Accession Number:

ADA279254

Title:

The Development of a Super-alpha2 Titanium Aluminide Alloy Consolidated by Rapid Omnidirectional Compaction

Descriptive Note:

Final rept.

Corporate Author:

ARMY RESEARCH LAB WATERTOWN MA MATERIALS DIRECTORATE

Personal Author(s):

• Wang, Wego
• Wells, Martin G.

Report Date:

1994-03-01

Pagination or Media Count:

45.0

Abstract:

Six super-alpha 2 titanium aluminide pancakes were produced by rapid omnidirectional compaction of prealloyed Ti-25A1-1ONb-3V-1Mo at powder. The beta-transus temperature was found to be about 1,090 deg C 1,990 deg F. The alloy was heat-treated with four different schedules to develop various structure combinations of alpha 2 and beta, and followed by a series of microstructural analyses and mechanical property determinations. The highest ultimate tensile and yield strengths attained at room temperatures were 1,174.9 and 977.7 MPa 170.4 and 141.8 ksi, respectively. However, the elongation was less than 2. The alloy also showed good stress rupture resistance. It was observed that, under otherwise similar conditions, ductility increased with the aspect ratio of the alpha 2 phase but the tensile strength is inversely related to the aspect ratio. During the tensile and stress rupture tests, multiple transverse cracks nucleated in the longitudinal direction on the specimen surface and within the specimen simultaneously. Titanium aluminide, Rapid omnidirectional compaction, Fracture mechanism.

Descriptors:

• *ALLOYS
• *TITANIUM ALUMINIDE
• TEST AND EVALUATION
• RATIOS
• TEMPERATURE
• MECHANICAL PROPERTIES
• TENSILE STRENGTH
• MICROSTRUCTURE
• MATERIALS
• RUPTURE
• HEAT
• YIELD STRENGTH
• DUCTILITY
• YIELD
• COALESCENCE
• BOUNDARIES
• SURFACES
• ROOM TEMPERATURE
• PHASE
• FINES
• OMNIDIRECTIONAL
• TRANSVERSE
• ASPECT RATIO
• ELONGATION
• DETERMINATION
• POWDERS
• RESISTANCE
• CRACKS
• SITES
• MORPHOLOGY
• STRUCTURES
• NUCLEATION

Subject Categories:

• Inorganic Chemistry
• Properties of Metals and Alloys
• Manufacturing and Industrial Engineering and Control of Production Systems
• Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE