dietz%USC-CSE@USC-ECL.ARPA (04/20/84)
Rockets, radiators, etc. work best at high temperatures. What substance has the highest known melting point (at reasonable pressures)?
DOUG@JPL-VLSI.ARPA (04/23/84)
From: Doug Freyburger <DOUG@JPL-VLSI.ARPA>
It stricks me that diamond has the highest melting point. There are
chemistry problems with it for rockets, though. There is a metal, Hafnium I
think, that's up in pretty high range, too.
Doug
------dms@fluke.UUCP (Dave Sherman) (05/01/84)
Your diamond rocket may have a high melting point but it has
another problem: It'll burn. It seems to me some Frenchman
demonstrated that with a burning glass back in the days of the
sun king.
---David
...{decvax!microsof,uw-beaver,allegra,lbl-csam,ssc-vax}!fluke!dms hutch@shark.UUCP (05/02/84)
<tap tap tap CLINK (OH NO)> As any jeweler who is a diamond-cutter can tell you, the diamond is a very hard crystal but it is also very brittle. It shatters very easily. The tensile strength of a material has definite bearing on whether it would be useful as a liner for rocket engines. Diamonds, besides burning, would shatter. Hutch
eder@ssc-vax.UUCP (05/17/84)
17 May 1984
Many solid rocket nozzles are made of a carbon-carbon composite, for
example the Star-48 motor used on PAM-D's and the SRM-1 motor used on the
IUS. These are made by forming a graphite-epoxy structure, then heating
it until the epoxy chars, leaving carbon fibers reinforced by carbon
particles.
The composition of this nozzle is nearly 100% carbon, which is the
same as diamond. The nozzles are used because they are strong for their
weight at the extremely high temperatures they operate at.
The nozzle throats (the narrowest part) DO erode during the motor
operation, but it is hard to find anything that won't do that at
those temperatures (6100 F for a Star-48).
Dani Eder / Boeing Aerospace / ssc-vax!eder / (206)773-0570