Controlling Atomic Movement for Material Strength

Materials only deform because they are literally full of defects called dislocations. It is actually wild,

but metal bends because these atomic glitches are sliding around inside the lattice.

If you want to make something strong, your only job is to stop that movement. It is like traffic

control for atoms. You can block them with grain boundaries, mess up their path with extra solute

atoms, or just beat the material up until it gets work hardened. FCC crystals are

chill and ductile, but HCP is brittle and will snap. Basically, strength is just

how hard you make it for atoms to slip.