Nature of an endothermic peak of As-quenched Al-11.8 mol%Li alloys

Abstract

In-situ and simultaneous synchrotron-radiation small-angle/100 scattering (SR-SAS/100) experiments have been performed at beam-line 15A of Photon Factory, KEK Japan. The structural change during heating as-quenched Al-11.8 mol%Li samples has been examined by analyzing SAS and 100 profiles. It was found that the endothermic reactions observed in differential scanning calorimetry (DSC) experiments around 400 K correspond to the disordering of ordered regions formed during quench. The microstructure formed during the quench has been discussed in terms of the change of the characteristic lengths for compositional fluctuation and that for ordering during heating.