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evanc3 t1_irpejoo wrote

Plenty of materials that can do this, the trick is to get one that doesn't creep over time because the blade tips are remarkably close to the engine wall (tip clearance)

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slater_just_slater t1_irq2fgg wrote

Creep is why most 1st stage turbine blades are single crystal. Fun fact, single crystal blades are "grown" not cast.

They are also the most boring thing ever to look at under a metallograph.

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evanc3 t1_irq2u47 wrote

Still blows my mind!

But yeah I can imagine lol

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slater_just_slater t1_irq4gst wrote

What is interesting is that it's the same principle to how single crystal silicone is grown for microchip substrates. However the blades are hollow.

Since they have no grain structure, nothing responds to an acid etc, on a metallograph it's just a white blob.
They do have a thermal barrier coating (TBC) One of my jobs as a process engineer at Rolls Royce was the TBC coating. If you are bored here is a link about it.

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evanc3 t1_irq4nd0 wrote

I've actually worked in both industries! Very cool link though, I do thermal for aerospace currently but haven't come across these.

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