(robert arndt) wrote in message . com...
As I've mentioned several times, not with the materials they had
available in 1945. Repeating this false assumption does not make it
suddenly become true.

At a "mere" Mach 6, the X-15 skin reached 650 to 700 degrees C, in a
minute and a half of powered flight. This would have happened to the
Sanger several times per mission, with a skin that didn't have the heat
resistance of the X-15's.

You obviously don't know much about the SS Technical Branch and their
work in metallurgy. Documents recovered at Gottingen and Volkenrode
indicate that between 1943-44 the SS were experimenting with a
frictionless metal called "Luftschwamm" (Aerosponge) that could
withstand 1000 degrees Centigrade.

This is no bizzare idea.

I first came across foamed metal while working in Germany in 1992. It
was foamed aluminium used in this case to absorb the energy of car
crash.

Very complicated foams of Aluuminium, Titanium, Nickel and refractory
alloys are possible as sheets or moldings with smooth finishes.
Foaming can be by inert gas but more likely by foaming agents like TiH
or ZiH.

They can be injection molded or formed into sheets. All sorts of
connection methods are possible including welding.

There is a review of the technolgy he
http://nic.sav.sk/ummsjk/main_act.htm

They are at the point where Volvo are using Stainless steel laminates
with metal foam/fiber center cores for use in production cars.

Consider that aircraft skins in WW2 were reaching 5mm thick (B29
bomber)

As a thought experiment immagine a stainless steel laminate consisting
of 0.25mm stainless steel on either side with a 4:1 foamed core. I
would have the same thickness as the aluminium and the same density
but would have much higher stiffnes and strength and would provide
usable strength up to 750C to 1000C for refractory allys. I foaming
of Molydenum becomes possible perhaps 2000C.

The Tinadur alloy Junkers used on the Jumo 004B series Jet was of
Ti,Ni,Cr,Fe and would have leant itself nicely to foaming with TiH.

The heat isolating poperties would be substantial. At least 20 times
that of the equivalent weight of steel.

I imagine that a SSTO, (Single Stage to Orbit) vehicle could be made
in foamed metal in which the structure serves to:
1 Provides Integral Heat Isolating Tankage for Cryogenic Propellants.
(I.E. no
2 Provides Heat Shielding.
3 Provides Strength, Stiffness with a minium of internal structure.