The ternary equilibrium state of the system copper-nickel-silicon relating to liquid was thoroughly investigated by thermal and X-ray analyses as well as microscopic examination, and heterogeneous equilibria were determined by the construction of many sectional diagrams using many specimens.
As shown in Fig. 2 (quantitatively drawn) and Fig. 3 (qualitatively drawn) the diagram is very complicated. The binary systems are not formed on the lines Cu-Ni₂Si, Cu-Ni₅Si₂, Cu-NiSi, Cu₃Si-Ni₂Si, Cu₃Si-Ni₅Si₂ and Cu₃Si-NiSi, the last one being liable to be taken for a binary system but clear microscopically that it is not formed on the line; accordingly no binary system does exist in this system. Moreover, the phases appearing in Cu-Si system do not form continuous solid solutions solutions with those in Ni-Si system.
The significant points in the diagram are as follows:-there exists a ternary compound ω in the composition range of about 12-15% of Si and about 11-12% of Ni, which is formed by the ternary peritectic reaction L+γ+θ→ω at 859°; the γ phase stated in the 1 st. report of this investigation is formed in the ternary system by the binary peritectic reaction L+γ'+γ. the line of this reaction having a peak of temperature at 954° (the point s₃';) and falling from this point to each side rich or poor in silicon.
The reactions and the ranges of 13 primary crystals, 26 monovariant curves and 13 non-variant points are given in Tables 1, 2, and 3.4 respectively.