Development status and application progress of Ti₂AlNb alloys for aero-engines

As a new type of high-temperature lightweight structural material, Ti₂AlNb alloy is regarded as one of the most promising candidates to replace nickel-based superalloys for significant weight reduction in critical high-temperature components of aero-engines. At present, the development of Ti₂AlNb alloy has reached a mature stage, and its application in aero-engines is accelerating. Therefore, the demand for transitioning the properties of the material from laboratory scale to actual structural service performance is becoming increasingly urgent. This paper systematically reviews the research status and development of the application performance of Ti₂AlNb alloy in aero-engines. Based on a summary of the development progress of the alloy, material selection analysis, and current application status in engines, the application pathway of “static components first, then rotating components” and its typical potential application objects are identified. Furthermore, the requirements and key research tasks for evaluating the structural application performance of Ti₂AlNb alloys are systematically outlined from the perspectives of engine structural integrity requirements, needs for strength and life analysis methods and tools, and the establishment of a comprehensive material application evaluation system. Subsequently, taking the combustor casing structure as an example, the current research status of the structural application performance evaluation of Ti₂AlNb alloys in aero-engines is elaborated in detail. Finally, based on the current research progress, future directions for advancing the material selection and structural application performance evaluation of Ti₂AlNb alloys are proposed: future efforts should focus on real engine service conditions, systematically conduct performance evaluations under multi-factor coupled environments, establish quantitative microstructure-property correlation models and develop material-structure-performance integrated design methods, so as to provide solid support for the engineering application of Ti₂AlNb alloys in critical components such as combustor casings.