THE EFFECT OF PLASTIC DEFORMATION ON T1 PRECIPITATION

The enhancement of T1 precipitation in Al-Li-Cu alloys by stretching prior to aging (i.e., cold work) and the subsequent increase in alloy strength has been documented [1]. The role of matrix dislocations in the nucleation and growth of T1 plates, however, has not been studied in detail. In this paper the effect of different levels of plastic strain on the T1 particle distributions as a function of aging time at 190 C will be quantified. Additionally, the precipitation mechanism will be explored in order to better understand the role of matrix dislocations as nucleation sites and their effect on T1 plate growth