| 摘要 |
PURPOSE:To obtain the title ceramic at low cost by bringing into contact with a heated ZrO2 ceramic a mixed gas comprising H2 gas and HC or CO gas activated by action of plasma to convert the surface layer of said ceramic into ZrC at relatively low temperature. CONSTITUTION:A ZrO2 ceramic contg. <=50mol% of tetragonal ZrO2, esp. pref. said ceramic contg. Y2O3 in the form of solid solution is put into a reaction vessel. A mixed gas comprising HC or CO gas and H2 gas is then introduced into said vessel, and concurrently with this, plasma is made to act on said mixed gas to effect excitation and dissociation of the HC or CO gas, resulting in activation. In this case, the mixing ratio for the HC or CO gas and the H2 gas is normally such as to be ca. 0.01-0.1 in C/H2. The pressure within the vessel is set at 30-300Torr and the ZrO2 ceramic is heated at 700-1000 deg.C in advance. And the above-mentioned mixed gas activated is brought into contact with said ceramic, thus obtaining the objective ZrO2 ceramic with its surface layer converted into ZrC. |
