The blades were actually perfect crystals, with either all the grain boundaries aligned, or no grain boundaries. This lets them run at higher temperatures witho

The blades were actually perfect crystals, with either all the grain boundaries aligned, or no grain boundaries. This lets them run at higher temperatures without melting, increasing efficiency. Pratt & Whitney appears to have developed most of the technology. https://www.americanscientist.org/article/each-blade-a-single-crystal https://www.americanscientist.org/article/each-blade-a-singl...