CHAPTER 3
EXPERIMENTAL PROCEDURE
3.1 Composition
Two major alloy compositions were chosen for this
investigation. They both represent potentially attractive
alloys for gas turbine blade applications. These two
alloys are designated as RSR 197 and RSR 209. They are
prepared by a powder metallurgy process developed at Pratt
and Whitney Aircraft Government Products Division. They
are two of a multitude of experimental alloys under
development for future high temperature turbine blade
materials. The RSR in the alloy designation is an acronym
for a rapid solidification process to be described
subsequently. The numbers 197 and 209 are arbitrary
numbers representative of the sequence in which the alloys
were prepared. The composition of these two alloys is
given in Table 3.1.
In the RSR process, the desired alloy is melted under
inert conditions (under argon gas) and allowed to impinge
in the molten state onto a rapidly rotating disc (Holiday
et al., 1978). The resulting spherical liquid metal
droplets are quenched in a stream of cooled He gas. The
powder is collected and canned under inert conditions.
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