Regulating the Macro/Microstructure and Mechanical Properties of Ti2aln/Ti46al4nb1mo Composites Via Ultrasonic Treatment

In order to solve the problem of serious Al segregation and coarse Ti 2 AlN particles in as-cast TiAl composites, ultrasonic treatment was selected to further regulate the macro/microstructure and mechanical properties of Ti46Al4Nb1Mo alloy reinforced with Ti 2 AlN particles, and the effect of ultrasound treatment time on Ti 2 AlN/Ti46Al4Nb1Mo composites was investigated in this study. Results showed that when the ultrasonic treatment time increased from 0 to 120s, the shrinkage area was reduced, the shape of Ti 2 AlN particles changed from plate to ellipsoid and the coarse Ti 2 AlN particles with length more than 10 μm gradually became shorter (about 3 μm), especially with the ultrasonic treatment time at 120s, and the Al segregation region between the lamellar colony was also reduced. The reduction of shrinkage area, Ti 2 AlN and γ size resulted from the increase of nucleation supercooling and melt flow capacity by ultrasonic treatment. Compressive results showed that the maximum strength and strain were 2462MPa and 28.5% with ultrasonic treatment time for 90s and 120s, respectively, and the improvement of compressive properties was mainly due to the reduced size of Ti 2 AlN and γ phase