中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 14 No. 2 April 2004 |
（School of Materials Science and Engineering, Central South University,
Changsha 410083, China）
Abstract:An isothermal section of the Nb-W-Zr-C system at 1 100℃was established by means of multiphase diffusion couples along with electron microprobe analysis and X-ray diffraction analysis. The isothermal section consists of two single-phase regions,α(Nb, W, Zr) and (W, Nb)2Zr and one double-phase region,α(Nb, W, Zr)+(W, Nb)2Zr. It is concluded that (W, Nb)2Zr is an interstitial intermediate phase with the face-centered cubic (Cu2Mg) lattices. The maxi-
mum solid solubility of carbon in (W, Nb)2Zr phase is determined as about 4.18%C(mole fraction).The composition ranges of tungsten in the (W, Nb)2Zr phase are 55.41% to 65.98% and the maximum solid solubility of niobium in (W, Nb)2Zr is determined as 7.78%.
Key words: Nb-W-Zr-C quaternary system; diffusion couple; isothermal section
