Strain-Induced Recrystallization of Tial

Abstract

ABSTRACTTransmission electron microscope investigation of extruded and rolled XD™ titanium aluminide sheet has shown the development of recrystallized TiAl regions adjacent to grains which exhibit submicron scale TiAl twins. Detailed diffraction analysis confirmed that the TiAl twins were separated by a layer of Ti3Al. This is consistent with previous observations of the microstructure of extruded XD™ titanium aluminide. In the extruded material, however, the scale of the twins was larger, but the extent of the recrystallized region was smaller. The evidence suggests that the recrystallization of the TiAl regions may result from the impingement of twins from adjacent grains.