氮气压力对氮化硅烧结行为的影响

Influence of Nitrogen Gas Pressure on the Sintering Behavior of Si 3N 4 Ceramics

本文对在１４００～１７００℃温度范围内，分别在３０ａｔｍ和１ａｔｍ的Ｎ２中氮化硅陶瓷的烧结行为进行了比较研究，对比试验结果表明，在气压烧结过程中其致密化和α－β相变速率均滞后于常压烧结，晶界第二相组成也有所不同。为了避免高压氮气被包陷和致密化滞后，在气压烧结过程的前期（１７００℃）应避免使用高压氮气。

In this paper,the sintering behavior of Si 3N 4 ceramics in nitrogen gas respectively under 30 atm and 1 atm and in a temperature range of 1400℃-1700℃ was studied.The comparative test results show the densification and α-β phase transformation of Si 3N 4 ceramics in gas pressure sintering are delayed as compared with normal pressure sintering.In order to avoid the inclusion of high pressure gas and improve the densification at final stage,it could be better to use low pressure nitrogen gas at the early stage of gas pressure sintering of Si 3N 4 ceramics.