Decomposition of [011]superlattice dislocations in cyclically deformed TiAl polysynthetically twinned crystals

Decomposition of [011] superlattice dislocations in cyclically deformed TiAl polysynthetically twinned crystals has been examined by focusing on the effect of the Schmid factor (SF) for the operative slip systems. The decomposion of the 011 superlattice dislocations on (111) into 1/2[110]ordinary and 1/2[112]superlattice dislocations occurs more frequently with an increase in the ratio of the SF for the (111)1/2 [110] slip to that for the (111) [011] slip. The most effective factor in controlling the decomposition is the stress component acting for the motion of the resultant 1/2[110]dislocations.