Near Net Shape Manufacturing Using Combustion Driven Compaction

73102-This project will develop a near-net-shape manufacturing technology, Combustion Driven Compaction (CDC) of alloy powders, for critical parts used in Next Linear Collider (NLC) structures. These parts include OFHC (oxygen-free high conductivity) copper disks and SiC-based microwave absorbers for Higher Order Mode Manifold Radio-Frequency (RF) Internal Load applications. These parts are very important in linear accelerators that operate under intense RF microwave power and require cost-effective manufacturing. The CDC process will be cost-effective and competitive with other traditional processes such as wrought process/casting/forging in terms of net shaping ability to fabricate simple to complex shapes, faster time of compaction, better densification, improved mechanical/conductivity, excellent sub-micron surface finish, controllable geometrical tolerances, and brazeable/machinable attributes. Phase I showed that CDC processing could be used to fabricate copper samples of various geometrical shapes at various CDC high compaction pressures for NLC copper-disk structure applications. Structure/property relationships and sintering responses were optimized for improving the density, microstructure, uniform microchemistry, and polycrystalline single phase in the crystal structure and sub-micron surface finishes. Phase II will further develop the CDC processing, sintering responses, and structure/property optimization. Materials characterization and testing will include mechanical properties, microstrutural/microchemistry/crystal structures, helium leak resistance, conductivities, RF properties of dielectric behavior, brazability, and machinability. Commercial Applications and Other Benefits as described by awardee: The CDC process should be applicable to the cost-effective manufacturing of RF microwave parts, x-ray targets (for bio-medical, homeland security, and quality control screening), sputtering targets, NLC copper disks, vacuum seals for accelerators , cryogenic components, high temperature heat shields/tiles/nozzle liners for missiles/rockets, automotive/aerospace brake parts, nuclear storage pellets, military ammunitions, bearings, valves/valve seats, piston-rings, pump covers, superconducting magnets, die inserts/molds/cutting tools, Functionally Gradient Materials, and dissimilar/difficult-to-weld material bonding.