Effect of rhenium addition on microstructure and mechanical properties of Ti−48Al−2Cr−2Nb alloys

The refractory metal rhenium (Re), with content of 0−2 at.%, was introduced into a typical γ -TiAl alloy of Ti−48Al−2Cr−2Nb (at.%) through vacuum arc melting. The effect of Re content on the microstructure and mechanical properties of the γ -TiAl alloy was investigated. The results show that the γ -TiAl− x Re alloy is composed of γ, α 2 , and β phases. As the Re content increases, the proportion of β phase increases, while the content and size of α 2 + γ lamellar structure decrease gradually. Furthermore, the compressive strength increases with increasing Re content. A maximum compressive strength of 2282 MPa is achieved for the γ -TiAl−2Re alloy. The γ -TiAl−2Re alloy exhibits a fracture strain of 36.7%, considerably higher than that of the γ -TiAl alloy (31.0%). Moreover, compared with the γ -TiAl alloy, the hardness and compressive strength of the γ -TiAl−2Re alloy considerably increase by 17.5% and 34.2%, respectively.