AlN-多型体陶瓷的研究 Ⅱ.AlN-多型体的力学性能和微观结构  

Studies on AlN-Polytypoids Ⅱ. The Mechanical Properties and microstructuves of AlN-Polytypoids

作　　者：王佩玲[1] 张炯[1] 贾迎新[1] 孙维莹[1] 

机构地区：[1]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《无机材料学报》2000年第4期756-760,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金重点项目资助!(59632100)

摘　　要：在研究了 ＡｌＮ－型体 １５Ｒ， １２Ｈ和 ２１Ｒ的形成特性的基础上［１］；本工作测定了它们的力学性能，并利用ＳＥＭ观察了显微结构．结果表明，尽管ＡＩＮ－多型体的力学性能较差，但是具有适当烧结添加剂的ＡＩＮ－多型体的抗折强度在室温至１２５０℃的范围内能保持不变，甚至提高５０％；尤其是１５Ｒ和１２Ｈ．ＡＩＮ－多型体的硬度随其组份向ＡｌＮ方向靠近而增加，即２１Ｒ的硬度最高（１２．７～１４．４ＧＰａ），１５Ｒ的硬度为最低（１．５～１２．８ＧＰａ）．ＡＩＮ－多型体的强度和断裂韧性与ＡｌＮ－多型体的类型之间没有这种明显的联系，它们的变化范围分别在３１３～３６６ＭＰａ和３．８～４．８ ＭＰａ·ｍ^（１／２）之间．本文依据 ＡＩＮ－多型体的结构特征及断裂形貌对它们的力学性能进行了讨论．Based on our previous study on formation and densification behavior of AIN-polytypoids (15R, 12H, 21R)[1], their mechanical properties and microstructure were studied. The results show that the AIN-polytypoid phases possess relatively poor mechanical properties, however, their fie-cural strength can remain constant(21R) or increase as high as 50%(15R and 12H) from room temperature till 1250℃. The hardness varies with the species of AIN-polytypoids and the additives used in a range of 11.5～14.4GPa(H_(v10)). The 15R compositions possess the lowest hardness varying from 11.5 to 12.8GPa. For 12H and 21R compositions, the varying range increases to 12.6～13.8GPa and 12.7～14.4GPa, respectively. The longer stacking sequence in AIN-rich polytypoids is responsible for its higher hardness because of the longer Burgers vector required for slip dislocations. The fracture toughness and fie-cural strength has no such close relationships to the type of AIN- polytypoids. They varied in the range of 3.8～4.8MPa·m^(1/2) and 313～366MPa, respectively. The pull out and micro-cracks formed in the AIN-polytypoids grains are supposedly the main mechanisms for the strengthening effect at high temperature.

关 键 词：多型体 稀土氧化物 力学性能 结构 氮化铝 陶瓷 

分 类 号：TQ174.758[化学工程—陶瓷工业] TQ174.1[化学工程—硅酸盐工业]