Corrosion & Environmental Degradation		Table of Contents
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	Titanium · Titanium metal resists corrosion by forming of a passivating surface oxide. The TiO2 film is resistant to sea water and is stable in the similar environment of the human body. Its corrosion resistance and high strength to weight ratio makes it attractive for orthopedic implant use. · The material resists pitting in electrolytes such as FeCl3 and CuCl2 that readily cause pitting corrosion in other metals. Surface reactions with these salts increase the passivity of the titanium surface. · Contact with a corroding metal that is liberating hydrogen atoms to the electrolyte permits rapid hydrogen adsorption by the titanium, and hydrogen embrittlement. · Surface contamination with iron particles permits local corrosion at these particles and pitting of the titanium. These pits will act as stress concentrators and promote crack formation under mechanical stresses. · Commercial titanium alloys such as Ti - 6% Al - 4% V have the same corrosion resistance and superior mechanical properties to the pure material. · Titanium is not resistant to corrosion in HCl, HF, or dry Cl gas. · Titanium acts as a "getter" for ambient gasses at high temperature.Joining by welding must be done in an inert atmosphere (TIG welding) if brittle and corrosion prone welds are to be avoided.