Influence of La<sub>2</sub>O<sub>3</sub> Nanopowder on Crystallization Behavior and Sintering Performance of Fused Quartz Ceramic Materials

Abstract

Fused quartz granule was used as raw material, and La2O3 nanopowder was used as additive with dosages of 1wt %, 2 wt % and 3 wt %. Fused quartz ceramic materials were fabricated in reduction atmosphere at 1300 °C, 1350 °C and 1400 °C for 1 h, respectively. The properties of samples including apparent porosity, bending strength and thermal expansion ratio were measured. The results show that the sample with 2 wt % La2O3 nanopowder has the lowest apparent porosity and the highest bending strength, and sample added 1% nano-La2O3 has the best inhibiting effect on crystallization of fused quartz. The samples with La2O3 nanopowder adding have lower thermal expansion ratio than blank sample. The XRD and SEM results show that the diffraction peak intensity of quartz phase decrease and the microstructure of the samples become more compact, after the La2O3 nanopowder was added into fused quartz ceramics. It indicated that La2O3 nanopowder has excellent inhibiting effect on crystallization of fused quartz and facilitating effect on sintering of fused quartz ceramics.