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Title: Properties of two-phase intermetallic (Ti, Nb){sub 3} (Al, Si) + (Ti, Nb){sub 5} (Si, Al){sub 3} P/M bulk and sheet material

Journal Article · · Acta Materialia
; ;  [1];  [2];  [3]
  1. GKSS-Forschungszentrum, Geesthacht (Germany)
  2. TU Hamburg-Harburg (Germany)
  3. Plansee Aktiengesellschaft, Reutte (Austria). Technology Center

Intermetallic Ti-based alloy powder with nominal composition Ti 23.5Al5.5Si 10 Nb(at.%) was produced by argon gas atomization. This dual phase alloy is composed of the {alpha}{sub 2}-(Ti, Nb){sub 3} (Al,Si)-matrix phase and a eutectic mixture of {alpha}{sub 2}-(Ti, Nb){sub 3}(Al, Si) + {xi}-(Ti, Nb){sub 5} (Si, Al){sub 3}. The powder was compacted by hot isostatic pressing, subsequently hot rolled into sheets, and heat treated. The microstructures of the HIPed compacts and of the sheet materials were metallographically characterized and correlated with tensile properties at temperatures between 20 and 1,000 C. Due to networks of the brittle {xi}-silicide phase, the HIPed state showed no ductility at 20 C. Break-down of the silicide network during rolling led to an improved ductility at 20 C. After post rolling annealing, the yield strengths at 20 and 700 C were between 750--490 MPa and 700--420 MPa for specimens taken parallel and perpendicular to the rolling direction, respectively. These values are considerably higher than those reported for {gamma}-TiAl sheets. At 1,000 C the sheet material could be superplastically deformed.

OSTI ID:
554107
Journal Information:
Acta Materialia, Vol. 45, Issue 10; Other Information: PBD: Oct 1997
Country of Publication:
United States
Language:
English