An isothermal section of an equilibrium phase diagram in a Ni-Cr-W ternary system was experimentally determined at 1 000°C. Seventeen alloys with multiphase composition were equilibrated at 1 000°C for more than 10 000 h. Three terminal solid solutions: fcc γ nickel-rich, bcc α1chromium-rich and bcc α2 tungsten-rich phase, and two intermetallic compounds: β-Ni4W and σ phase, were observed as stable phases. Two-phase tie-lines and three-phase tie-triangles were determined by means of an electron microprobe analysis.
