γ→β phase transformation in Ti-42.9Al-4.6Nb-2Cr

This paper investigates the ??? phase transformation in a ?-solidifying ?-TiAl alloy (Ti-42.9Al-4.6Nb?2Cr, at. %), by means of SEM and TEM. The results show that part of ?/? phase interface is flat, and TEM observations reveal that stacking faults pairs sometimes act as the ?/? phase interface in isothermally compressed samples. The ??? phase transformation was a diffusional process, and was mainly governed by diffusion of Ti, Al and Cr. The occurrence of stacking faults pairs during ??? phase transformation at the ?/? phase interface was related to low SISF energy and sluggish Nb diffusion.

Automated summary

This study investigates the phase transformation in a β-TiAl alloy using SEM and TEM, finding that the process is diffusion-controlled, with flat interfaces and stacking faults pairs playing a role in some cases.