| Abstract: | The microstructure of four liquid-phase-sintered W-Ni-Fe altoys with 90-95 wt-%W was investigated by means of optical and electron microscope and X-ray diffraction. It was found that there would be a precipitated phase formed in the 90W-Ni-Fe alloy in presence of a little carbon impurity and under the condition of slow-cooling after Iiquid-phase sintering. It was identified as a kind of A_6B_6C carbide of compiex face-centered cubic system with lattice constant of 1.0935 nm. Its morphology varies with the cooling speed and its empiric formula can be written as(Ni, Fe)_6W_6C approximateiy. After studying the heat treatment, the formation or elimination of this phase can be controlled. |
