data used for the analysis; XKi c 0, where i is one of the elements in the alloy. This
requirement for the K's to sum to zero is due a function of the mathematics used.
Additionally, overall effects of alloy segregation can be identified visually (from
the graphs as indicated by the overall changes in of K in the appropriate graphs) or
mathematically (B Ki l j, where i is one of the elements in alloy j). Whichever Y Ki j is
at a minimum for a set of alloys being compared, that alloy exhibits the least overall
amount of segregation of those alloys compared. The complete list of all of the
mathematical sums of k are listed in Table 5-1. The alloys in Table 5-1 are listed in order
of lowest Ki K to highest Y Ki .
Table 5-1: Y I Ki for the eighteen model alloys and CMSX-4 listed in order from lowest
to highest.
Alloy Y l Ki Alloy Y l Ki Alloy Y l Ki
LMSX-9 57.07 LMSX-16 152.57 LMSX-18 202.24
CMSX-4 69.07 LMSX-14 153.72 LMSX-17 222.65
LMSX-7 108.71 LMSX-15 158.29 LMSX-11 249.41
LMSX-8 128.99 LMSX-12 159.78
LMSX-4 132.11 LMSX-3 173.00
LMSX-10 140.75 LMSX-2 178.25
LMSX-5 147.01 LMSX-13 186.02
LMSX-1 150.88 LMSX-6 189.83
5.2.2. Cobalt Effects
The effect of Co addition on solidification and segregation were examined using
LMSX-1 (12.2 wt% Co), -2 (8 wt% Co), and -3 (4 wt% Co). LMSX-1 is based on the
chemistry of Rene N6 (12.5 wt% Co), and LMSX-3 is based on CMSX-10 (4 wt% Co).
All three of the alloys were examined in the as-cast condition to investigate each
elements segregation pattern and then compared against the varying Cr concentration to
evaluate the effects.