Manufacturing a TiAl alloy by high-energy ball milling and subsequent reactive sintering

A TiAl alloy was fabricated by high-energy ball milling and subsequent reactive sintering from the mixed powders of Ti and Al. High-energy ball milling produced a kind of particular composite powders with an extremely fine alternative Ti and Al lamella structure. The composite powders not only possessed good consolidation and densification characteristics, but also resulted in the augment of nucleation rate of α and γ titanium aluminides during solid-phase reactive sintering. After a series of processing, pressing, degassing, extrusion, and sintering, the resultant TiAl alloy presented high relative density and refined grain sizes of (α₂ + γ) lamella and γ phases. The compressive yield strength of the sintered TiAl reached 600 MPa at 800°C.