what would be expected from a binary Ni3Mo alloy, as

described in Section 2.2.5.1.

 A major question in this research was, what are the

compositions of the major phases, of the gamma prime and

gamma phases in the RSR alloys? This information is

needed in order to define the precipitation behavior of

the NixMo precipitates in the RSR alloys since in the

binary alloys, the precipitate types vary as a function of

composition, as described in Section 2.2.5. This was the

purpose for the EDS measurements described in Section

4.2. The experimental values for the gamma and gamma

prime compositions given in Table 5.3 vary enough from

alloy to alloy that only the approximate composition can

be determined. For the gamma prime phase in RSR 197,

excluding the 760 for 100 hour aging data, this average

composition is 77 + 1.4 % Ni, 4.75 + 1.18 % Mo, and 18.2 +

2 % Al, all in atomic percent. For gamma, again excluding

the data for the 760 C for 100 hour aging data, the

average values for the composition of this phase are 78.15

+ 3.2 % Ni, 16.4 + 1.0 % Mo, and 5.4 + 2.0 % Al, all in

atomic percent. It is reasonable, based on the binary

phase diagram solubility information shown in Figures 2.1

and 2.2, to take an average of the compositions even

though the solubility changes slightly with temperature

over the range of aging temperatures.