The effect of processing on the microstructure and tensile properties of a {gamma}-TiAl based alloy

Conference · Mon Feb 01 04:00:00 EST 1993

OSTI ID:10158088

Fuchs, G E

Compositional and microstructural control, and alloying additions have been the primary methods used to increase the low temperature ductility of TiAl-based alloys. However, very little has been done to characterize the effect of processing on ductile {gamma}-TiAl alloys. This study examines effect of processing on microstructure and properties of cast, wrought and powder metallurgy TiAl-based alloys with a similar nominal composition. The alloy was Ti-48Al-2Nb-2Cr (at. %). After processing, all of the samples were heat treated in the {alpha} + {gamma} phase field. Microstructures were characterized by optical, scanning electron and transmission electron microscopy. Tensile properties were evaluated in the temperature range 25--1000C in air. The powder processed alloys exhibited the highest strength and ductility at test temperatures up to 850C. All of the alloys exhibited similar tensile properties at 1000C. Examination of fracture surfaces indicated that tensile failure occurred by predominantly transgranular cleavage at temperatures below 700C. However, above 850C, significant plastic deformation was observed, particularly in the powder metallurgy samples. The inter-relationships of processing-microstructure-mechanical properties of Ti-48Al-2Nb-2Cr (at. %) will be discussed.

• Research Organization: Knolls Atomic Power Lab., Schenectady, NY (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC12-76SN00052
• OSTI ID: 10158088
• Report Number(s): KAPL--4737; CONF-920604--4; ON: DE93013221
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102
360103
ALUMINIUM ALLOYS
CHROMIUM ALLOYS
FAILURE MODE ANALYSIS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NIOBIUM ALLOYS
POWDER METALLURGY
PROCESSING
STRUCTURE AND PHASE STUDIES
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
TENSILE PROPERTIES
TITANIUM ALLOYS