Analysis of grain growth in a two-phase gamma titanium aluminide alloy

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-997-0225-0· OSTI ID:484845

Seetharaman, V ^[1]; Semiatin, S L ^[2]

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1. UES Inc., Dayton, OH (United States). Materials and Processes Div.
2. Wright Lab., Wright-Patterson AFB, OH (United States). Materials Directorate

Microstructure evolution during annealing of a wrought near-gamma titanium aluminide alloy, Ti-45.5Al-2Nb-2Cr (at. pct), in the temperature range 1,200 C to 1,320 C was investigated. The mean grain size of the alpha phase as well as the volume fraction and size of the gamma particles were evaluated as a function of annealing temperature and time. Isothermal annealing at temperatures above the alpha transus, T{sub {alpha}} = 1,300 C, led to rapid grain growth of the alpha phase, the kinetics of which could be described by a simple power-law type expression with a grain growth exponent p = 2.3. Alpha grain growth was significantly retarded during annealing at subtransus temperatures (1,200 C {le} T {le} 1,300 C) by the pinning influence of gamma-phase particles. Limiting grain size values predicted by computer simulation models applicable for high-volume fractions of precipitates/particles were in good agreement with experimental findings. The kinetics of alpha grain growth in the presence of gamma particles were analyzed, and the results showed that a grain growth exponent of p {approx} 2.6 could satisfactorily account for the experimental results.

• Sponsoring Organization: Department of the Air Force, Washington, DC (United States)
• OSTI ID: 484845
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 4 Vol. 28; ISSN 1073-5623; ISSN MMTAEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ANNEALING
CHROMIUM ALLOYS
COMPUTERIZED SIMULATION
GRAIN GROWTH
GRAIN SIZE
INTERMETALLIC COMPOUNDS
KINETICS
NIOBIUM ALLOYS
TEMPERATURE RANGE 1000-4000 K
TITANIUM ALLOYS