アルミナ-ジルコニア-グラファイト耐火物の性質に及ぼすプロセス・パラメーターの影響(第2報) : 焼成温度及び時間

概要

論文の詳細を見る
Alumina-zirconia-graphite(AZG) materials are important refractories for AISI 304 stainless steel strip casting, which is especially used as slide gates and nozzles. AZG refractories were obtained through a baking technique using fused Al_2O_3, partially stabilized ZrO_2 and flake graphite as starting materials with Al, Si, and SiC powders as additives. A particle size distribution was according to the Furnas model for coarse Al_2O_3 (500-1000μm/medium Al_2O_3 (61-125 μm/fine Al_2O_3(<44μm in which the contents of coarse, medium and fine Al_2O_3 powders were varied with the constant amount of other fine particles in the matrix. The bulk density reached the values 3.29, 3.19 and 3.13 g・cm^<-3> when baked at 200℃ for 2, 2 and 2.5h, respectively. The apparent porosity decreased from 7.6 to 6.3% upon increasing the baking time at 160℃ from 0.5 to 2.5 h, and then gradually increased from 6.3 to 6.6% as the baking time increased from 2.5 to 3.0 h. The modulus of rupture was <80 MPa when the baking time was 1.5h for all samples formed at 150 MPa and baked at 200℃. On the other hand, the modulus of rupture increased sharply and attained a maximum value > 120 MPa for a baking time of 3.0 h. The erosion fraction (E_r) increased with increasing apparent porosity (P_0) and could be expressed E_r=0.30P_0-0.27.
2001-09-01