Project Title:

Thin-Walled Metal Matrix Composites for Spacecraft Applications

04.06-3200B
Project Title:Thin-Walled Metal Matrix Composites for Spacecraft Applications
Company:Foster-Miller Inc.
Waltham, MA 02254
Principal Investigator:RichardW. Lusignea

Abstract:

Graphite-magnesium and graphite-aluminum MMC's are ideal materials for spacecraft
applicaitons owing to their high strength and stiffness, light weight, no out-gassing,
good thermal and electrical conductivity, and resistance to the space environment.
 Continuously reinforced, thin-walled metal matrix parts will be particularly useful
in spacecraft as stiff, dimensionally stable structural members.  Thinner parts will
permit more efficient designs, resulting in reduced weight, increased payload, and
higher structural resonances.  Continuous reinforcement will allow design of zero
CTE structures for increased dimensional stability over wider temperature ranges
and more accurate pointing angles for reflectors and antennae.  To take full advantage
of MMC's, thin-walled continuously reinforced parts of complex shape are required.
 A particularly urgent need is for stiff demensionally stable joints for tubular
truss members in large space structures.  We propose a technique for producing such
MMC parts using very thin preforms, followed by pressure casting.  Phase I will evaluate
the feasibility of producing thin-walled tubular preforms  (0.005 in.) using spread
tows of graphite, then infiltrating the preform with an aluminum alloy using a specially
adapted presurized shell mold casting technique.  This work will form the foundation
for more complex joint structures, large components, and other alloys of aluminum
and magnesium.
.