Description: Boron nitride nanotube (BNNT) reinforced metal matrix composites (MMCs) provide potential for advanced lightweight high stiffness structures that are critical for virtually all NASA space missions. State of the art powder metallurgy and fusion processing to produce BNNT MMC have resulted in disappointing results that in part relate to poor dispersion of the BNNTs, poor interface bonding and high porosities in the MMC. A new breakthrough method of producing nanotube MMCs consists of friction stir processing (FSP) which is a solid state/non-melt process that produces pore/defect-free MMCs with excellent metal matrix interface bond. The FSP process produces aligned nanotube MMCs with substantially enhanced mechanical properties. BNNTs shall be processed to produce alignment and coupled with the FSP additive manufacturing process (FSAM) that demonstrates enhanced properties over monolithic light metals of magnesium, aluminum and titanium. Samples shall be produced that verify enhanced properties, FSAM shall demonstrate producing example parts with an economic model generated for application to NASA structures.

Benefits: Metal matrix composites (MMCs) of boron nitride nanotubes (BNNTs) exhibiting exemplary properties of strength, stiffness and light weight can be utilized to a significant advantage in virtually all NASA missions.

The very high cost of BNNTs preclude their utilization in composites for commercial application except for some very high cost incentive applications. However, the technology to produce the nanotube MMCs provides a basis to utilize carbon nanotube MMCs and friction stir additive manufacturing (FSAM) processing can be applied throughout the large and rapid growing additive manufacturing market.