SBIR-STTR Award

We propose to develop low cost diamond composite bearings utilizing our new high pressure technology for carbon fiber reinforced 3-D C/C composites and mixtures of pitch, fullerenes and nanotubes. Functionally graded bearings will be engineered to function without lubrication and to operate in Lunar dust. Tests have shown that these new materials are thermally and chemically stable, have a very high wear resistance on the diamond coated surface and can work in sand and regolith like unlubricated sliding fits. Such bearings are also extremely lightweight. Our variety of diamond coated composite would be easily scalable and cost effective to fabricate. In Phase I, we will focus on designing and prototyping precision unlubricated bearings. For Phase II and III, we will work in collaboration with leading companies that produce ceramic bearings.

In Phase I, we made prototype sliding bearings from functionally-graded, diamond-coated carbon-fiber reinforced composite. In dry-sliding experiments, the friction of the diamond-coated composites against lunar dust simulant was low and the wear was so small that it could not be detected. In contrast, all other tested materials experienced rapid abrasive wear. These tests demonstrate that diamond-coated composites are ideal materials for non-lubricated bearings, designed to operate in a lunar dust environment. The primary thrust of Phase II will be a fabrication of sliding, journal and ball bearings and testing them in low temperature vacuum chamber that corresponds to the parameters of the Moon's surface. To implement technology transfer, DMI will partner with established bearing companies. Hence, NASA will have qualified suppliers of different types of precision diamond-coated composite bearings.