Oxygen sneaks into titanium, making it brittle

Invading atoms multiply weaknesses in the tough metal’s structure

Titanium lattice

ELBOWING IN  Oxygen atoms (black arrows) invade titanium, forcing the metal atoms out of their regular atomic structure. The blue arrows indicate where those titanium atoms would have been in the absence of oxygen.

Qian Yu

A dash of oxygen can bring superstrong titanium to its knees.