Metallurgical Investigations with a 500 kV Electron Microscope

Abstract

Metallurgical investigations such as recrystallization, martensitic transformation and dynamic behaviors of dislocations have been carried out with a 500 kV electron microscope. The critical foil thickness sufficient to observe the same dynamic behaviors of these phenomena as occurred in bulk specimens is about 1 µ for recrystallization in aluminum and iron alloys, and 3 µ for cell formation in aluminum. On the other hand, foil thickness which allows observation with the 500 kV electron microscope is practically above 8 µ for annealed aluminum and above 2 µ for annealed iron and copper, and it is about one half in order to allow continuous observation of the dynamic behaviors of phenomena. It is concluded that the 500 kV electron microscope has great advantages for the dynamic investigations of metals, especially of materials with the atomic number smaller than 15 such as aluminum and many of ionic crystals.