429 24
artifact? To examine this question, the analyst can use pixel
masks of each phase selected from the Ni compositional map
(or the BSE image) to obtain the SUM spectrum, as shown in
. Figs. 24.18 (Fe-rich phase), 24.19 (Al-rich phase), 24.20
(Ni-intermediate phase), and 24.21 (Ni-rich phase). These
SUM spectra confirm that Fe is indeed present as a trace
constituent, with its highest level in the intermediate-Ni phase
where CFe = 0.0027 (2700 ppm), falling to CFe = 0.00038
(380 ppm) in the high-Ni phase and to CFe = 0.00030
(300 ppm) in the high-Al phase. Additionally, trace Cr at a
similar concentration is found in the Al-rich phase along with
the trace Fe.100000010000010000(^1000) Ni
Ni Al
Cr
Cr
Mn
Mn Fe
Fe
Ni
Ni
Cu
Cu
Zn
Zn
Raney1-Mask_
highFephase
Ni
Al
O
100
012345
Energy (keV)
Counts (Log)
6 78910
Ni
Ni
Ni Al
Al
Cr
Cr
Mn
Mn
Fe
Fe
Ni
CuNi
Cu
Zn
Zn
Raney1-Mask
highFe_phase
O
24000
22000
20000
18000
16000
14000
12000
10000
8000
6000
4000
2000
0
Counts
012345
Energy (keV)
6 78910
Ni
Fe=0.044
Al
Cr Mn
Al+NiL
Al+Al
Fe-rich phase
. Fig. 24.18 Raney nickel alloy XSI: mask of pixels corresponding to the Fe-rich phase and the corresponding SUM spectrum; the Fe peak corresponds
to C = 0.044 mass fraction
24.3 · Quantitative Compositional Mapping