Consolidation methods for spherical rhenium and rhenium alloys

AbstractThe development of high density spherical rhenium and spherical tungsten-rhenium powders has enabled the use of advanced consolidation techniques for the manufacture of refractory metal components. The investigated consolidation techniques are powder metal injection moulding (PIM) and vacuum plasma spraying (VPS); both produce net shape components. The required particle size distributions for these applications vary. VPS uses a large powder particle size (<44 μm) while PIM requires a fine particle size (<20 μm). The major advantages of spherical powders over traditional powders in plasma spraying are the high density of the powder particles and its good flow characteristics. These two factors combine to produce high density sprayed formed parts. PIM requires that the powder particles be dense as well as fine. Powder particles must be small enough to be entrapped in the binder but without being so small (<0·5 μm) that the body forces dominate. Binders for PIM are tailored to the powder's characteri...