SLURRY FOR PRODUCING POROUS CERAMICS AND POROUS CERAMICS OBTAINED BY USING THIS SLURRY

摘要

PURPOSE:To improve the water resistance and strength of a green cast mold and to suppress the reactivity with Ti (alloy) by incorporating transparent zirconia sol, fine refractory particles and org. binder into the above slurry. CONSTITUTION:The reaction product obtd. by bringing 1mol (as Zr) zirconium ammonium carbonate having pH8 to 10 and 10 to 20wt.% ZrO2 concn. and 0.02 to 4mol chelating agent into reaction is heated to 60 to 300 deg.C, by which the product is hydrolyzed and the transparent zirconia sol is obtd. The slurry is obtd. by compounding 1 to 5 pts.wt. fine refractory particles of 1 to 30mum average grain mix and 0.5 to 20 pts.wt. org. binder with 100 pts.wt. zirconia sol. The slurry having 10 to 90sec zahn-cap No. 5 viscosity is obtd. by compounding 0.1 to 10 pts.wt. nonionic surfactant and 0.1 to 10 pts.wt. defoaming agent with 100 pts.wt. this slurry. The green cast mold obtd. by immersing the casting pattern formed of wax into this slurry and drying the pattern, then removing the casting pattern is burned at 800 to 1600 deg.C, by which the porous ceramics is obtd.