MgO·nAl_2O_3透明陶瓷的制备及其物性  

Preparation and properties of non-stoichiometric MgO·nAl_2O_3 transparent ceramics

作　　者：黄存兵[1] 卢铁城[1] 雷牧云 黄存新 林理彬[1] 

机构地区：[1]四川大学物理系和辐射物理及技术教育部重点实验室,成都610064 [2]中非集团人工晶体研究院,北京100018

出　　处：《材料研究学报》2006年第1期49-53,共5页Chinese Journal of Materials Research

基　　金：国家自然科学基金50272040资助项目.

摘　　要：制备了非化学配比(n=1-2)的透明多晶MgO·nAl2O3陶瓷,研究了光学性质和力学性质与其物相和微观结构的关系．结果表明:非配比MgO·nAl2O3陶瓷主相的晶界处有Al2O3晶粒析出,其数量随着配比n的增大而增加．n=1-1．5的非配比透明陶瓷在紫外-可见波段与化学配比透明陶瓷一样具有较高的光学透过率,而n≥1．8陶瓷的透过率由于较多的第二相物质所引起的散射而有明显的下降．由于尖晶石晶粒性能改变和Al2O3晶粒的能量耗散等因素,非配比陶瓷的硬度和抗弯强度均比化学配比的高．过多的析出相引起的弱界面和缺陷裂纹可能导致陶瓷强度的下降,表现在其抗弯强度随着n的增大呈现先提高而后下降的变化规律．Non-stoichiometric MgO·nAl2O3（n=1～2） polycrstaylline transparent ceramics were prepared and the relationship between the optical and mechanical properties of ceramics and microstructures was investigated in this paper. The results show that non-stoichiometric ceramics have Al2O3 grains precipitated in the spinel-spinel grain boundary and the amount of Al2O3 grains increases with increasing n. The transmittance of non-stoichiometric MgO·nAl2O3 ceramics with n from 1 to 1.5 is as high as that of the stoichiometric （n=1） ceramics. The transmittance of MgO·nAl2O3 with n ≥1.8 is lower than others due to optical scattering caused by more Al2O3 grains. The flexural strength and hardness of non-stoichiometric ceramics are higher than that of stoichiometric ceramic. More precipitation maybe lead to weaker regions and original cracks, and flexural strength of nonstoichiometric ceramics obeys a rule of increasing followed by decreasing with increasing n.

关 键 词：无机非金属材料 MgO·nAl2O3 透明陶瓷 非化学配比 力学性能 透过率 

分 类 号：TB321[一般工业技术—材料科学与工程]