POSSIBLE FACTORS AFFECTING THE BRITTLENESS OF THE INTERMETALLIC COMPOUND TIAL .2. PEIERLS MANYVALLEY RELIEF

Models are proposed which account for the brittleness of the TiAl intermetallic. One of these models is based on the transformation of a glissile superdislocation into sessile non-planar configurations. The other is associated with the high Peierls stress that arises from directional bonds between Ti atoms. An adequate model should explain also the yield point temperature peak observed in TiAl. It has not yet been possible to choose an appropriate model on the basis of the experimental data available.