Chemical process and solid solution formation in reactive hot pressed ZrB2-SiC ceramics doped with W

摘要

ZrB2-SiC doped with W was prepared from a mixture of Zr, Si, B4C and W via reactive hot pressing. The fully dense ZrB2-SiC-WB-ZrC ceramic was obtained at 1900 degrees C for 60 min under 30MPa in an argon atmosphere. Reaction path and solid solution characteristics of the starting powders were studied through a series of pressureless heat treatment at temperatures between 700 and 1500 degrees C. The solid solution phases of (Zr, W)B-2, (W, Zr)B and (Zr, W)C were formed directly by reactions between the precursors. Homogeneous distribution of solute atoms in solution and the solid solubilities were also studied.