摘要 |
PROBLEM TO BE SOLVED: To improve thermal shock, corrosion and wear resistances by firing a mixture of alumina, magnesia, spinel or zirconia with a powdery chromium oxide-aluminum mixture and a powdery silicon nitride-aluminum nitride mixture in an atmosphere of nitrogen. SOLUTION: A compsn. is prepd. by blending 10-50wt.% one or more kinds of aggregates selected from among alumina, magnesia, spinel and zirconia each having 0.3-1mm particle diameter with 25-60wt.% powdery chrominum oxide-aluminum mixture having a molar ratio of 1:2 and 20-40wt.% powdery silicon nitride-aluminum nitride mixture having a ratio of 1:(0.5-1). The compsn. is fired at >=1,400 deg.C in an atmosphere of nitrogen under atmospheric pressure optionally after press compacting at >=600 deg.C under >=10MPa pressure to obtain the objective sialon-contg. alumina-chrome composite refractories having <=5% porosity and contg. alumina, magnesia, spinel or zirconia uniformly dispersed in the sialon-alumina-chrome matrix. |