Book 27, Question 114
Why are jet engine blades grown as one crystal?
Inside a jet engine, hot gases are hotter than the melting point of the metal.
The blades spin quickly and endure heat and force. Ordinary metal has many tiny crystals, and the boundaries between them are weak spots where blades slowly stretch. Engineers grow special blades from just one crystal of nickel alloy, so there are no weak boundaries. Tiny cooling holes also protect them.