https://ntrs.nasa.gov/archive/nasa/c...9950025352.pdf
https://en.wikipedia.org/wiki/Metal-..._embrittlement
https://www.faa.gov/documentLibrary/...r/AC_43-4B.pdf
3.2.5 Titanium. Titanium is prone to cause severe corrosion of adjacent parts through galvanic corrosion. Titanium parts may be galvanically isolated from adjacent parts through barrier coatings or films. Frequent inspection for degradation of these barrier films and inspection for corrosion of adjacent parts is recommended. Contact with zinc and cadmium-plated parts can promote cracking of the titanium.