多孔氧化铝陶瓷晶粒异向生长机理研究

Investigation of Abnormal Grain Growth Mechanism of Porous Al_2O_3

采用直接发泡法制备多孔氧化铝陶瓷,研究了在1550℃烧结温度下Mg(NO3)2及TiO2对氧化铝陶瓷晶粒生长的影响机理,提出两个氧化铝陶瓷晶粒异向生长模型。结果表明:Mg(NO3)2对氧化铝晶体生长有抑制作用,而TiO2对氧化铝晶体生长有促进作用,同时采用Mg(NO3)和颗粒状TiO2作为烧结助剂能够促使氧化铝晶粒异向生长;并且在氩气气氛中1550℃烧结时,多孔氧化铝陶瓷晶粒各向异性生长更为显著。

Porous alumina materials are prepared by the two steps gel-casting and foaming synthesis method. The effects of Mg（NO3）2 and TiO2 agents. On the abnormal grain growth mechanism of Al2O3 are studied. Two models of the abnormal grain growth mechanism of AlO3 are proposed. The results show that the agent of Mg（NO3）2 could prevent the growth of alumina crystal, however, the agent of TiO2 is favorable to the growth of alumina crystal. Mg（NO3）2 and TiO： as sintering aids could cause the abnormal grain growth of α-Al203. Furthermore, it is found that the agents of TiO2 and Mg（NO3）2 could transform α-Al2O3 into the abnormal grain growth partially sintering at 1550%＇ for 3h in Ar.