Direct Observation of the Aluminium-Silver Alloy by Electron Microscope

Abstract

Aluminium-silver (24 and 30%) alloys were quenched from 500°C and aged at room temperature. For transmission electron microscopy thin sections of the specimen were prepared by electro-polishing and ion-etching. The precipitation and the dissolution process were studied by heating the thin section in a furnace in the electron microscope. As a result, irregular stacking of {111} layers was observed to occur prior to the precipitation of the γ'-phase. The rate of dissolution of the precipitate at 540°C was also measured by means of ciné technique.