【摘要】 以电熔镁砂、氮化硅与Al或Si为原料,制备 的试样经1400℃烧后制成了MgO-Si3N4复合材料, 研究了金属Al或Si对MgO-Si3N4复合材料强度的影 响。发现Al或Si的加入均可显著提高MgO-Si3N4复 合材料的常温耐压强度和高温抗折强度(1400℃)。 然后借助SEM和EDAX等手段研究了加入4%Al或 Si的MgO-Si3N4复合材料的显微结构,揭示了金属Al 和Si的增强作用机理:体系中的Al转化为晶须状的 氮氧化物,起纤维增韧作用;体系中的Si转化为粒状 或絮状的氮化硅,起颗粒增强作用。更多还原

【Abstract】 MgO-Si 3N 4 composites were prepared with 84%~88% fused magnesite,12% Si 3N 4 and 0~4% Al or Si.The influence of Al or Si on strength of the composite was researched.The results showed that the CCS and HMOR (1400 ℃) of MgO-Si 3N 4 composite could be enhanced obviously by adding Al and Si.The microstructure of MgO-Si 3N 4 composite containing Al or Si was studied by SEM and EDAX and the reinforcement mechanism by adding Al and Si on MgO-Si 3N 4 composite was analyzed.That was fibre reinforcement and particle reinforcement respectively.The reinforcement was contributed both by the aluminum oxynitride fibre that formed by Al reacting with oxygen and nitrogen in the composite and the silicon nitrides particles or floccules that formed by Si reacting with nitrogen in the composite.更多还原