Al2TiO5添加量对MgO-Al2TiO5复合陶瓷烧结及抗热震性的影响

以纳米MgO粉为原料,选用以纳米Al2O3粉和纳米TiO2粉经1500℃保温3 h烧结制备的Al2TiO5为添加剂,采用固相烧结法经1500℃保温3 h制备了Al2TiO5质量分数分别为0、5%、10%和20%的MgO-Al2TiO5复合陶瓷,并采用XRD、SEM和EDS等研究了Al2TiO5添加量对MgO-Al2TiO5复合陶瓷烧结性能及抗热震性能的影响。结果表明:添加Al2TiO5有利于促进复合陶瓷的烧结,其体积密度和线收缩率随Al2TiO5添加量的增加而增大,当Al2TiO5添加量为20%(w)时,其体积密度和线收缩率分别为3.68 g·cm-3和22.07%;当Al2TiO5添加量为10%(w)时,其抗热震性能最佳。Al2TiO5位于方镁石晶粒交界处,抑制方镁石晶粒生长,阻碍裂纹扩展,使MgO-Al2TiO5复合陶瓷的抗热震性能得到改善。

Effect of Al2TiO5 addition on sintering property and thermal shock resistance of MgO-Al2TiO5 composite ceramics

Al2TiO5 was prepared by sintering nano TiO2 and nano Al2O3 at 1500℃for 3 h.MgO-Al2TiO5 composite ceramics were prepared at 1500℃for 3 h by solid-state sintering,with nano MgO powders as raw materials and Al2TiO5 as additives.The effect of the Al2TiO5 addition(0,5%,10%and 20%by mass,the same hereinafter)on the sintering property and thermal shock resistance of the composite ceramics was investigated by XRD,SEM and EDS.The results show that the Al2TiO5 addition is benefit to the sintering of the composite ceramics;the bulk density and linear shrinkage of the composite ceramics increase with the increasing Al2TiO5 addition;when the Al2TiO5 addition is 20%,the bulk density and the linear shrinkage of the composite ceramics are 3.68 g·cm-3 and 22.07%,respectively;when the Al2TiO5 addition is 10%,the thermal shock resistance of the composite ceramics is optimal;Al2TiO5 lies at the grain boundaries,which hinders the crystal growth of periclase and prevents the crack propagation,thus improving the thermal shock resistance of the MgO-Al2TiO5 composite ceramics.