Among non-ferrous metallic materials, berylliumcopper
and its modifications have been known to
develop high strength by a process of precipitation.
The fact that these alloys suffer from the disadvantages
of high cost, certain property limitations and
health hazards during the handling of beryllium,
has instigated an extensive search for alternatives.
Many new alloys have been successfully developed
as substitutes, among which the Cu-Ni-Sn alloys
have been shown to develop high strength values
[1] surpassing that attainable in the best of the
copper-beryllium compositions. Such high
strengths have been attributed to the development
of a fine modulated structure as a result of a spinodal
decomposition. Typically, after suitable
mechanical treatment, it has been shown [2] that
yield strength values of the order of 1400 MPa can
result. However, in these alloys, on overageing, a
discontinuous precipitation sets in resulting in an
embrittling