TUHH Open Research
Help
  • Log In
    New user? Click here to register.Have you forgotten your password?
  • English
  • Deutsch
  • Communities & Collections
  • Publications
  • Research Data
  • People
  • Institutions
  • Projects
  • Statistics
  1. Home
  2. TUHH
  3. Publication References
  4. Elemental segregation and o-phase formation in a gamma-tial alloy
 
Options

Elemental segregation and o-phase formation in a gamma-tial alloy

Publikationstyp
Conference Paper
Date Issued
2018-07
Sprache
English
Author(s)
Gabrisch, Heike  
Krekeler, Tobias  
Lorenz, Uwe  
Rackel, Marcus Willi  
Ritter, Martin  orcid-logo
Pyczak, Florian  
Stark, Andreas  
Institut
Betriebseinheit Elektronenmikroskopie M-26  
TORE-URI
http://hdl.handle.net/11420/11015
Journal
Materials science forum  
Volume
941
Start Page
741
End Page
746
Citation
Materials science forum 941: 741-746 (2018)
Contribution to Conference
10th International Conference on Processing and Manufacturing of Advanced Materials, THERMTEC 2018  
Publisher DOI
10.4028/www.scientific.net/MSF.941.741
Scopus ID
2-s2.0-85064087426
Titanium aluminides based on the L10 ordered γ-phase are promising structural lightweight materials for applications in aircraft engines. Typical compositions for γ-TiAl alloys lie in the range Ti-(44-48)Al (at.-%). For high creep resistance, a two-phase microstructure based on lamellar (α2+γ)-colonies is desirable that may be tuned towards better ductility by introducing pure γ-grains (near lamellar or duplex microstructure). γ-TiAl alloys are often alloyed with niobium for increased oxidation resistance and improved mechanical properties. HEXRD and TEM studies of the alloy Ti-42Al-8.5Nb revealed that the orthorhombic O-phase forms during annealing at 500-650°C. This orthorhombic phase has been known in Nb-rich, Al-lean, α2-based Ti-aluminides since the late 1980ies (Nb> 12.5 at.-%, Al< 31 at.-%) but the finding in γ-based alloys is new. TEM imaging showed that the O-phase is located within α2 lamellae of lamellar (α2 +γ)-colonies. O-phase domains and α2 phase form small columnar crystallites based in the α2 /γ interface. The columnar crystallites grow parallel to the [0001] direction of the α2 phase and appear as facets when observed along this direction. The evolution of domains and facets with annealing time and the chemical homogeneity of the phases are investigated. The results of STEM imaging show that O-phase domains form during annealing at 550 °C for 8hours or 168 hours. After 168 hours of annealing Nb segregations are observed by EDX mapping within O-phase domains. In comparison, no segregation of niobium is detected after 8 hours of annealing.
Subjects
EDX Mapping
Gamma-TiAl
O-phase
Segregation
Transmission Electron Microscopy
DDC Class
600: Technology
TUHH
Weiterführende Links
  • Contact
  • Send Feedback
  • Cookie settings
  • Privacy policy
  • Impress
DSpace Software

Built with DSpace-CRIS software - Extension maintained and optimized by 4Science
Design by effective webwork GmbH

  • Deutsche NationalbibliothekDeutsche Nationalbibliothek
  • ORCiD Member OrganizationORCiD Member Organization
  • DataCiteDataCite
  • Re3DataRe3Data
  • OpenDOAROpenDOAR
  • OpenAireOpenAire
  • BASE Bielefeld Academic Search EngineBASE Bielefeld Academic Search Engine
Feedback