SIMULTANEOUS SAS AND 100 EXPERIMENTS ON PHASE-DECOMPOSITION AND REVERSION IN AL-LI BINARY-ALLOYS

Phase decomposition and reversion processes in Al-Li binary alloys hav e been studied by synchrotron-radiation small-angle/100 scattering exp eriments. The microstructure and its evolution obtained from small-ang le scattering (SAS) and 100 profiles during phase decomposition and re version are discussed. For the coarsening and reversion processes wher e a well defined interface between the delta' precipitates and the mat rix can be expected, the information obtained from the SAS and 100 pro files was essentially the same. On the other hand, the structural info rmation they convey can be different in the early stage of phase decom position. The interpretation of the SAS and 100 intensities by means o f an extension of the two-phase model has been examined.