A technique for the observation of rapid solidification and annealing of powders in a transmission electron microscope

Journal Article · Sat Jan 01 04:00:00 EST 1983 · Scr. Metall.; (United States)

DOI:https://doi.org/10.1016/0036-9748(83)90087-X· OSTI ID:5531584

Kaufman, M J; Fraser, H L

In the recent past, there has been considerable interest in the general area of rapid solidification processing (RSP). It is highly desirable to be able to make observations of not only the as-solidified microstructure of RSP materials, but also to determine its response to thermal excursions. This paper describes a new technique for in-situ studies of such processes where the electron beam in a TEM is used not only for imaging, diffraction and analytical purposes, but also as a local heating source. Thus, when making observations on submicron powders, produced by electrohydrodynamic atomization (EHD), it is possible to anneal and even melt particulate by focusing the electron beam in a controlled manner. The molten droplets can then be rapidly solidified by occluding the beam from the area of interest. A wide range of cooling rates may be achieved, the maximum being at least as rapid as that estimated for the EHD process, about 10/sup 5/ K/s (dependent on powder size). Two examples of the use of this technique are given. The first involves the melting, rapid solidification and subsequent heat treatment of an AL-4.5wt.%Cu alloy. The second is an example of how this technique may be used in studies of the crystallization of metallic glasses, in this case a Cu-45at.%Zr alloy.

• Research Organization: Department of Metallurgy and the Materials Research Laboratory, University of Illinois, 1304 W. Green, Urbana, IL 61801
• DOE Contract Number: AC02-76ER01198
• OSTI ID: 5531584
• Journal Information: Scr. Metall.; (United States), Journal Name: Scr. Metall.; (United States) Vol. 17:1; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
ANNEALING
APPROPRIATE TECHNOLOGY
ATOMIZATION
COOLING
COPPER ALLOYS
CRYSTAL STRUCTURE
ELECTROHYDRODYNAMICS
ELECTRON BEAM MELTING
ELECTRON MICROSCOPY
FLUID MECHANICS
HEAT TREATMENTS
HYDRODYNAMICS
MECHANICS
MELTING
METALLIC GLASSES
METALLURGY
MICROSCOPY
MICROSTRUCTURE
PHASE TRANSFORMATIONS
POWDER METALLURGY
POWDERS
SOLIDIFICATION
TRANSMISSION ELECTRON MICROSCOPY