About this Abstract | 
  
   
    | Meeting | 
    2022 TMS Annual Meeting & Exhibition
       | 
  
   
    | Symposium 
       | 
    Phase Transformations and Microstructural Evolution
       | 
  
   
    | Presentation Title | 
    On the Precipitation Behavior of γ-TiAl from a Supersaturated βo-TiAl Matrix in an Intermetallic Ti-44Al-7Mo (at.%) Alloy | 
  
   
    | Author(s) | 
    Gloria  Graf, Christoph  Gammer, Simon  Fellner, Johanna  Byloff, David  Holec, Helmut  Clemens, Petra  Spoerk-Erdely | 
  
   
    | On-Site Speaker (Planned) | 
    Gloria  Graf | 
  
   
    | Abstract Scope | 
    
As lightweight materials with excellent high-temperature properties, intermetallic γ-TiAl based alloys have recently become well established in the aviation industry. In this work, the focus lies on the Ti-44Al-7Mo (in at.%) alloy. Molybdenum, as an alloying element, strongly stabilizes the β/βo phase and yields a (βo + γ) phase-field region at ambient temperatures. Consequently, the precipitation behavior of γ from an ordered βo matrix can be investigated, which is not possible for conventional alloys and therefore not yet well understood. Previous differential scanning calorimetry and high-energy X-ray diffraction investigations raised the questions whether the precipitation of γ-TiAl is preceded by the formation of an intermediate phase and whether the precipitate’s interface type changes during the process. With high-resolution transmission electron microscopy and ab-initio calculations it was proven that the interfaces are first coherent and slowly become incoherent with increasing precipitate radius. No intermediate phase is formed. | 
  
   
    | Proceedings Inclusion? | 
    Planned:  | 
  
 
    | Keywords | 
    High-Temperature Materials, Phase Transformations, Other |