Influence of Rare earth oxides on Crystallization behavior and Sintering performance of Fused Quartz Ceramic Materials

摘要

Fused quartz granule (d_(50)=0.033mm) was used as raw material, Pr_6O_(11), Sm_2O_3, Gd_2O_3, Dy_2O_3 and Ho_2O_3 were used as additives with dosage of 2% each. Fused quartz ceramic materials were fabricated in reduction atmosphere at 1300°C, 1400°C and 1500°C for lh. Samples were examined apparent porosity, bending strength, thermal expansion rate (RT~1200°C), and analyzed by XRD and SEM. The results indicated that additives Pr_6O_(11), Sm_2O_3 and Dy_2O_3 had a bit inhibiting effect on crystallization of fused quartz sintered at 1300°C and 1400°C, Ho_2O_3 and Gd_2O_3 had more inhibiting effect on crystallization in samples sintered at various temperatures, sample containing Ho_2O_3 had least thermal expansion rate. Pr_6O_(11), Sm_2O_3 and Dy_2O_3 had few facilitating effect on sintering, Gd_2O_3 and Ho_2O_3 had more facilitating effect on sintering of fused quartz ceramic materials, samples with Gd_2O_3 and Ho_2O_3 had lower apparent porosity and higher bending strength and more compact micro structure. It can be deduced that Gd_2O_3 and Ho_2O_3 play the excellent role as the crystallization inhibitor to fused quartz materials.