| 摘要 |
PURPOSE:To improve the dimensional accuracy of the subject product by preparing an aluminum titanate molded article having hollow shape and baking the molded article by heating the inner surface of the article at a specific temperature and heating the outer surface at a temperature higher than the heating temperature of the inner surface. CONSTITUTION:A slip is produced by mixing aluminum titanate powder, iron sesquioxide powder, a sintering assistant such as silicon oxide and a deflocculant such as ammonium polycarboxylate at specific weight ratios and adding water to the mixture. The slip is poured into a gypsum mold having a prescribed shape to deposit the powder on the wall and the excess slip is discharged to obtain a cylindrical aluminum titanate molded article 1. The molded article 1 is placed in an electric furnace 3 containing a pipe 2 held with a flange 20 and extending through the upper and lower walls. The electric furnace 3 is heated at a prescribed temperature while passing air through the pipe 2 to effect the thermal baking of the molded article 1 at the inner surface temperature of 1200-1750 deg.C and the outer surface temperature higher than the inner surface temperature. The obtained sintered aluminum titanate article 4 has high strength at the inner surface and low strength at the outer surface. |
