ATI High Temperature Titanium Alloys for Aerospace Applications

The attractive combination of good mechanical behavior and relatively low density has resulted in titanium alloys comprising 15 to 25% (by weight) of modern jet engine components in the fan, compressor and nozzle sections. Typically, titanium jet engine alloys are selected from the group of near alpha and alpha-beta titanium alloys exhibiting good elevated temperature strength, creep resistance and fatigue life. Improving the mechanical behavior of these alloys is a critical component for advancing engine performance. Legacy titanium alloys for jet engine applications include Ti-5Al-2Sn-2Zr-4Mo-4Cr, Ti-6Al-2Sn-4Zr-2Mo-0.1Si and Ti-4Al-4Mo-2Sn-0.5Si. Experiments conducted at ATI have identified several new alpha-beta titanium alloy compositions which exhibit significantly improved elevated temperature strength and creep resistance. This presentation will focus on the effects of chemistry and heat treat conditions on the microstructure and resulting elevated temperature properties of two of these new aerospace titanium alloys: ATI Titan 171™ and ATI Titan 42™.