Grain Refinement of a gamma-TiAl Alloy Through Isothermal Forging and Heat Treatment

Journal Article · Thu Mar 11 00:00:00 EST 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3377875· OSTI ID:21371694

Heshmati-Manesh, S; Bahmanpour, H ^[1]

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1. School of Metallurgy and Materials Engineering, University of Tehran, Tehran, PO Box 14395-553 (Iran, Islamic Republic of)

Effect of initial massive type structure of a gamma-TiAl based alloy on its hot deformed and stabilized microstructure was investigated. A gamma alloy with composition of Ti-47Al-12Nb-0.5Si was subjected to rapid quenching from alpha phase field. The quenched sample was deformed at high temperature. Further post deformation heat treatment was conducted to stabilize the as-deformed structure. It was shown that Nb and Si have important roles in grain refinement of the final product. Presence of niobium in the alloy made the diffusion controlled eutectoid reaction sluggish and assisted the formation of massive type gamma phase (gamma{sub m}) by rapid cooling from alpha phase field. Silicon addition assisted the microstructural refinement by forming hard and finely dispersed titanium silicide particles. These particles act as preferred sites for dynamic recrystallization during hot deformation. Massive gamma phase tends to deform uniformly and decompose to equilibrium phases after final heat treatment and results in a very fine grained microstructure.

• OSTI ID: 21371694
• Journal Information: AIP Conference Proceedings, Vol. 1217, Issue 1; Conference: ICAMN-2007: International conference on advancement of materials and nanotechnology, Langkawi, Kedah (Malaysia), 29 May - 1 Jun 2007; Other Information: DOI: 10.1063/1.3377875; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COOLING
CRYSTAL STRUCTURE
DEFORMATION
DIFFUSION
FORGING
GRAIN REFINEMENT
HEAT TREATMENTS
MICROSTRUCTURE
NIOBIUM
QUENCHING
RECRYSTALLIZATION
SILICON ADDITIONS
TITANIUM ALLOYS
TITANIUM SILICIDES
ALLOYS
ELEMENTS
FABRICATION
MATERIALS WORKING
METALS
REFRACTORY METALS
SILICIDES
SILICON ALLOYS
SILICON COMPOUNDS
TITANIUM COMPOUNDS
TRANSITION ELEMENT ALLOYS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS