🚀 go-pugleaf

In article <1992Apr13.004026.2744@jupiter.sun.csd.unb.ca> akarpowicz@mta.ca writes:
>
>I want to thank everyone who responded to my questions on
>carbon/graphite composites, the discussion that followed was
>enlightening.
>
>I still do not know what is carbon foam.    
>
>Adam

Either do I, but that reminds me of an question I've had for a long
time: why isn't there a structural steel foam material?  Seems to me
it should be very strong and cheap, if there's a good way to make it.
Is the problem simply one of how to keep bubbles from rising?
Clearly, zero-gee ought to help, but I would suppose someone could
invent some way to make such a material!  One way would be to inject
bubbles at high pressure when the steel is at a viscous temperature,
and then rotate it while it does the remaining cooling.  Once the
outside of the "ingot" hardens, we don't care much that the pressure
inside goes negative; in fact that could be an advantage.
  Other ideas might include using some sort of refactory mesh to hold