含低α相氮化硅粉料的烧结特性

Sinterability of Silicon Nitride Powder with Low α-Phase Content

用自蔓延高温燃烧法合成制备的两种不同α相含量的氮化硅粉料α6(60%α)与α9(87%α),按α6/α9的不同比例混合组成三组不同α相含量的粉料,以Re(Y,La)2O3-AlN为烧结助剂,采用无压液相烧结的方法,考察了不同α6/α9比例的粉料对烧结密度、收缩率、烧失率、硬度的影响。结果表明:α6含量越多,烧结特性越好;密度和硬度值越高,烧失率也变大。当α6/α9=3:1时,试样相对密度为99.42%、烧失率为2.34%、线收缩率各向异性;硬度为11.72GPa。

Two different kinds of Si3N4 powders of 60%（α6） and 87%（α9）α-phase were synthesized by SHS method. They were mixed into three mixtures with three different rates of α6/α9, respectively. Re （Y, La）2O3-AlN as additives were used for liquid-phase sintering of Si3N4. The effects of different α6/α9 rates on density, shrinkage, weight-loss and hardness were studied. With increasing α6 content, the results of the sinterability was promoted, hardness was raised, and weight-loss was higher. The best was obtained to be density 97-99%,2.34% of weight-loss, 11.72GPa of hardness（Hv）.