I am doing a project on the physics of the spaceX raptor engine. I believe it is made out of a certain type of inconel alloy. I want to understand why this alloy has the properties that it does, but I don't know anything about materials science. I am a senior physics major.

I am looking for a good introductory text/texts that will give me insights into the properties of inconel so I can explain why it doesn't flare at high temperature+pressure in my paper.

Any other advice would be welcome as well. Thanks for the help!

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    $\begingroup$ The inconel article in wikipedia might give you a start. $\endgroup$
    – Ed V
    Jan 14, 2021 at 23:28
  • $\begingroup$ The Wiki article is a start , I would not rely on it if you must have correct info ,I see Specialty Metals acquired Inco , Huntington and Wiggins. Inco developed most info ( not Wiggins) ,they did have a connection with Wiggins. $\endgroup$ Jan 15, 2021 at 1:36

1 Answer 1


There are several Inconels , the basic one is 600. Because the Inco and Huntington divisions are now gone or acquired ,it would be difficult to get literature . But they produced copious amounts , you may be able to find some ; I have about a 6" stack of brochures I have been too lazy to discard. American Society for Metals Handbooks should be easy to find ( there are several issues). ASM is a common and comprehensive source. What do you mean "Flare" ?

The 600 Inconels do not age harden; The 700 Inconels do age harden. All have good strength and oxidation resistance at high temperatures . Some useful above 2000 F. If you are talking about a rocket ,I guess you do not need blade and vane alloys ( for turbines). 800 and 900 are Incoloys ; 400 and 500 are Monels
Addenda Looking at SpaceX info they are using something like Inconel 750 ( formerly X , and X750 ), so it is age hardened for strength due to pressure in the engine. Supposedly they have a modification named SX 500 . Apparently by "flare" they means rapid oxidation because of the oxygen in the engine , but they do not explain.

  • $\begingroup$ This is useful thanks. I assumed that flare must have been a technical term, but I guess not. I think it probably means that in the combustion chamber, the oxidizer and metal oxidize and ablate so rapidly that it is essentially combustion? $\endgroup$
    – fredc1
    Jan 15, 2021 at 7:34
  • $\begingroup$ I think "flare" was created by someone in the SpaceX public relations department ; no reflection on SpaceX impressive accomplishments. Any turbine hot stage alloy would resist rapid oxidation in the rocket although high oxygen partial pressure can cause various problems. As NASA found out when they made the poor decision to use 100% O in the capsule and killed 3 astronauts on the ground ( see Gus Grisom , et.al.) $\endgroup$ Jan 15, 2021 at 15:59
  • $\begingroup$ Ya, I'm pretty sure there is a certain section of the engine that combusts a super oxygen rich mixture and uses the hot exhaust to drive a turbine that pressurizes the combustion chamber. $\endgroup$
    – fredc1
    Jan 15, 2021 at 18:44

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