A Study of the Isothermal Section in the W-Fe-Co Ternary System at 1380K

The purpose of the present paper isto determine the composition range ofthe θ intermediate phase and establishthe phase equilibria relation in theW-Fe-Co ternary system.The experimentalresult was compared with the calculationof phase diagrams in Guillermet's work.1.Experimental ProcedureThe diffusion couple specimen usedin this investigation was prepared fromthe tungsten bar (99.96 wt-%),electro-