Monotonic and Transient Creep Experiments for Single Phase Gamma TiAl at Intermediate Temperatures

Abstract

ABSTRACTMonotonie creep experiments (constant stress and constant temperature) of a single phase γ Ti47Al51Mn2 were conducted within a temperature region where the yield stress anomaly is observed (500°C - 600°C). The creep strength was found to have a normal temperature dependence. In addition to the monotonie creep experiments, temperature change experiments were performed. The creep activation energy obtained by the transient experiments was found to be significantly lower than that obtained from the monotonie experiments. TEM observations indicate that the microstructure evolves throughout creep, and no evidence of the formation of subgrains was observed. Instead, the mobility and the multiplication of ordinary dislocations were found to play a dominant role in intermediate temperature creep of single phase γ TiAl.