Nickel Superalloy Turbine Blade

Turbine blades are made of superalloys that contain more than 50% of nickel and allow solidification of the whole blade as a single crystal (find out more about why here). 

The image shows an electron microscope image of a single crystal. You can see a lot of squares (that are actually cubes) that sit very closely together, but are separated from each other by material with a different shade of grey. These cubes have a different atomic arrangement compared to the surrounding material. 

In fact, the cubes have an ordered structure, which means that certain elements will always sit in specific locations. Take a look at the diagram below. The structure on the right shows the ordered cubes where the nickel and aluminium sit on specific sites (the aluminium atoms on the corners and the nickels on the faces). The rest of the material has Nickel and aluminium atoms randomly distributed among them and looks like the cube on the left.This ordering in the structure provides additional strength to the metal, making it able to withstand the high temperatures and stresses in the turbine.