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

摘 要：<正> Two phases gamma titanium aluminide alloy,Ti-46.5Al-2.5V-1Cr.was investigated to characterizemicrostructures and to define the microstructure/mechanical property relationship.Many kinds ofmicrostructure of gamma and α₂ phases were obtained by heat treatments in the α+γ,α₂+γ and αfields.The effects of microstructure on tensile properties,fracture toughness and J-R resistancecurve at room temperature,were systematically studied.The experimental results showed that themicrostructure had a strong effect on mechanical properties,The duplex microstructure produced byheat treatment at 1250℃×4 h with controlled cooling resulted in the highest ductility of 4.8% tensileelongation,low fracture toughness and crack growth resistance.The fully lamellar microstructureproduced by heat treatment in the α field having large grain sizes resulted in the highest fracturetoughness but the lowest ductility.

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