Advance High Strength Low Weight Aluminum NanoFoam Alloys

This Phase I SBIR program will demonstrate SiC nano-balloon-reinforced aluminum alloy composites which have strength-density ratios 20-50% greater than Al-Li alloys. The core innovation is the production of high strength SiC nanoballoons using electrospinning of Si modified polymer nanoballoons and pyrolysis, and then using these lightweight, high strength spheres as reinforcements in aluminum alloys to both reduce weight and thermal conductivity, while simultaneously increasing strength and stiffness. A second key innovation is to add up to 5% lithium solid solution to reduce the density of aluminum, which, when combined with the 0.3-0.5g/cc Sic microballoons, will create an alloy with a density less then 1.5g/cc and strengths approaching 100ksi. The production of lightweight nanosphere analogs to carbon nanotubes represents a breakthrough to the production of low density, low thermal conductivity metal products which can be economically fabricated using powder extrusion or powder forging techniques. A nano-SiC balloon will have lower density than Li with 3X the stiffness and strength, and can be added at loadings of 20-40V%. Lithium can be added at levels up to 5 wt% (15V%), meaning that through the combined addition of lithium and SiC microballoons, 50V% of the alloy can be replaced with low density (<0.5g/cc) materials.