ISOTHERMAL SECTION OF W-Ni-Cu SYSTEM AT 1017℃

The isothermal section of the W-Ni-Cu ternary system at 1017℃ was determined by meansof diffusion couple specimens,EMPA and X-ray diffraction.Body-centeredtetragonal Ni_4W and orthorhombic NiW but no NiW_2 observed in the W-Ni binary sys-tem at this temperature.The solubility ranges of W and Cu in Ni_4W are 16.95-20.51 at.-% and 0-4.36 at.-%,respectively.The maximum solubility of W in γ(Ni) is13.11 at.-%.