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Composition dependence of the massive transformation from. alpha. to. gamma. in quenched TiAl alloys

Journal Article · · Scripta Metallurgica et Materialia; (United States)
;  [1]
  1. Dept. of Materials Science and Engineering, Univ. of Cincinnati, Cincinnati, OH (US)

Alloys based on the intermetallic compound TiAl have been of much interest in recent years as lightweight, structural materials for elevated temperature aerospace applications. The most promising alloys are based on the Ti-48 Al composition with ternary or quarternary additions and with the two-phase Ti{sub 3}Al + TiAl ({alpha}{sub 2} + {gamma}) lamellar microstructure. In low Al alloys, the lamellar structure has been suggested to be produced by the reaction {alpha} {yields} {alpha}{sub 2} {yields} {alpha}{sub 2} + {gamma}, involving initial formation of stacking faults. More recently, it has been suggested that this mechanism is operative till {approx} 42 Al, whereas at higher concentrations the lamellae are formed directly from the {alpha} and subsequently the {alpha} orders to {alpha}{sub 2} to produce the same morphology of lamellae as observed at lower concentrations.

OSTI ID:
7177429
Journal Information:
Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 27:1; ISSN SCRME
Country of Publication:
United States
Language:
English