J Mater Sci Technol ›› 1993, Vol. 9 ›› Issue (6): 449-457.

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Microstructure and Mechanical Properties of TiAl-based Alloy

Zhongjie PU Jiandong SHI Dunxu ZOU Zengyong ZHONG Central Iron and Steel Research Institute,Beijing,100081,China   

  • Received:1993-11-28 Revised:1993-11-28 Online:1993-11-28 Published:2009-10-10

Abstract: Two phases gamma titanium aluminide alloy,Ti-46.5Al-2.5V-1Cr.was investigated to characterize microstructures and to define the microstructure/mechanical property relationship.Many kinds of microstructure of gamma and α_2 phases were obtained by heat treatments in the α+γ,α_2+γ and α fields.The effects of microstructure on tensile properties,fracture toughness and J-R resistance curve at room temperature,were systematically studied.The experimental results showed that the microstructure had a strong effect on mechanical properties,The duplex microstructure produced by heat treatment at 1250℃×4 h with controlled cooling resulted in the highest ductility of 4.8% tensile elongation,low fracture toughness and crack growth resistance.The fully lamellar microstructure produced by heat treatment in the α field having large grain sizes resulted in the highest fracture toughness but the lowest ductility.

Key words: microstructure, mechanical property, TiAI alloy