| 摘要 |
PURPOSE:To obtain the title brick excellent in heat shock resistance with little change in volume and physical properties in an oxidative or reducive atmosphere by press forming of a mixture comprising SiC aggregate, metallic Si powder and metallic Al powder followed by sintering in a N2 atmosphere. CONSTITUTION:Firstly, 100 pts.wt. of silicon carbide aggregate is homogeneously mixed with 15-20 pts.wt. of a blend comprising 67.5-88.8wt.% of metallic silicon powder, 3.4-8.5wt.% of metallic aluminum powder and 3-24wt.% of aluminum oxide powder. Thence, the resultant mixture is put to press forming and sintered in a nitrogen atmosphere at 1300-1500 deg.C thus obtaining the objective brick. The sintering atmosphere is required to be a nitrogen one in order to develop SIALON linkage during the sintering process. If <1300 deg.C in the sintering temperature, too long time is needed to produce firm SIALON linkage, therefore being impracticable. On the other hand, if >1500 deg.C, SIALON is rapidly formed on the surface of the sintered form to effect densification of said form; hence, a nitrogen gas cannot diffuse deep into the sintered form, therefore being unfavorable. |
