Why do titanium aluminide compounds have limited use despite their high-temperature strength?

The titanium aluminide intermetallic compounds, such as ${\text{Ti}}_3\text{Al}$ and $\text{TiAl}$, are recognized for their potential to replace nickel-based superalloys in aircraft engines due to their strength at elevated temperatures ranging from 600 to 870 °C (1,100 to 1,600 °F).1

However, despite these favorable high-temperature properties, their practical application remains limited primarily because of their low ductility.1