PREPARATION OF ZrWMoO?-CONTAINING COMPOSITES WITH ZERO THERMAL EXPANSION PROPERTY USING Al(NO?)?.9H?O AS A SINTERING AID

摘要

Mixed oxide β-ZrWMoO?-containing composites with monoclinic zirconia (m-ZrO?) were prepared in search for zero thermal expansion ceramics over a wide temperature range. Thermomechanical analyzer (TMA) results indicate that the thermal expansion coefficients of the β-ZrWMoO?-containing composites decrease with increasing amount of β-ZrWMoO? and that the composite with 50 wt.% β-ZrWMoO? and 50 wt.% m-ZrO? exhibits near-zero thermal expansion from 30 to about 600°C. However, its relative density is low. The addition of a small amount of Al(NO?)?.9H?O as a sintering aid increases the density (possibly because the Al3? ion promotes sintering and densification) while affecting the structure and thermal expansion only insignificantly.