What are the advantages of titanium alloys for aerospace use?

Titanium offers unique advantages: High strength-to-weight ratio - density 4.5 g/cm3 (between aluminum and steel), strength comparable to steel; Excellent corrosion resistance - no galvanic corrosion with carbon composites (unlike aluminum); High temperature capability - useful to 300-600C depending on alloy; Low thermal expansion - matches composite parts better than aluminum; and Biocompatibility - no toxicity concerns. Primary aerospace applications: Engine components (compressor blades, discs), Composite-metallic interfaces, Landing gear, Fasteners for composite structures, and High-temperature zones. Disadvantages: High cost (10-15x aluminum), Difficult to machine (poor thermal conductivity, work hardening), Requires special processing (reactive with oxygen at high temperature), and Limited forming capability. Titanium alloys include alpha (Ti-5Al-2.5Sn), alpha-beta (Ti-6Al-4V most common), and beta alloys.