Status of investment cast gamma titanium aluminides in the USA

Investment casting of gamma titanium aluminide alloys has become the near-term process of choice for component manufacture. This is largely due to its near-net shape processing capabilities which allow cast gamma components to be manufactured at a lower cost when compared with wrought or powder methods. Casting processes have been developed that are capable of producing aerospace quality components as evidenced by several successful gas turbine engine tests using gamma castings. Recent advancements, including the use of Induction Skull Remelting (ISR) for gamma casting manufacture, have proven beneficial from both cost and quality standpoints. Additionally, extensive mechanical property data bases have been developed that give designers the tools and confidence they need to design gamma components. Many applications for cast gamma alloys exist, including commercial/military gas turbines, industrial gas turbines, missile/space systems and automotive systems. Mechanical properties and potential applications of investment cast titanium aluminide components will be discussed.