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will decompose in a fashion similar to the decomposition
of the Ni-Mo alloys and will produce Ni-W phases similar
to those described in Section 2.2.1 (Mishra, 1979). For
example, N3W DO22 and N2W Pt2Mo phases are observed
during the decomposition of quenched and aged N4W
stoichiometric alloys (Mishra, 1979). These metastable
NixW phases are crystallographically identical to the
NixMo phases described in Section 2.2.1.
2.2.2.1 N14W
The N4W is a Dla superlattice with lattice parameters
a' = b' = 5.730 Angstroms and c* = 3.553 Angstroms. This
structure can be derived from the FCC alpha matrix with a
slight tetragonal distortion; here c'/c = .98. It is
isostructural and presumably isomorphous with N4M0.
2.2.2.2 N13W
This phase is crystallographically identical to N3M0
DO22 (see Section 2.2.1.2).
2.2.2.3 Ni?W
This phase is crystallographically identical to N2M0
Pt2Mo (see Section 2.2.1.3).
2.2.2.4 NiW
Equilibrium NiW is an orthorhombic phase (Walsh and
Donachie, 1973) with lattice constants a = 7.76, b =