3
$\begingroup$

I am researching on how to make a small jet engine, and trying to figure out the materials for rotor and stator blades just after the combustion chamber so that they can hold up to the temperatures they will encounter.

I'm looking for cast repeatable shaped blades and trying to figure out what kind of forge or kiln to use.

My questions:

  • Should the blades vanes be nickel alloys or can they be ceramic so that dilatation won't make them interfere with adjacent parts?

  • Will the ceramic be too brittle?

Improve this question
$\endgroup$
2
  • 2
    $\begingroup$ It depends a lot on the size of the engine and what ceramic you are planning to use. Are we talking about model plane jet engine size? There are a lot of ceramics that can easily endure the heat in a jet engine, however their tensile strength could be an issue. It could work, as miniturizing tends to put less proportional tensile stress on the components. Then again you might have a problem with foreign objects entering the engine... BUT without knowing the size of the planned engine and the planned components it's impossible to do the math if it will work or not. $\endgroup$
    – Adwaenyth
    Apr 13, 2017 at 6:23
  • 2
    $\begingroup$ It also depends on the temperatures you plan to go to. Large commerical and military engines push the limit on temperature to get every last pound of thrust and/or every last point of fuel efficiency. As such, they are always right up against the limit of the material. If you are willing to sacrifice some thrust or fuel efficiency, your job will be a lot easier. $\endgroup$
    – Daniel K
    Apr 13, 2017 at 11:32

2 Answers 2

Reset to default
4
$\begingroup$

Yes, according to the journal article "Manufacturing a Ceramic Turbine Rotor for a Compact Jet Engine," Leicht et al, J. Turbomach. Aug 2023, 145(8): 081009.

As a proof of concept, an additively manufactured drop-in replacement alumina turbine rotor was produced for the JetCat P400 small-scale engine in a manner that was cost-effective, timely, and potentially scalable for production. This compact engine was used to demonstrate that a cost-effective ceramic turbine could be manufactured. At the time of publication, the desired ceramic material, silicon nitride, was not available for additive manufacturing.

The JetCat P400 weighs about 8 lb and has a max thrust of about 90 lbf.

Similarly, Fraunhofer is making silicon nitride rotors rated for 1400ºC and 90,000 RPM for small turbines, albeit for power generation not airplane thrust. Fraunhofer agrees that tensile strength and bending strength is a challenge for brittle ceramics.

Improve this answer
$\endgroup$
-1
$\begingroup$

I can't speak for all engines, but GE has been testing ceramic blades in their LEAP engines. Here is their report on it.

Improve this answer
$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .