Materials behavior and manufacturing aspects of higher-performance refractory materials by combustion-driven higher pressure powder compaction

摘要

We are presenting the results of higher pressure powder compacted materials processing and properties of select refractory materials and their composites such as tungsten, molybdenum, TZM, Rhenium, Moly-Rhenium, Tungsten-Rhenium alloys compacted using 300/400 Ton Press of Combustion Driven Higher Pressure Powder Compaction (CDC) Manufacturing Technology are presented. The unique process advantages of higher pressure CDC compaction (e.g., up to 150 tsi) include: much higher part densities in green and sintered conditions, rapid pressing times (milliseconds) unlike the conventional hot-pressing/HIPing methods, ability to press powders of varying sizes, ability for layered materials bonding/fabrication (e.g., Steel/Copper, Rhenium/Moly-Rhenium) to scale-up for production using automated pressing to fabricate several parts/minute based on the complexity and levels of the part geometry, near net shaping ability, less part shrinkages due to higher as-pressed densities and improved microstructural and materials behavior. Efforts to optimize the process conditions together with effects on geometrical, physical, microstructures and select mechanical properties such as hardness, strength and ductility are discussed and technological advantages of higher pressure consolidation manufacturing for scientific advancement and several key commercial applications are presented. Potential commercial applications of CDC technology include higher performance armor ceramics, rocket motor components, bearings, gears, advanced permanent magnets, RF accelerator subsystem accessories, laser optical mirror substrates/heat sinks, x-ray targets, high temperature components, projectiles/ammunitions, advanced ceramics for transparent armors, IR/missile domes, performance valves, high temperature parts and biomedical parts. The produced parts are of near net shape or net shape quality at compaction pressures up to 150 tsi which revealed higher part densities and improved microstructural and mechanical properties than attainable by conventional lower pressure 690 MPa (<50 tsi) powder metallurgical (P/M) techniques, under optimized CDC compaction and post-process thermal conditions.