exceed press/sinter processing. In Phase II, TAC will investigate the feasibility of injection modling XM-919 kinetic energy penetrators and golf irons from new tungsten heavy alloys doped with different additivies. The heavy tungsten alloys will be engineered for the penetrator, to maximize tensile strength, and for the golf iron, to optimize the elastic modulus. Phase II will address: alloying additives, powder-binder mixing, optimum solid loading of the binder, mold flow geometries, injection molding, debinding, proper sintering/heat treatment schedules, added value geometries tensile strength and elastic modulus properties for each application.
Benefits: Military application include electronic packaging, hardened tooling, and high precesion metal components. Commercial applications include golf club putters, medical applications, automotive applications, environmental work, to name a few. Precision components will be able to be made iwth specifically desired hardness, density, weight, etc.
Keywords: tungsten heavy alloys injection molding value added additives metal matrix composites
