Structure Change of TiAl during Creep in the Intermediate Stress Range

Creep behaviour of two-phase lamellar TiAl: Crystal plasticity modelling and analysis

“…In past few decades, experiments were conducted to identify key roles of microstructure on creep resistance of TiAl alloys. Systemic analyses were performed on bulk materials of single TiAl phases [8,9], combined (α 2 Ti 3 Al+TiAl) multi-phases with lamellar structures, known as PST-TiAl [10][11][12], and polycrystals of single and multi-phase lamellar grains [12][13][14]. It was found that the creep responses of single TiAl phases and multi-phase combinations were significantly different, which comes from different inherent boundaries.…”

Microstructural evolution during creep of single-phase gamma TiAl

“…Published values of Q creep range from 192 to 700 kJ/mol, [5][6][7][8][9][10][11] and n has generally been measured to be much closer to 8 than 4.5. [6,15,16] In the absence of a pure metal description of power-law creep, an alternative method for modeling the creep behavior of ␥-TiAl is needed. Moreover, detailed investigation of the intermediate temperature creep behavior of single-phase ␥-TiAl has led to the conclusion that a microstructural steady state is not attained, [15] and transmission electron microscopy (TEM) observations have MIN shown that the microstructure evolves throughout creep.…”