Novel Material for Lunar Exploration

Oscar M. Suarez, University of Puerto Rico at Mayaguez, DMR 0351449 Partnership for Research and Education on Functional and Nanostructured Materials

While NASA expects to return to the moon in the next decade, a new set of materials will be needed to extend the lunar exploration sorties and to increase the payloads of the spaceships. The abrasive effect of lunar dust (regolith) on moving machinery has been noticed by the Apollo missions and requires being counteracted. PREM support allowed designing and developing a promising lightweight aluminum–based composite reinforced with ceramic particles (diborides). This low density composite bears a notable resistance to abrasion compared to existing aluminum alloys. The material can be further functionalized via centrifugal casting to possess higher wear resistance on the exposed surface of a given part while retaining its toughness in the interior for fail-safe design purposes.

For its characteristics this functionally-graded composite is also fitted for use in other machinery where low weight and abrasion resistance are a necessity, such as parts of aerospace structures and automobile applications. Atomic force microscope image of the part of a circular wear track produced on the lightweight composite designed to counteract regolith (lunar dust) erosion. For an aluminum-based material the wear track depth is very small (less than 3 µm) when a very hard (martensitic stainless) steel indenter is used to produce the track.

Z. H. Melgarejo, O. M. Suárez, K. Sridharan, “Microstructure and properties of functionally-graded Al-Mg-B composites fabricated by centrifugal casting,” Composites Part A: Applied Science and Manufacturing, (2007), [submitted]