本文采用热压工艺研究了三种AlN－多型体：15R，12H和21R的致密化行为及形成过程．结果表明，AlN－多型体必须在存有少量烧结添加剂的条件下才能烧结致密，在所使用的添加剂中，Sm2O3·Al2O3为最有效，在加入2．5wt％时能使这三种多型体的密度在1600℃就接近完全致密．15R和12H的形成过程较为相似，分别在1550℃和1600℃之前，15R和12H随温度升高而增加，最高达95wt％以上，但过后随温度增加其量逐渐下降，同时12H和21R分别出现在15R和12H的组份中．21R的形成过程与它们相异甚大，在低温时先形成12H，随温度的增高，12H含量逐渐下降，而21R不断增加，在1750℃以上达100wt％．本文还对AlN－多型体的形成过程进行了讨论．
In the present work the densification behavior and reaction sequences of the three types of AlN-polytypoids 15R, 12H and 21R were
studied. The results show that it is necessary to put small amount of additives for achieving fully dense of AlN-polytypoids. Among
these additives explored, Sm2O3·Al2O3 is the most effective. With 2.5wt% SmAlO3, all these three polytypoids can reach near to
fully dense at 1600℃. 15R and 12H have similar reaction sequences. Below 1550℃ and 1600℃, 15R and 12H increase with increasing temperature respectively and reach to the top value around
95wt% and then both decrease with 12H and 21R occurring in 15R and 12H respectively. The formation of 21R is different from 15R and 12H. At lower
temperature, 12H forms firstly and with increasing temperature 12H decreases and 21R increases. Above 1750℃, pure 21R can be obtained. The
reaction sequences of these AlN-polytypoids were discussed in the paper.
参考文献
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