Al2O3对氧化镁陶瓷烧结性及抗热震性的影响

本文以纳米氧化镁,硫酸铝和氨水为原料,采用共沉淀法制备表面由Al2O3前驱体包覆的MgO陶瓷.对烧后试样进行常温烧结性能和抗热震稳定性能检测.试样相组成的确定和显微结构分析是分别通过XRD和SEM手段来进行的.着重研究了由前驱体转化得到的Al2O3作为烧结助剂对氧化镁陶瓷的烧结性及抗热震性的影响.结果表明:加入Al2O3后,试样中生成了镁铝尖晶石,提高了试样的致密度,最大可达到3.48 g/cm3.在试样的显微结构中出现了大量微裂纹和粘连区域,一定程度上优化了试样的抗热震稳定性.

Effect of Al2O3 on Sintering and Thermal Shock Resistance of MgO Ceramic

Nano-magnesia powder adhered with alumina precursor was prepared with nano-magnesia, aluminum sulfate and ammonium hydroxide by using co-precipitation method.The sintering properties at room temperature and thermal shock resistance of sintering specimens were investigated.Phase composition and the microstructure of specimens were studied by XRD and SEM methods.The effect of alumina precursor that served as sintering aid on sintering and thermal shock resistance of magnesia ceramic was studied.The results suggest that the specimens after alumina added formed magnesium aluminate spinel that increased the sintering properties, maximum bulk density is 3.48 g/cm3.There are amounts of micro-cracks and conglutination areas in the microstructure that are contributed to the thermal shock resistance to some degree.