Study On Selective Laser Melting Forming Of Ti₂AlNb-based Alloys

With the rapid development of aerospace technology,the service properties and processing performance of high-temperature structural materials are increasingly required.After more than30 years,the traditional processing technology of Ti₂AlNb-based alloy with excellent comprehensive performance is gradually mature.It is expected to replace the current Nickel-based superalloy in the range of 650?to 800?and be applied in the aero-engine blade and some other occasions.However,the traditional manufacturing method of multi-curved blade structure is rather difficult.Additive manufacturing technology,especially selective laser melting(SLM)technology,provides a novel way to solve this problem.In this paper,Ti-22Al-25Nb,one of typical Ti₂AlNb-based alloy was chosen as the research object.And the whole process of selective laser melting of Ti-22Al-25Nb alloy was implemented,including alloy melting,powder fabrication and SLM forming.Subsequently,the microstructure and mechanical properties of as-cast alloy,the microstructure and high-temperature phase transitions of alloy powders,the microstructure and mechanical properties of SLM parts,the influence of SLM process parameters on mechanical properties,the effect of room temperature deformation behavior on microstructure of SLM parts and the feasibility verification of SLM forming of alloy parts were studied in detail.Eventually,the optimal SLM process parameters were selected to complete the SLM forming on blade part models with or without supported structure,and the effect is very satisfying.In conclusion,this study involves all the steps of SLM process,including as-cast alloy fabrication,powder preparation,SLM forming process,experimentation and characterization,and component forming.Undoubtedly,this study can provide ideas and references for the application and development of Ti₂AlNb alloy in the future.