Densification behavior of high Nb containing TiAl alloys through reactive hot pressing

Densification behavior of high Nb containing TiAl alloys through reactive hot pressing was investigated. The results showed that the density of the sample hot pressed at 1400°C could reach a near full density of 98.37%. However, the densification abnormality was observed at 1500°C. The diffusion of elemental Nb during microstructural evolution is an important aspect affecting densification, which will form pore nests. With the increase of hot pressing temperature, the diffusion of Nb becomes more adequate. HIP (Hot isostatic pressing) treatment can only decrease porosity to some extent, but cannot eliminate it completely.